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Sample records for raman lidar profiles-temperature

  1. Raman Lidar Profiles–Temperature (RLPROFTEMP) Value-Added Product

    SciTech Connect (OSTI)

    Newsom, RK; Sivaraman, C; McFarlane, SA

    2012-10-31

    The purpose of this document is to describe the Raman Lidar Profiles–Temperature (RLPROFTEMP) value-added product (VAP) and the procedures used to derive atmospheric temperature profiles from the raw RL measurements. Sections 2 and 4 describe the input and output variables, respectively. Section 3 discusses the theory behind the measurement and the details of the algorithm, including calibration and overlap correction.

  2. Raman Lidar (RL) Handbook

    SciTech Connect (OSTI)

    Newsom, RK

    2009-03-01

    The Raman lidar at the ARM Climate Research Facility (ACRF) Southern Great Plains (SGP) Central Facility (SGPRL) is an active, ground-based laser remote sensing instrument that measures height and time resolved profiles of water vapor mixing ratio and several cloud- and aerosol-related quantities. The system is a non-commercial custom-built instrument developed by Sandia National Laboratories specifically for the ARM Program. It is fully computer automated, and will run unattended for many days following a brief (~5-minute) startup period. The self-contained system (requiring only external electrical power) is housed in a climate-controlled 8’x8’x20’ standard shipping container.

  3. Raman Lidar Receives Improvements

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

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  4. Raman lidar/AERI PBL Height Product

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Ferrare, Richard

    Planetary Boundary Layer (PBL) heights have been computed using potential temperature profiles derived from Raman lidar and AERI measurements. Raman lidar measurements of the rotational Raman scattering from nitrogen and oxygen are used to derive vertical profiles of potential temperature. AERI measurements of downwelling radiance are used in a physical retrieval approach (Smith et al. 1999, Feltz et al. 1998) to derive profiles of temperature and water vapor. The Raman lidar and AERI potential temperature profiles are merged to create a single potential temperature profile for computing PBL heights. PBL heights were derived from these merged potential temperature profiles using a modified Heffter (1980) technique that was tailored to the SGP site (Della Monache et al., 2004). PBL heights were computed on an hourly basis for the period January 1, 2009 through December 31, 2011. These heights are provided as meters above ground level.

  5. Raman lidar/AERI PBL Height Product

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Ferrare, Richard

    2012-12-14

    Planetary Boundary Layer (PBL) heights have been computed using potential temperature profiles derived from Raman lidar and AERI measurements. Raman lidar measurements of the rotational Raman scattering from nitrogen and oxygen are used to derive vertical profiles of potential temperature. AERI measurements of downwelling radiance are used in a physical retrieval approach (Smith et al. 1999, Feltz et al. 1998) to derive profiles of temperature and water vapor. The Raman lidar and AERI potential temperature profiles are merged to create a single potential temperature profile for computing PBL heights. PBL heights were derived from these merged potential temperature profiles using a modified Heffter (1980) technique that was tailored to the SGP site (Della Monache et al., 2004). PBL heights were computed on an hourly basis for the period January 1, 2009 through December 31, 2011. These heights are provided as meters above ground level.

  6. ARM: 10-minute Raman Lidar: aerosol scattering ratio and backscattering coefficient profiles, from first Ferrare algorithm

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Newsom, Rob; Goldsmith, John

    1998-03-01

    10-minute Raman Lidar: aerosol scattering ratio and backscattering coefficient profiles, from first Ferrare algorithm

  7. ARM: 10-minute Raman Lidar: aerosol extinction profiles and aerosol optical thickness, from first Ferrare algorithm

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Chitra Sivaraman; Connor Flynn

    1998-03-01

    10-minute Raman Lidar: aerosol extinction profiles and aerosol optical thickness, from first Ferrare algorithm

  8. ARM: 1-minute Raman Lidar: aerosol scattering ratio and backscattering coefficient profiles, from first Ferrare algorithm

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Chitra Sivaraman; Connor Flynn

    2004-10-01

    1-minute Raman Lidar: aerosol scattering ratio and backscattering coefficient profiles, from first Ferrare algorithm

  9. ARM: 2-minute Raman Lidar: aerosol scattering ratio and backscattering coefficient profiles, from first Ferrare algorithm

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Sivaraman, Chitra; Flynn, Connor

    2004-10-01

    2-minute Raman Lidar: aerosol scattering ratio and backscattering coefficient profiles, from first Ferrare algorithm

  10. ARM: 1-minute Raman Lidar: aerosol extinction profiles and aerosol optical thickness, from first Ferrare algorithm

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Chitra Sivaraman; Connor Flynn

    2004-10-01

    1-minute Raman Lidar: aerosol extinction profiles and aerosol optical thickness, from first Ferrare algorithm

  11. ARM: 10-second Raman Lidar: aerosol scattering ratio and backscattering coefficient profiles, from first Ferrare algorithm

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Chitra Sivaraman; Connor Flynn

    2004-10-01

    10-second Raman Lidar: aerosol scattering ratio and backscattering coefficient profiles, from first Ferrare algorithm

  12. ARM: 10-second Raman Lidar: aerosol scattering ratio and backscattering coefficient profiles, from first Ferrare algorithm

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Chitra Sivaraman; Connor Flynn

    10-second Raman Lidar: aerosol scattering ratio and backscattering coefficient profiles, from first Ferrare algorithm

  13. ARM: 10-minute Raman Lidar: aerosol scattering ratio and backscattering coefficient profiles, from first Ferrare algorithm

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Chitra Sivaraman; Connor Flynn

    10-minute Raman Lidar: aerosol scattering ratio and backscattering coefficient profiles, from first Ferrare algorithm

  14. ARM: 10-minute Raman Lidar: aerosol extinction profiles and aerosol optical thickness, from first Ferrare algorithm

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Chitra Sivaraman; Connor Flynn

    10-minute Raman Lidar: aerosol extinction profiles and aerosol optical thickness, from first Ferrare algorithm

  15. ARM: 2-minute Raman Lidar: aerosol scattering ratio and backscattering coefficient profiles, from first Ferrare algorithm

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Sivaraman, Chitra; Flynn, Connor

    2-minute Raman Lidar: aerosol scattering ratio and backscattering coefficient profiles, from first Ferrare algorithm

  16. ARM: 1-minute Raman Lidar: aerosol extinction profiles and aerosol optical thickness, from first Ferrare algorithm

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Chitra Sivaraman; Connor Flynn

    1-minute Raman Lidar: aerosol extinction profiles and aerosol optical thickness, from first Ferrare algorithm

  17. ARM: 1-minute Raman Lidar: aerosol scattering ratio and backscattering coefficient profiles, from first Ferrare algorithm

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Chitra Sivaraman; Connor Flynn

    1-minute Raman Lidar: aerosol scattering ratio and backscattering coefficient profiles, from first Ferrare algorithm

  18. ARM: 10-minute TEMPORARY Raman Lidar: aerosol scattering ratio and backscattering coefficient profiles, from first Ferrare algorithm

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Sivaraman, Chitra; Flynn, Connor

    2010-12-15

    10-minute TEMPORARY Raman Lidar: aerosol scattering ratio and backscattering coefficient profiles, from first Ferrare algorithm

  19. ARM: 10-minute TEMPORARY Raman Lidar: aerosol extinction profiles and aerosol optical thickness, from first Ferrare algorithm

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Sivaraman, Chitra; Flynn, Connor

    2010-12-15

    10-minute TEMPORARY Raman Lidar: aerosol extinction profiles and aerosol optical thickness, from first Ferrare algorithm

  20. ARM: 10-minute TEMPORARY Raman Lidar: aerosol extinction profiles and aerosol optical thickness, from first Ferrare algorithm

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Sivaraman, Chitra; Flynn, Connor

    10-minute TEMPORARY Raman Lidar: aerosol extinction profiles and aerosol optical thickness, from first Ferrare algorithm

  1. ARM: 10-minute TEMPORARY Raman Lidar: aerosol scattering ratio and backscattering coefficient profiles, from first Ferrare algorithm

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Sivaraman, Chitra; Flynn, Connor

    10-minute TEMPORARY Raman Lidar: aerosol scattering ratio and backscattering coefficient profiles, from first Ferrare algorithm

  2. DOE/SC-ARM/TR-120 Raman Lidar Profiles-Temperature

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

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  3. ARM: 10-minute Raman Lidar: aerosol depolarization profiles and single layer cloud optical depths from first Turner algorithm

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Chitra Sivaraman; Connor Flynn

    1998-03-01

    10-minute Raman Lidar: aerosol depolarization profiles and single layer cloud optical depths from first Turner algorithm

  4. ARM: 10-minute Raman Lidar: aerosol depolarization profiles and single layer cloud optical depths from first Turner algorithm

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Chitra Sivaraman; Connor Flynn

    10-minute Raman Lidar: aerosol depolarization profiles and single layer cloud optical depths from first Turner algorithm

  5. Raman lidar and MPL Measurements during ALIVE

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

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  6. Remote sensing of seawater and drifting ice in Svalbard fjords by compact Raman LIDAR

    E-Print Network [OSTI]

    Bunkin, Alexey F; Lednev, Vasily N; Lushnikov, Dmitry L; Marchenko, Aleksey V; Morozov, Eugene G; Pershin, Sergey M; Yulmetov, Renat N

    2013-01-01

    A compact Raman LIDAR system for remote sensing of sea and drifting ice was developed at the Wave Research Center at the Prokhorov General Physics Institute of the RAS. The developed system is based on a diode pumped solid state YVO4:Nd laser combined with compact spectrograph equipped with gated detector. The system exhibits high sensitivity and can be used for mapping or depth profiling of different parameters within many oceanographic problems. Light weight (~20 kg) and low power consumption (300 W) make possible to install the device on any vehicle including unmanned aircraft or submarine system. The Raman LIDAR presented was used for Svalbard fjords study and analysis of different influence of the open sea and glaciers on the water properties. Temperature, phytoplankton, and dissolved organic matter distributions in the seawater were studied in the Ice Fjord, Van Mijen Fjord and Rinders Fjord. Drifting ice and seawater in the Rinders Fjord were characterized by the Raman spectroscopy and fluorescence. It...

  7. Raman Lidar Measurements of Aerosols and Water Vapor During the May 2003 Aerosol IOP

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

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  8. Raman Lidar

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

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  9. Femtosecond Coherent Anti-Stokes Raman Spectroscopy (CARS) As Next Generation Nonlinear LIDAR Spectroscopy and Microscopy

    SciTech Connect (OSTI)

    Ooi, C. H. Raymond

    2009-07-10

    Nonlinear spectroscopy using coherent anti-Stokes Raman scattering and femtosecond laser pulses has been successfully developed as powerful tools for chemical analysis and biological imaging. Recent developments show promising possibilities of incorporating CARS into LIDAR system for remote detection of molecular species in airborne particles. The corresponding theory is being developed to describe nonlinear scattering of a mesoscopic particle composed of complex molecules by laser pulses with arbitrary shape and spectral content. Microscopic many-body transform theory is used to compute the third order susceptibility for CARS in molecules with known absorption spectrum and vibrational modes. The theory is combined with an integral scattering formula and Mie-Lorentz formulae, giving a rigorous formalism which provides powerful numerical experimentation of CARS spectra, particularly on the variations with the laser parameters and the direction of detection.

  10. High Spectral Resolution Infrared and Raman Lidar Observations for the ARM Program: Clear and Cloudy Sky Applications

    SciTech Connect (OSTI)

    Henry Revercomb, David Tobin, Robert Knuteson, Lori Borg, Leslie Moy

    2009-06-17

    This grant began with the development of the Atmospheric Emitted Radiance Interferometer (AERI) for ARM. The AERI has provided highly accurate and reliable observations of downwelling spectral radiance (Knuteson et al. 2004a, 2004b) for application to radiative transfer, remote sensing of boundary layer temperature and water vapor, and cloud characterization. One of the major contributions of the ARM program has been its success in improving radiation calculation capabilities for models and remote sensing that evolved from the multi-year, clear-sky spectral radiance comparisons between AERI radiances and line-by-line calculations (Turner et al. 2004). This effort also spurred us to play a central role in improving the accuracy of water vapor measurements, again helping ARM lead the way in the community (Turner et al. 2003a, Revercomb et al. 2003). In order to add high-altitude downlooking AERI-like observations over the ARM sites, we began the development of an airborne AERI instrument that has become known as the Scanning High-resolution Interferometer Sounder (Scanning-HIS). This instrument has become an integral part of the ARM Unmanned Aerospace Vehicle (ARM-UAV) program. It provides both a cross-track mapping view of the earth and an uplooking view from the 12-15 km altitude of the Scaled Composites Proteus aircraft when flown over the ARM sites for IOPs. It has successfully participated in the first two legs of the “grand tour” of the ARM sites (SGP and NSA), resulting in a very good comparison with AIRS observations in 2002 and in an especially interesting data set from the arctic during the Mixed-Phase Cloud Experiment (M-PACE) in 2004. More specifically, our major achievements for ARM include 1. Development of the Atmospheric Emitted Radiance Interferometer (AERI) to function like a satellite on the ground for ARM, providing a steady stream of accurately calibrated spectral radiances for Science Team clear sky and cloud applications (Knuteson et al. 2004a), 2. Detailed radiometric calibration and characterization of AERI radiances, with uncertainty estimates established from complete error analyses and proven by inter-comparison tests (Knuteson et al. 2004b), 3. AERI data quality assessment and maintenance over the extended time frames needed to support ARM (Dedecker et al., 2005) 4. Key role in the radiative transfer model improvements from the AERI/LBLRTM QME (Turner et al. 2004) and AERI-ER especially from the SHEBA experiment (Tobin et al. 1999), 5. Contributed scientific and programmatic leadership leading to significant water vapor accuracy improvements and uncertainty assessments for the low to mid troposphere (Turner et al. 2003a, Revercomb et al. 2003), 6. Leadership of the ARM assessment of the accuracy of water vapor observations from radiosondes, Raman Lidar and in situ aircraft observations in the upper troposphere and lower stratosphere (Tobin et al. 2002, Ferrare et al. 2004), 7. New techniques for characterizing clouds from AERI (DeSlover et al. 1999, Turner 2003b, Turner et al. 2003b), 8. Initial design and development of the Scanning-HIS aircraft instrument and application to ARM UAV Program missions (Revercomb et al. 2005), and 9. Coordinated efforts leading to the use of ARM observations as a key validation tool for the high resolution Atmospheric IR Sounder on the NASA Aqua platform (Tobin et al. 2005a) 10. Performed ARM site and global clear sky radiative closure studies that shows closure of top-of-atmosphere flux at the level of ~1 W/m2 (Moy et al 2008 and Section 3 of this appendix) 11. Performed studies to characterize SGP site cirrus cloud property retrievals and assess impacts on computed fluxes and heating rate profiles (Borg et al. 2008 and Section 2 of this appendix).

  11. Sandia Energy - ARM Raman Lidar Development

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Monitoring (ARM) program, measurements of water vapor profiles at high temporal and vertical resolution was deemed to be critical for both the radiative-transfer and...

  12. Sandia Energy - ARM Raman Lidar Applications

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Monitoring (ARM) program, measurements of water vapor profiles at high temporal and vertical resolution was deemed to be critical for both the radiative-transfer and...

  13. Comments on: ARM Raman Lidar Applications

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

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  14. Comments on: ARM Raman Lidar Development

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

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  15. Sandia Energy - ARM Raman Lidar Applications

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

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  16. Sandia Energy - ARM Raman Lidar Development

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

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  17. Ice thickness measurements by Raman scattering

    E-Print Network [OSTI]

    Pershin, Sergey M; Klinkov, Vladimir K; Yulmetov, Renat N; Bunkin, Alexey F

    2014-01-01

    A compact Raman LIDAR system with a spectrograph was used for express ice thickness measurements. The difference between the Raman spectra of ice and liquid water is employed to locate the ice-water interface while elastic scattering was used for air-ice surface detection. This approach yields an error of only 2 mm for an 80-mm-thick ice sample, indicating that it is promising express noncontact thickness measurements technique in field experiments.

  18. Raman Nanometrology of Graphene

    E-Print Network [OSTI]

    Calizo, Irene Gonzales

    2009-01-01

    13 Optical image of the graphene layers. . . . . .Micro-Raman Spectroscopy of Grapheneand Graphene Multi-Layers . . . . Raman Spectroscopy

  19. Using CO2 Lidar for Standoff Detection of a Perfluorocarbon Tracer in Air

    SciTech Connect (OSTI)

    Heiser,J.H.; Smith, S.; Sedlacek, A.

    2008-02-06

    The Tag, Track and Location System Program (TTL) is investigating the use of PFTs as tracers for tagging and tracking items of interest or fallen soldiers. In order for the tagging and tracking to be valuable there must be a location system that can detect the PFTs. This report details the development of an infrared lidar platform for standoff detection of PFTs released into the air from a tagged object or person. Furthering work performed using a table top lidar system in an indoor environment; a mobile mini lidar platform was assembled using an existing Raman lidar platform, a grating tunable CO{sub 2} IR laser, Judson HgCdTe detector and miscellaneous folding optics and electronics. The lidar achieved {approx}200 ppb-m sensitivity in laboratory and indoor testing and was then successfully demonstrated at an outdoor test. The lidar system was able to detect PFTs released into a vehicle from a distance of 100 meters. In its final, fully optimized configuration the lidar was capable of repeatedly detecting PFTs in the air released from tagged vehicles. Responses were immediate and clear. This report details the results of a proof-of-concept demonstration for standoff detection of a perfluorocarbon tracer (PFT) using infrared lidar. The project is part of the Tag, Track and Location System Program and was performed under a contract with Tracer Detection Technology Corp. with funding from the Office of Naval Research. A lidar capable of detecting PFT releases at distance was assembled by modifying an existing Raman lidar platform by incorporating a grating tunable CO{sub 2} IR laser, Judson HgCdTe detector and miscellaneous folding optics and electronics. The lidar achieved {approx}200 ppb-m sensitivity in laboratory and indoor testing and was successfully demonstrated at an outdoor test. The demonstration test (scripted by the sponsor) consisted of three parked cars, two of which were tagged with the PFT. The cars were located 70 (closest) to 100 meters (farthest) from the lidar (the lidar beam path was limited by site constraints and was {approx}100 meters). When one door of each of the cars was opened (sequentially), the lidar was clearly able to determine which vehicles had been tagged and which one was not. The lidar is probably capable of greater than 0.5 kilometer standoff distances based on the extreme amount of signal return achieved (so much that the system had to be de-tuned). The BNL lidar system, while optimized to the extent possible with available parts and budget, was not as sensitive as it could be. Steps to improve the lidar are detailed in this report and include using a better laser system (for more stable power output), dual wavelengths (to improve the sensitivity and allow common mode noise reduction and to allow the use of the lidar in a scanning configuration), heterodyning (for range resolved PFT detection) and an off-axis optical configuration (for improved near field sensitivity).

  20. ARM - PI Product - Raman lidar/AERI PBL Height Product

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

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  1. Doppler Lidar (DL) Handbook

    SciTech Connect (OSTI)

    Newsom, RK

    2012-02-13

    The Doppler lidar (DL) is an active remote sensing instrument that provides range- and time-resolved measurements of radial velocity and attenuated backscatter. The principle of operation is similar to radar in that pulses of energy are transmitted into the atmosphere; the energy scattered back to the transceiver is collected and measured as a time-resolved signal. From the time delay between each outgoing transmitted pulse and the backscattered signal, the distance to the scatterer is inferred. The radial or line-of-sight velocity of the scatterers is determined from the Doppler frequency shift of the backscattered radiation. The DL uses a heterodyne detection technique in which the return signal is mixed with a reference laser beam (i.e., local oscillator) of known frequency. An onboard signal processing computer then determines the Doppler frequency shift from the spectra of the heterodyne signal. The energy content of the Doppler spectra can also be used to determine attenuated backscatter.

  2. Raman Nanometrology of Graphene

    E-Print Network [OSTI]

    Calizo, Irene Gonzales

    2009-01-01

    x10 visible x50 visible x40 near UV x50 near UV x50 LWDvisible, LWD Raman Spectroscopy Techniques One, two, and

  3. Position Announcement Postdoctoral Research Associate Lidar Remote Sensing

    E-Print Network [OSTI]

    Salvaggio, Carl

    Position Announcement Postdoctoral Research Associate ­ Lidar Remote Sensing Department Summary: The employee will provide remote sensing expertise and conduct research in lidar remote sensing from advanced terrestrial, airborne, and satellite remote sensing platforms, including UASs (Unmanned

  4. Heterodyne lidar for chemical sensing

    SciTech Connect (OSTI)

    Oldenborg, R. C. (Richard C.); Tiee, J. J. (Joe J.); Shimada, T. (Tsutomu); Wilson, C. W. (Carl W.); Remelius, D. K. (Dennis K.); Fox, Jay; Swim, Cynthia

    2004-01-01

    The overall objective is to assess the detection performance of LWIR (long wavelength infrared) coherent Lidar systems that potentially possess enhanced effluent detection capabilities. Previous work conducted by Los Alamos has demonstrated that infrared DIfferential Absorption Lidar (DIAL) is capable of detecting chemicals in plumes from long standoff ranges. Our DIAL approach relied on the reflectivity of topographical targets to provide a strong return signal. With the inherent advantage of applying heterodyne transceivers to approach single-photon detection in LWIR, it is projected that marked improvements in detection range or in spatial coverage can be attained. In some cases, the added photon detection sensitivity could be utilized for sensing 'soft targets', such as atmospheric and threat aerosols where return signal strength is drastically reduced, as opposed to topographical targets. This would allow range resolved measurements and could lead to the mitigation of the limiting source of noise due to spectral/spatial/temporal variability of the ground scene. The ability to distinguish normal variations in the background from true chemical signatures is crucial to the further development of sensitive remote chemical sensing technologies. One main difficulty in demonstrating coherent DIAL detection is the development of suitable heterodyne transceivers that can achieve rapid multi-wavelength tuning required for obtaining spectral signature information. LANL has recently devised a novel multi-wavelength heterodyne transceiver concept that addresses this issue. A 5-KHz prototype coherent CO{sub 2} transceiver has been constructed and is being now used to help address important issues in remote CBW agent standoff detection. Laboratory measurements of signal-to-noise ratio (SNR) will be reported. Since the heterodyne detection scheme fundamentally has poor shot-to-shot signal statistics, in order to achieve sensitive detection limits, favorable averaging statistics have to be validated. The baseline coherent DIAL detection sensitivity that can be achieved averaging multiple laser pulses and by comparisons of different wavelengths will be demonstrated. Factors that are presently limiting performance and attempts to circumvent these issues will be discussed.

  5. REFURBISHMENT AND UPGRADE OF FE BOLTZMANN/RAYLEIGH TEMPERATURE LIDAR AT BOULDER FOR A MCMURDO LIDAR CAMPAIGN IN ANTARCTICA

    E-Print Network [OSTI]

    Chu, Xinzhao

    REFURBISHMENT AND UPGRADE OF FE BOLTZMANN/RAYLEIGH TEMPERATURE LIDAR AT BOULDER FOR A MCMURDO LIDAR conditions, refurbishment and upgrade of the system was necessary in order to restore its performance. More

  6. Raman accumulator as a fusion laser driver

    DOE Patents [OSTI]

    George, E.V.; Swingle, J.C.

    1982-03-31

    Apparatus for simultaneous laser pulse amplification and compression, using multiple pass Raman scattering in one Raman cell and pulse switchout from the optical cavity through use of a dichroic device associated with the Raman cell.

  7. Scanning angle Raman spectroscopy: Investigation of Raman scatter enhancement techniques for chemical analysis

    SciTech Connect (OSTI)

    Meyer, Matthew W.

    2013-03-14

    This thesis outlines advancements in Raman scatter enhancement techniques by applying evanescent fields, standing-waves (waveguides) and surface enhancements to increase the generated mean square electric field, which is directly related to the intensity of Raman scattering. These techniques are accomplished by employing scanning angle Raman spectroscopy and surface enhanced Raman spectroscopy. A 1064 nm multichannel Raman spectrometer is discussed for chemical analysis of lignin. Extending dispersive multichannel Raman spectroscopy to 1064 nm reduces the fluorescence interference that can mask the weaker Raman scattering. Overall, these techniques help address the major obstacles in Raman spectroscopy for chemical analysis, which include the inherently weak Raman cross section and susceptibility to fluorescence interference.

  8. Lidar techniques for search and rescue

    SciTech Connect (OSTI)

    Cabral, W.L.

    1985-01-01

    Four techniques for using LIDAR in Search and Rescue Operations will be discussed. The topic will include laser retroreflection, laser-induced fluorescence in the visible, laser-induced fluorescence during daylight hours, and laser-induced fluorescence in the uv. These techniques use high-repetition rate lasers at a variety of frequencies to induce either fluorescence in dye markers or retroreflection from plastic corner cubes on life preservers and other emergency markers.

  9. Posters Scanning Raman Lidar Measurements of Atmospheric Water Vapor and Aerosols

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration wouldMass mapSpeedingProgram Guidelines This document outlines the majorL.Posters955 Posters

  10. Oil spill fluorosensing lidar for inclined onshore or shipboard operation

    E-Print Network [OSTI]

    Oldenburg, Carl von Ossietzky Universität

    Oil spill fluorosensing lidar for inclined onshore or shipboard operation Renata Karpicz, Andrej An oil spill detection fluorosensing lidar for onshore or shipboard operation is described. Some the back- ground water column fluorescence from signals such as yellow substance. This enables oil

  11. Ris-R-Report LIDAR Wind Speed Measurements from a

    E-Print Network [OSTI]

    Risø-R-Report LIDAR Wind Speed Measurements from a Rotating Spinner: "SpinnerEx 2009" Nikolas: LIDAR wind speed measurements from a rotating spinner (SpinnerEx 2009) Division: Wind Energy Division application of remote sensing techniques in wind energy, the feasibility of upwind observations via a spinner

  12. Lidar on the Phoenix mission to Mars James Whiteway,1

    E-Print Network [OSTI]

    Duck, Thomas J.

    Lidar on the Phoenix mission to Mars James Whiteway,1 Michael Daly,2 Allan Carswell,3 Thomas Duck,4 from the surface of Mars as part of the Phoenix mission. This will measure the height profile, and C. Cook (2008), Lidar on the Phoenix mission to Mars, J. Geophys. Res., 113, E00A08, doi:10

  13. Validation of Innovative Exploration Technologies for Newberry Volcano: LIDAR of Newberry Volcano 2012

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Jaffe, Todd

    2012-01-01

    Validation of Innovative Exploration Technologies for Newberry Volcano: LIDAR of Newberry Volcano 2012

  14. Validation of Innovative Exploration Technologies for Newberry Volcano: LIDAR of Newberry Volcano 2012

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Jaffe, Todd

    Validation of Innovative Exploration Technologies for Newberry Volcano: LIDAR of Newberry Volcano 2012

  15. A study on Raman Injection Laser 

    E-Print Network [OSTI]

    Liu, Debin

    2005-11-01

    The Raman Injection Laser is a new type of laser which is based on triply resonant stimulated Raman scattering between quantum confined states within the active region of a Quantum Cascade Laser that serves as an internal optical pump. The Raman...

  16. JOURNAL OF RAMAN SPECTROSCOPY J. Raman Spectrosc. 2003; 34: 769775

    E-Print Network [OSTI]

    Downs, Robert T.

    . An additional change in the spectrum is observed between 7.7 and 8.9 GPa, possibly due to the formation for these changes have been the subject of much study.2 A recently discovered phase transition in pyroxenes display C1 site symmetry. According to factor group analysis, there are 14 Ag and 16 Bg Raman-active modes

  17. Rayleigh lidar observations of mesosphere temperature structure

    SciTech Connect (OSTI)

    Meriwether, J.W.; Dao, P.D.; Mcnutt, R.T.; Klemetti, W.; Moskowitz, W.; Davidson, G. [Hanscom Air Force Base, MA (United States)]|[PhotoMetrics, Inc., Woburn, MA (United States)

    1994-08-01

    Ground-based observations of atmospheric density profiles to 92 km were obtained for four successive seasons between summer 1989 and spring 1990. These results were obtained with a powerful Rayleigh lidar facility located at Wright Patterson Air Force Base (Dayton, Ohio). This instrument combined a 14-W XeF laser transmitter with a 2.54-m receiver mirror to observe returns from altitudes between 40 and 95 km. Analysis of the scale height dependence of the density profiles produced temperatures with a measurement error of about 5 K (approximately 2.5%) at 90 km when the lidar data was averaged for 20 min. and smoothed in height over 2.7 km. Examination of these profiles for the total of 18 nights showed that there often existed in the mesophere a layer of enhanced temperatures when compared with the U.S. standard profile. The layer centroid height was about 85 km for summer and 70 to 75 km for winter. Data obtained for the equinoctial periods showed the amplitude of these layers to be weak. The winter temperature profiles showed evidence for long-period waves passing through the region of the thermal anomaly while the equinox profiles revealed more sporadic wave activity with shorter vertical wavelengths. Both the winter and summer temperature data displayed regions where the observed lapse rate approached the adiabatic lapse rate. In the summer the wave activity near the iversion layer was weak.

  18. Atmospheric Data, Images, and Animations from Lidar Instruments used by the University of Wisconsin Lidar Group

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    The Space Science and Engineering Center is a research and development center affiliated with the University of Wisconsin-Madison’s Graduate School. Its primary focus is on geophysical research and technology to enhance understanding of the atmosphere of Earth, the other planets in the Solar System, and the cosmos. SSEC develops new observing tools for spacecraft, aircraft, and ground-based platforms, and models atmospheric phenomena. The Center receives, manages and distributes huge amounts of geophysical data and develops software to visualize and manipulate these data for use by researchers and operational meteorologists all over the world.[Taken from About SSEC at http://www.ssec.wisc.edu/overview/] A huge collection of data products, images, and animations comes to the SSEC from the University of Wisconsin Lidar Group. Contents of this collection include: • An archive of thousands of Lidar images acquired before 2004 • Arctic HSRL, MMCR, PAERI, MWR, Radiosonde, and CRAS forecast data Data after May 1, 2004 • MPEG animations and Lidar Multiple Scattering Models

  19. Mitigation of Coastal Bluff Instability in San Diego County, California/Evaluating Seacliff Morphology and Erosion Control in San Diego County Using LIDAR and GIS

    E-Print Network [OSTI]

    Ashford, Scott

    2005-01-01

    County Using LIDAR and GIS In order to evaluate seacliffgeographic information systems (GIS) analysis. LIDAR is the

  20. Automatic registration of LIDAR and optical images of urban scenes

    E-Print Network [OSTI]

    Mastin, Dana Andrew

    Fusion of 3D laser radar (LIDAR) imagery and aerial optical imagery is an efficient method for constructing 3D virtual reality models. One difficult aspect of creating such models is registering the optical image with the ...

  1. Evaluation of three lidar scanning strategies for turbulence measurements

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Newman, J. F.; Klein, P. M.; Wharton, S.; Sathe, A.; Bonin, T. A.; Chilson, P. B.; Muschinski, A.

    2015-11-24

    Several errors occur when a traditional Doppler-beam swinging (DBS) or velocity–azimuth display (VAD) strategy is used to measure turbulence with a lidar. To mitigate some of these errors, a scanning strategy was recently developed which employs six beam positions to independently estimate the u, v, and w velocity variances and covariances. In order to assess the ability of these different scanning techniques to measure turbulence, a Halo scanning lidar, WindCube v2 pulsed lidar and ZephIR continuous wave lidar were deployed at field sites in Oklahoma and Colorado with collocated sonic anemometers. Results indicate that the six-beam strategy mitigates somemore »of the errors caused by VAD and DBS scans, but the strategy is strongly affected by errors in the variance measured at the different beam positions. The ZephIR and WindCube lidars overestimated horizontal variance values by over 60 % under unstable conditions as a result of variance contamination, where additional variance components contaminate the true value of the variance. A correction method was developed for the WindCube lidar that uses variance calculated from the vertical beam position to reduce variance contamination in the u and v variance components. The correction method reduced WindCube variance estimates by over 20 % at both the Oklahoma and Colorado sites under unstable conditions, when variance contamination is largest. This correction method can be easily applied to other lidars that contain a vertical beam position and is a promising method for accurately estimating turbulence with commercially available lidars.« less

  2. A motor drive control system for the Lidar Polarimeter 

    E-Print Network [OSTI]

    Leung, Waiming

    1977-01-01

    A MOTOR DRIVE CONTROL SYSTEM FOR THE LIDAR POLARIMETER A Thesis by Waiming Leung Submitted to the Graduate College of Texas A/M University in partial fulfillment of the requirement for the degree of MASTER OF SCIENCF, May 1977 Major... Subject: Electrical Engineering A MOTOR DRIVE CONTROL SYSTEM FOR THE LIDAR POLARIMETER A Thesis by Waiming Leung Approved as to style and content by: Chairman o Comm' ee ea o epartment Member Mem er May 1977 ABSTRACT A Motor Drive Control...

  3. ULTRAVIOLET RAMAN SPECTRAL SIGNATURE ACQUISITION: UV RAMAN SPECTRAL FINGERPRINTS.

    SciTech Connect (OSTI)

    SEDLACEK,III, A.J.FINFROCK,C.

    2002-09-01

    As a member of the science-support part of the ITT-lead LISA development program, BNL is tasked with the acquisition of UV Raman spectral fingerprints and associated scattering cross-sections for those chemicals-of-interest to the program's sponsor. In support of this role, the present report contains the first installment of UV Raman spectral fingerprint data on the initial subset of chemicals. Because of the unique nature associated with the acquisition of spectral fingerprints for use in spectral pattern matching algorithms (i.e., CLS, PLS, ANN) great care has been undertaken to maximize the signal-to-noise and to minimize unnecessary spectral subtractions, in an effort to provide the highest quality spectral fingerprints. This report is divided into 4 sections. The first is an Experimental section that outlines how the Raman spectra are performed. This is then followed by a section on Sample Handling. Following this, the spectral fingerprints are presented in the Results section where the data reduction process is outlined. Finally, a Photographs section is included.

  4. LIDAR Wind Speed Measurements of Evolving Wind Fields

    SciTech Connect (OSTI)

    Simley, E.; Pao, L. Y.

    2012-07-01

    Light Detection and Ranging (LIDAR) systems are able to measure the speed of incoming wind before it interacts with a wind turbine rotor. These preview wind measurements can be used in feedforward control systems designed to reduce turbine loads. However, the degree to which such preview-based control techniques can reduce loads by reacting to turbulence depends on how accurately the incoming wind field can be measured. Past studies have assumed Taylor's frozen turbulence hypothesis, which implies that turbulence remains unchanged as it advects downwind at the mean wind speed. With Taylor's hypothesis applied, the only source of wind speed measurement error is distortion caused by the LIDAR. This study introduces wind evolution, characterized by the longitudinal coherence of the wind, to LIDAR measurement simulations to create a more realistic measurement model. A simple model of wind evolution is applied to a frozen wind field used in previous studies to investigate the effects of varying the intensity of wind evolution. LIDAR measurements are also evaluated with a large eddy simulation of a stable boundary layer provided by the National Center for Atmospheric Research. Simulation results show the combined effects of LIDAR errors and wind evolution for realistic turbine-mounted LIDAR measurement scenarios.

  5. Raman Quantum Memory of Photonic Polarised Entanglement

    E-Print Network [OSTI]

    Dong-Sheng Ding; Wei Zhang; Zhi-Yuan Zhou; Shuai Shi; Bao-Sen Shi; Guang-Can Guo

    2014-11-06

    Quantum entanglement of particles is regarded as a fundamental character in quantum information, in which quantum state should be given for whole system instead of independently describing single particle. Constructing quantum memory of photonic entanglement is essential for realizing quantum networks, which had been performed previously by many memory protocols. Of which Raman quantum memory gives advantages in broadband and high-speed properties, resulting in huge potential in quantum network and quantum computation. However, Raman quantum memory of photonic polarised entanglement is a challenge work and still missing. Here, we report two Raman quantum memories based on gas atomic ensembles: 1. Heralded Raman quantum memory of hybrid entanglement of path and polarization of single photon. 2. Raman storage of two-particle photonic polarised entangled state. Our experimental performances of these two different Raman quantum storages of photonic entanglement show a very promising prospective in quantum information science.

  6. Structural Analysis of Southern Dixie Valley using LiDAR and...

    Open Energy Info (EERE)

    and tonal lineaments were used to define possible faults in both the LiDAR and LSA photo data sets.The LiDAR and LSA photo analysis has identified a large number of previously...

  7. Raman spectroscopy in hot compressed hydrogen and nitrogen -...

    Office of Scientific and Technical Information (OSTI)

    Raman spectroscopy in hot compressed hydrogen and nitrogen - implications for the intramolecular potential Citation Details In-Document Search Title: Raman spectroscopy in hot...

  8. THEORETICAL MODELING OF LIDAR RETURN PHENOMENOLOGY FROM SNOW AND ICE SURFACES

    E-Print Network [OSTI]

    Kerekes, John

    THEORETICAL MODELING OF LIDAR RETURN PHENOMENOLOGY FROM SNOW AND ICE SURFACES J. Kerekes, J. Zhang the science of lidar sensing of complex ice and snow surfaces as well as in support of the upcoming ICESat- 2 from snow and ice surfaces. First, the anticipated lidar return characteristics for a sloped non

  9. 6.4 ARCTIC OBSERVATIONS WITH THE UNIVERSITY OF WISCONSIN HIGH SPECTRAL RESOLUTION LIDAR

    E-Print Network [OSTI]

    Eloranta, Edwin W.

    @lidar.ssec.wisc.edu 2 NOAA Earth Systems Research Laboratory, 325 Broadway, Boulder, CO, USA taneil seatainers are joined together as shelter for the lidar, radar, and PAREI instruments. The 35 GHz radar antenna is seen on the near corner of the shelter and the zenith facing lidar window is located

  10. Comparison of Two Independent LIDAR-Based Pitch Control Designs

    SciTech Connect (OSTI)

    Dunne, F.; Schlipf, D.; Pao, L. Y.

    2012-08-01

    Two different lidar-based feedforward controllers have previously been designed for the NREL 5 MW wind turbine model under separate studies. Feedforward controller A uses a finite-impulse-response design, with 5 seconds of preview, and three rotating lidar measurements. Feedforward controller B uses a static-gain design, with the preview time defined by the pitch actuator dynamics, a simulation of a real nacelle-based scanning lidar system, and a lowpass filter defined by the lidar configuration. These controllers are now directly compared under the same lidar configuration, in terms of fatigue load reduction, rotor speed regulation, and power capture. The various differences in design choices are discussed and compared. We also compare frequency plots of individual pitch feedforward and collective pitch feedforward load reductions, and we see that individual pitch feedforward is effective mainly at the once-per-revolution and twice-per-revolution frequencies. We also explain how to determine the required preview time by breaking it down into separate parts, and we then compare it to the expected preview time available.

  11. Noise autocorrelation spectroscopy with coherent Raman scattering

    E-Print Network [OSTI]

    Loss, Daniel

    LETTERS Noise autocorrelation spectroscopy with coherent Raman scattering XIAOJI G. XU, STANISLAV O to noise. Here, we present a new approach to coherent Raman spectroscopy in which high resolution is achieved by means of deliberately introduced noise. The proposed method combines the efficiency

  12. RAMAN SPECTROSCOPY OF GRAPHENE AND RELATED MATERIALS

    E-Print Network [OSTI]

    Chen, Yong P.

    structure of graphene. (b) Graphene is a zero-gap semiconductor. Its 2-D nature leads to a linear dispersionChapter 19 RAMAN SPECTROSCOPY OF GRAPHENE AND RELATED MATERIALS Isaac Childres*a,b , Luis A This chapter is a review of the application of Raman spectroscopy in characterizing the properties of graphene

  13. Multiplex coherent raman spectroscopy detector and method

    DOE Patents [OSTI]

    Chen, Peter; Joyner, Candace C.; Patrick, Sheena T.; Guyer, Dean R.

    2004-06-08

    A multiplex coherent Raman spectrometer (10) and spectroscopy method rapidly detects and identifies individual components of a chemical mixture separated by a separation technique, such as gas chromatography. The spectrometer (10) and method accurately identify a variety of compounds because they produce the entire gas phase vibrational Raman spectrum of the unknown gas. This is accomplished by tilting a Raman cell (20) to produce a high-intensity, backward-stimulated, coherent Raman beam of 683 nm, which drives a degenerate optical parametric oscillator (28) to produce a broadband beam of 1100-1700 nm covering a range of more than 3000 wavenumber. This broadband beam is combined with a narrowband beam of 532 nm having a bandwidth of 0.003 wavenumbers and focused into a heated windowless cell (38) that receives gases separated by a gas chromatograph (40). The Raman radiation scattered from these gases is filtered and sent to a monochromator (50) with multichannel detection.

  14. ARM: ARSCL: multiple outputs from first Clothiaux algorithms on Vaisala or Belfort ceilometers, Micropulse lidar, and MMCR

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Karen Johnson; Michael Jensen

    ARSCL: multiple outputs from first Clothiaux algorithms on Vaisala or Belfort ceilometers, Micropulse lidar, and MMCR

  15. ARM: ARSCL: cloud boundaries from first Clothiaux algorithms on Vaisala or Belfort ceilometers, Micropulse lidar, and MMCR

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Karen Johnson; Michael Jensen

    ARSCL: cloud boundaries from first Clothiaux algorithms on Vaisala or Belfort ceilometers, Micropulse lidar, and MMCR

  16. Imaging doppler lidar for wind turbine wake profiling

    DOE Patents [OSTI]

    Bossert, David J.

    2015-11-19

    An imaging Doppler lidar (IDL) enables the measurement of the velocity distribution of a large volume, in parallel, and at high spatial resolution in the wake of a wind turbine. Because the IDL is non-scanning, it can be orders of magnitude faster than conventional coherent lidar approaches. Scattering can be obtained from naturally occurring aerosol particles. Furthermore, the wind velocity can be measured directly from Doppler shifts of the laser light, so the measurement can be accomplished at large standoff and at wide fields-of-view.

  17. Assessment and Optimization of Lidar Measurement Availability for Wind Turbine Control: Preprint

    SciTech Connect (OSTI)

    Davoust, S.; Jehu, A.; Bouillet, M.; Bardon, M.; Vercherin, B.; Scholbrock, A.; Fleming, P.; Wright, A.

    2014-05-01

    Turbine-mounted lidars provide preview measurements of the incoming wind field. By reducing loads on critical components and increasing the potential power extracted from the wind, the performance of wind turbine controllers can be improved [2]. As a result, integrating a light detection and ranging (lidar) system has the potential to lower the cost of wind energy. This paper presents an evaluation of turbine-mounted lidar availability. Availability is a metric which measures the proportion of time the lidar is producing controller-usable data, and is essential when a wind turbine controller relies on a lidar. To accomplish this, researchers from Avent Lidar Technology and the National Renewable Energy Laboratory first assessed and modeled the effect of extreme atmospheric events. This shows how a multirange lidar delivers measurements for a wide variety of conditions. Second, by using a theoretical approach and conducting an analysis of field feedback, we investigated the effects of the lidar setup on the wind turbine. This helps determine the optimal lidar mounting position at the back of the nacelle, and establishes a relationship between availability, turbine rpm, and lidar sampling time. Lastly, we considered the role of the wind field reconstruction strategies and the turbine controller on the definition and performance of a lidar's measurement availability.

  18. Inelastic neutron and low-frequency Raman scattering in a niobium-phosphate glass for Raman gain applications

    E-Print Network [OSTI]

    Schirmacher, Walter

    Inelastic neutron and low-frequency Raman scattering in a niobium-phosphate glass for Raman gain: Raman scattering; Neutron scattering; Raman gain; Boson peak We present measurements of the vibrational, extracted from specific-heat or neutron scattering measurements [7,8]. Only very recently two of the present

  19. Automatic Construction of Building Footprints from Airborne LIDAR Data

    E-Print Network [OSTI]

    Chen, Shu-Ching

    1 Automatic Construction of Building Footprints from Airborne LIDAR Data Keqi Zhang, Jianhua Yan. INTRODUCTION BUILDING footprints are one of the fundamental GIS data components that can be used to estimate, and estimation of building base elevation for flood insurance [2]. In addition, footprint data in combination

  20. Airborne lidar detection and characterization of internal waves in a

    E-Print Network [OSTI]

    Shaw, Joseph A.

    on the strength of the wind. This tends to create a layer of less dense water on top of the more dense water below of water with lower density at the surface. This layer is typically mixed with the water below. The airborne lidar detected a thin plankton layer at the bottom of the upper layer of the water

  1. Lidar fluorosensing of mineral oil spills on the sea surface

    E-Print Network [OSTI]

    Oldenburg, Carl von Ossietzky Universität

    be discriminated from heavy fuel, and from less harmful substances like fish oil or vegetable oil, Fig. 3, whichLidar fluorosensing of mineral oil spills on the sea surface Theo Hengstermann and Rainer Reuter Airborne .fluorosensor measurements over maritime oil spills show that this method enables a sensitive

  2. Wind velocity measurements using a pulsed LIDAR system: first results

    E-Print Network [OSTI]

    Peinke, Joachim

    , M K¨uhn3 and J Peinke4 1,4 ForWind Center for Wind Energy Research, University of Oldenburg, Germany 2,3 Endowed Chair of Wind Energy, University of Stuttgart, Germany E-mail: 1 matthias relevance for wind energy utilization. Different technologies are in use in this field, among them LIDAR

  3. Research Article Application of Short-Range LIDAR in

    E-Print Network [OSTI]

    Tang, Wenbo

    a series of meteorological instruments, including long-range LIDAR (light detection and ranging) systems Island of complex terrain to the south. The Lantau Island is composed of rows of northeast- southwest are brought about by strong winds across the Lantau Island to the south of the airport, including the strong

  4. Noninvasive glucose sensing by transcutaneous Raman spectroscopy

    E-Print Network [OSTI]

    Shih, Wei-Chuan

    We present the development of a transcutaneous Raman spectroscopy system and analysis algorithm for noninvasive glucose sensing. The instrument and algorithm were tested in a preclinical study in which a dog model was used. ...

  5. Tunable infrared source employing Raman mixing

    DOE Patents [OSTI]

    Byer, Robert L. (Stanford, CA); Herbst, Richard L. (Menlo Park, CA)

    1980-01-01

    A tunable source of infrared radiation is obtained by irradiating an assemblage of Raman active gaseous atoms or molecules with a high intensity pumping beam of coherent radiation at a pump frequency .omega..sub.p to stimulate the generation of Stokes wave energy at a Stokes frequency .omega..sub.s and to stimulate the Raman resonant mode at the Raman mode frequency .omega..sub.R within the irradiated assemblage where the pump frequency .omega..sub.p minus the Stokes frequency .omega..sub.s is equal to the Raman mode frequency .omega..sub.R. The stimulated assemblage is irradiated with a tunable source of coherent radiation at a frequency .omega..sub.i to generate the output infrared radiation of the frequency .omega..sub.0 which is related to the Raman mode frequency .omega..sub.R and the input wave .omega..sub.i by the relation .omega..sub.0 =.omega..sub.i .+-..omega..sub.R. In one embodiment the interaction between the pump wave energy .omega..sub.p and the tunable input wave energy .omega..sub.i is collinear and the ratio of the phase velocity mismatch factor .DELTA.k to the electric field exponential gain coefficient T is within the range of 0.1 to 5. In another embodiment the pump wave energy .omega..sub.p and the tunable input wave energy .omega..sub.i have velocity vectors k.sub.p and k.sub.i which cross at an angle to each other to compensate for phase velocity mismatches in the medium. In another embodiment, the Stokes wave energy .omega..sub.s is generated by pump energy .omega..sub.p in a first Raman cell and .omega..sub.s, .omega..sub.i and .omega..sub.p are combined in a second Raman mixing cell to produce the output at .omega..sub.i.

  6. Assessment and Optimization of Lidar Measurement Availability for Wind Turbine Control (Poster)

    SciTech Connect (OSTI)

    Scholbrock, F. A.; Fleming, P.; Wright, A.; Davoust, S.; Jehu, A.; Bouillet, M.; Bardon M.; Vercherin, B.

    2014-02-01

    Integrating Lidar to improve wind turbine controls is a potential breakthrough for reducing the cost of wind energy. By providing undisturbed wind measurements up to 400m in front of the rotor, Lidar may provide an accurate update of the turbine inflow with a preview time of several seconds. Focusing on loads, several studies have evaluated potential reductions using integrated Lidar, either by simulation or full scale field testing.

  7. Seasonal and optical characterisation of cirrus clouds over Indian sub-continent using LIDAR

    SciTech Connect (OSTI)

    Jayeshlal, G. S., E-mail: drssatyanarayana.malladi@gmail.com; Satyanarayana, Malladi, E-mail: drssatyanarayana.malladi@gmail.com; Dhaman, Reji K., E-mail: drssatyanarayana.malladi@gmail.com; Motty, G. S., E-mail: drssatyanarayana.malladi@gmail.com [Department of Optoelectronics, University of Kerala, Karyavattom, Trivandrum-695 581, Kerala (India)

    2014-10-15

    Light Detection and Ranging (LIDAR) is an important remote sensing technique to study about the cirrus clouds. The subject of cirrus clouds and related climate is challenging one. The received scattered signal from Lidar contains information on the physical and optical properties of cirrus clouds. The Lidar profile of the cirrus cloud provides information on the optical characteristics like depolarisation ratio, lidar ratio and optical depth, which give knowledge about possible phase, structure and orientation of cloud particle that affect the radiative budgeting of cirrus clouds. The findings from the study are subjected to generate inputs for better climatic modelling.

  8. Ultraviolet Resonant Raman Enhancements in the Detection of Explosives

    SciTech Connect (OSTI)

    Short, B J; Carter, J C; Gunter, D; Hovland, P; Jagode, H; Karavanic, K; Marin, G; Mellor-Crummey, J; Moore, S; Norris, B; Oliker, L; Olschanowsky, C; Roth, P C; Schulz, M; Shende, S; Snavely, A; Spear, W

    2009-06-03

    Raman-based spectroscopy is potentially militarily useful for standoff detection of high explosives. Normal (non-resonance) and resonance Raman spectroscopies are both light scattering techniques that use a laser to measure the vibrational spectrum of a sample. In resonance Raman, the laser is tuned to match the wavelength of a strong electronic absorbance in the molecule of interest, whereas, in normal Raman the laser is not tuned to any strong electronic absorbance bands. The selection of appropriate excitation wavelengths in resonance Raman can result in a dramatic increase in the Raman scattering efficiency of select band(s) associated with the electronic transition. Other than the excitation wavelength, however, resonance Raman is performed experimentally the same as normal Raman. In these studies, normal and resonance Raman spectral signatures of select solid high explosive (HE) samples and explosive precursors were collected at 785 nm, 244 nm and 229 nm. Solutions of PETN, TNT, and explosive precursors (DNT & PNT) in acetonitrile solvent as an internal Raman standard were quantitatively evaluated using ultraviolet resonance Raman (UVRR) microscopy and normal Raman spectroscopy as a function of power and select excitation wavelengths. Use of an internal standard allowed resonance enhancements to be estimated at 229 nm and 244 nm. Investigations demonstrated that UVRR provided {approx}2000-fold enhancement at 244 nm and {approx}800-fold improvement at 229 nm while PETN showed a maximum of {approx}25-fold at 244 nm and {approx}190-fold enhancement at 229 nm solely from resonance effects when compared to normal Raman measurements. In addition to the observed resonance enhancements, additional Raman signal enhancements are obtained with ultraviolet excitation (i.e., Raman scattering scales as !4 for measurements based on scattered photons). A model, based partly on the resonance Raman enhancement results for HE solutions, is presented for estimating Raman enhancements for solid HE samples.

  9. On-Chip Diamond Raman Laser

    E-Print Network [OSTI]

    Latawiec, Pawel; Burek, Michael J; Hausmann, Birgit J M; Bulu, Irfan; Loncar, Marko

    2015-01-01

    Synthetic single-crystal diamond has recently emerged as a promising platform for Raman lasers at exotic wavelengths due to its giant Raman shift, large transparency window and excellent thermal properties yielding a greatly enhanced figure-of-merit compared to conventional materials. To date, diamond Raman lasers have been realized using bulk plates placed inside macroscopic cavities, requiring careful alignment and resulting in high threshold powers (~W-kW). Here we demonstrate an on-chip Raman laser based on fully-integrated, high quality-factor, diamond racetrack micro-resonators embedded in silica. Pumping at telecom wavelengths, we show Stokes output discretely tunable over a ~100nm bandwidth around 2-{\\mu}m with output powers >250 {\\mu}W, extending the functionality of diamond Raman lasers to an interesting wavelength range at the edge of the mid-infrared spectrum. Continuous-wave operation with only ~85 mW pump threshold power in the feeding waveguide is demonstrated along with continuous, mode-hop-fr...

  10. DOE/SC-ARM/TR-100 Raman Lidar Profiles Best Estimate Value-Added Product Technical Report

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration would like submit theCovalent Bonding Low-Cost2 DOE HQSiteo n n e v i2 ARM Climate1623375 The780

  11. Lidar arc scan uncertainty reduction through scanning geometry optimization

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Wang, H.; Barthelmie, R. J.; Pryor, S. C.; Brown, G.

    2015-10-07

    Doppler lidars are frequently operated in a mode referred to as arc scans, wherein the lidar beam scans across a sector with a fixed elevation angle and the resulting measurements are used to derive an estimate of the n minute horizontal mean wind velocity (speed and direction). Previous studies have shown that the uncertainty in the measured wind speed originates from turbulent wind fluctuations and depends on the scan geometry (the arc span and the arc orientation). This paper is designed to provide guidance on optimal scan geometries for two key applications in the wind energy industry: wind turbine powermore »performance analysis and annual energy production. We present a quantitative analysis of the retrieved wind speed uncertainty derived using a theoretical model with the assumption of isotropic and frozen turbulence, and observations from three sites that are onshore with flat terrain, onshore with complex terrain and offshore, respectively. The results from both the theoretical model and observations show that the uncertainty is scaled with the turbulence intensity such that the relative standard error on the 10 min mean wind speed is about 30 % of the turbulence intensity. The uncertainty in both retrieved wind speeds and derived wind energy production estimates can be reduced by aligning lidar beams with the dominant wind direction, increasing the arc span and lowering the number of beams per arc scan. Large arc spans should be used at sites with high turbulence intensity and/or large wind direction variation when arc scans are used for wind resource assessment.« less

  12. Multistaged stokes injected Raman capillary waveguide amplifier

    DOE Patents [OSTI]

    Kurnit, Norman A. (Santa Fe, NM)

    1980-01-01

    A multistaged Stokes injected Raman capillary waveguide amplifier for providing a high gain Stokes output signal. The amplifier uses a plurality of optically coupled capillary waveguide amplifiers and one or more regenerative amplifiers to increase Stokes gain to a level sufficient for power amplification. Power amplification is provided by a multifocused Raman gain cell or a large diameter capillary waveguide. An external source of CO.sub.2 laser radiation can be injected into each of the capillary waveguide amplifier stages to increase Raman gain. Devices for injecting external sources of CO.sub.2 radiation include: dichroic mirrors, prisms, gratings and Ge Brewster plates. Alternatively, the CO.sub.2 input radiation to the first stage can be coupled and amplified between successive stages.

  13. Raman spectroscopy of complex defined media: biopharmaceutical applications

    E-Print Network [OSTI]

    Ram, Rajeev J.

    , grown in shake flasks in batch fermentation mode, using Raman spectroscopy and explicit model glutamine, glutamate, glucose, la

  14. Raman Shift (cm-1 1500 2000 2500 3000 3500

    E-Print Network [OSTI]

    1 Raman Shift (cm-1 ) 1500 2000 2500 3000 3500 RamanIntensity(a.u.) 0 2000 4000 6000 8000 Water - Anisotropic 0.10x HBr - Anisotropic 0.10x HI - Anisotropic Raman Shift (cm-1 ) 1500 2000 2500 3000 3500 RamanIntensity(a.u.) 0 2000 4000 6000 8000 Water - Isotropic 0.015x HCl - Isotropic 0.015x HBr - Isotropic 0.015x HI

  15. Window Transmission Monitoring and Cleaning Schemes used with the LIDAR Thomson Scattering Diagnostic on the JET Tokamak

    E-Print Network [OSTI]

    Window Transmission Monitoring and Cleaning Schemes used with the LIDAR Thomson Scattering Diagnostic on the JET Tokamak

  16. ARM: ARSCL: cloud base height from first Clothiaux algorithms on Vaisala or Belfort ceilometers, Micropulse lidar, and MMCR

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Karen Johnson; Michael Jensen

    ARSCL: cloud base height from first Clothiaux algorithms on Vaisala or Belfort ceilometers, Micropulse lidar, and MMCR

  17. Special Section Guest Editorial Coherent Raman Imaging Techniques and Biomedical

    E-Print Network [OSTI]

    Potma, Eric Olaf

    Special Section Guest Editorial Coherent Raman Imaging Techniques and Biomedical Applications. The combination of high resolution and molecular contrast has moved Raman techniques into the biomedical spotlight on biomedical imag- ing. The spontaneous Raman interaction is weak, yielding insufficient photons for fast

  18. Raman subrecoil spectroscopy of cold cesium atoms

    E-Print Network [OSTI]

    J. Ringot; P. Szriftgiser; J. C. Garreau

    2001-07-28

    We describe and characterize a setup for subrecoil stimulated Raman spectroscopy of cold cesium atoms. We study in particular the performances of a method designed to active control and stabilization of the magnetic fields across a cold-atom cloud inside a small vacuum cell. The performance of the setup is monitored by {\\em copropagative-beam} stimulated Raman spectroscopy of a cold cesium sample. The root mean-square value of the residual magnetic field is 300 $\\mu G$, with a compensation bandwidth of 500 Hz. The shape of the observed spectra is theoretically interpreted and compares very well to numerically generated spectra.

  19. Turbine Reliability and Operability Optimization through the use of Direct Detection Lidar Final Technical Report

    SciTech Connect (OSTI)

    Johnson, David K; Lewis, Matthew J; Pavlich, Jane C; Wright, Alan D; Johnson, Kathryn E; Pace, Andrew M

    2013-02-01

    The goal of this Department of Energy (DOE) project is to increase wind turbine efficiency and reliability with the use of a Light Detection and Ranging (LIDAR) system. The LIDAR provides wind speed and direction data that can be used to help mitigate the fatigue stress on the turbine blades and internal components caused by wind gusts, sub-optimal pointing and reactionary speed or RPM changes. This effort will have a significant impact on the operation and maintenance costs of turbines across the industry. During the course of the project, Michigan Aerospace Corporation (MAC) modified and tested a prototype direct detection wind LIDAR instrument; the resulting LIDAR design considered all aspects of wind turbine LIDAR operation from mounting, assembly, and environmental operating conditions to laser safety. Additionally, in co-operation with our partners, the National Renewable Energy Lab and the Colorado School of Mines, progress was made in LIDAR performance modeling as well as LIDAR feed forward control system modeling and simulation. The results of this investigation showed that using LIDAR measurements to change between baseline and extreme event controllers in a switching architecture can reduce damage equivalent loads on blades and tower, and produce higher mean power output due to fewer overspeed events. This DOE project has led to continued venture capital investment and engagement with leading turbine OEMs, wind farm developers, and wind farm owner/operators.

  20. AUTOMATED MODELING OF 3D BUILDING ROOFS USING IMAGE AND LIDAR DATA

    E-Print Network [OSTI]

    Schindler, Konrad

    AUTOMATED MODELING OF 3D BUILDING ROOFS USING IMAGE AND LIDAR DATA N. Demir* , E. Baltsavias, Detection, 3D Modelling ABSTRACT: In this work, an automated approach for 3D building roof modelling of accurate and complete 3D building models with high degree of automation. Aerial images and LiDAR data

  1. BUILDING ROOF SEGMENTATION AND RECONSTRUCTION FROM LIDAR POINT CLOUDS USING CLUSTERING TECHNIQUES

    E-Print Network [OSTI]

    Shan, Jie

    BUILDING ROOF SEGMENTATION AND RECONSTRUCTION FROM LIDAR POINT CLOUDS USING CLUSTERING TECHNIQUES presents an approach to creating a polyhedral model of building roof from LiDAR point clouds using. The normal vectors are then clustered together to determine the principal directions of the roof planes

  2. 3-D tomographic imaging of ocean mines from real and simulated lidar returns

    E-Print Network [OSTI]

    Singer, Andrew C

    3-D tomographic imaging of ocean mines from real and simulated lidar returns Nail C¸adalli, Peter J of underwater objects, where the trans- mitted laser beam can penetrate the air-water interface and illuminate by using an accurate statistical model that incorporates multiple scattering. Keywords: lidar, ocean optics

  3. Coherent anti-Stokes Raman Scattering (CARS)

    E-Print Network [OSTI]

    Greenaway, Alan

    Coherent anti-Stokes Raman Scattering (CARS) For the study of biofilms Alexander Mc Vey1, Nils.f.mcvey@ed.ac.uk Polystyrene beads of diameter 2µm as imaged by the CARS system at COSMIC, The University of Edinburgh #12;Introduction Outline of CARS CARS set-up Results ­ Pushing the limits Results ­ Imaging E. coli Where do we go

  4. Stokes injected Raman capillary waveguide amplifier

    DOE Patents [OSTI]

    Kurnit, Norman A. (Santa Fe, NM)

    1980-01-01

    A device for producing stimulated Raman scattering of CO.sub.2 laser radiation by rotational states in a diatomic molecular gas utilizing a Stokes injection signal. The system utilizes a cryogenically cooled waveguide for extending focal interaction length. The waveguide, in conjunction with the Stokes injection signal, reduces required power density of the CO.sub.2 radiation below the breakdown threshold for the diatomic molecular gas. A Fresnel rhomb is employed to circularly polarize the Stokes injection signal and CO.sub.2 laser radiation in opposite circular directions. The device can be employed either as a regenerative oscillator utilizing optical cavity mirrors or as a single pass amplifier. Additionally, a plurality of Raman gain cells can be staged to increase output power magnitude. Also, in the regenerative oscillator embodiment, the Raman gain cell cavity length and CO.sub.2 cavity length can be matched to provide synchronism between mode locked CO.sub.2 pulses and pulses produced within the Raman gain cell.

  5. Raman laser with controllable suppression of parasitics

    DOE Patents [OSTI]

    George, E. Victor (Livermore, CA)

    1986-01-01

    Method and apparatus for switching energy out of a Raman laser optical cavity. Coherent radiation at both the pump and first Stokes wave frequencies are introduced into the optical cavity from the same direction, and a second Stokes wave is utilized to switch the energy out of the cavity.

  6. ARM - Field Campaign - Lidar support for ICECAPS at Summit, Greenland

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach HomeA Better Anode Design to Improve4AJ01)govCampaignsFIRE-Arctic- HemisphericCloudsgovCampaignsLidar

  7. Lidar Inter-Comparison Exercise Final Campaign Report A Protat

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach Home Room NewsInformationJesse Bergkamp GraduateResidentialLensless Imaging ofLibSciTeaming UpLidar

  8. Raman-based system for DNA sequencing-mapping and other separations

    DOE Patents [OSTI]

    Vo-Dinh, T.

    1994-04-26

    DNA sequencing and mapping are performed by using a Raman spectrometer with a surface enhanced Raman scattering (SERS) substrate to enhance the Raman signal. A SERS label is attached to a DNA fragment and then analyzed with the Raman spectrometer to identify the DNA fragment according to characteristics of the Raman spectrum generated. 11 figures.

  9. Raman spectroscopic investigations of hydrothermal solutions

    SciTech Connect (OSTI)

    Yang, M.M.

    1988-01-01

    There is still very little information about the stoichiometries, structures and stabilities of metal complexes at high temperatures and pressures. Raman spectroscopy is ideally suited to probe and study concentrated electrolyte solutions at the molecular level. This thesis includes the design and construction of a Raman cell operable up to 300C and 15MPa. In order to obtain quantitative thermodynamic information from Raman spectroscopic measurements, a chemically inert internal standard must be used. Perchlorate is commonly used for this purpose at low temperatures, but it may be unstable at high temperatures and its explosive properties make it undesirable. A new preferred internal standard; trifluoromethanesulfonic acid is introduced and its spectra p to 300C discussed. The use of this compound as a high temperature internal standard enabled stepwise stability constants of zinc-bromo complexes to be determined. Although bromide is not an important ligand in geologic systems, its chemical similarity to chloride can provide insights into the study of zinc-chloro species which do not have very informative Raman spectra. The importance of organic ligands in geologic settings such as the Mississippi-Valley Type Pb-Zn sulfide deposits is now being realized. Chapter four presents the first high temperature spectroscopic measurements of lead and zinc acetate aqueous solutions. Not only do these studies verify the stability of lead and zinc acetate complexes up to 250 C but they also show that the type of complex formed is a function of pH, metal-ligand ratio and temperature, thus having important implications for zoning of Pb-Zn sulfide deposits.

  10. Complex-optical-field lidar system for range and vector velocity measurement

    E-Print Network [OSTI]

    Gao, Shuang; Sullivan, Maurice O.; Hui, Rongqing

    2012-11-01

    lidar system based on the measurement of complex optical field is demonstrated for the first time. An electro-optic in- phase/quadrature (I/Q) modulator is used in the lidar transmitter to realize carrier-suppressed complex optical field modulation...-modulated continuous-wave lidar using I/Q modulator for simplified heterodyne detection,” Opt. Lett. 37(11), 2022–2024 (2012). 11. Y. Zhang, M. O’Sullivan, and R. Hui, “Digital subcarrier multiplexing for flexible spectral allocation in optical transport network...

  11. Quasi 2D Materials: Raman Nanometrology and Thermal Management Applications

    E-Print Network [OSTI]

    Shahil, Khan Mohammad Farhan

    2012-01-01

    heating Electrical Theory: MD Theory: MD Raman optothermalElectrical self- heating Electrical Theory:VFF,BTE Theory:Thermocouples Thermocouples Theory: BTE Electrical self-

  12. Combined Quantum Chemical/Raman Spectroscopic Analyses of Li...

    Office of Scientific and Technical Information (OSTI)

    ChemicalRaman Spectroscopic Analyses of Li+ Cation Solvation: Cyclic Carbonate Solvents - Ethylene Carbonate and Propylene Earbonate Citation Details In-Document Search...

  13. Fully automatic calibration of LIDAR and video streams from a vehicle

    E-Print Network [OSTI]

    Bileschi, Stanley M.

    This work describes a fully automatic technique to calibrate a geometric mapping between lidar and video feeds on a mobile ground-based platform. This data association is a crucial first step for any multi-modal scene ...

  14. Statistical methods for 2D-3D registration of optical and LIDAR images

    E-Print Network [OSTI]

    Mastin, Dana Andrew

    2009-01-01

    Fusion of 3D laser radar (LIDAR) imagery and aerial optical imagery is an efficient method for constructing 3D virtual reality models. One difficult aspect of creating such models is registering the optical image with the ...

  15. USING LIDAR TO MEASURE PERFLUOROCARBON TRACERS FOR THE VERIFICATION AND MONITORING

    E-Print Network [OSTI]

    and pilot-scale indoor experiments using an a continuous wave, line-tunable infrared CO2 laser were used region Using a pilot-scale lidar system in a 40 m indoor hallway air concentrations of PMCH were

  16. Simulation of Lidar Return Signals Associated with Water Clouds 

    E-Print Network [OSTI]

    Lu, Jianxu

    2010-01-14

    depolarization is not shown and the sensitivity studies on the empirical relationship are not very clear. Thus more details are needed for further research. This thesis will present another way to derive the multiple-scattering lidar equa- tion reported by Rakovi....0?m when 10 million photons are sampled. The idea is from Winker and Poole [9]. 38 0 0.2 0.4 0.6 0.8 1 0 0.1 0.2 0.3 0.4 0.5 0.6 Ef fec tiv eM ult ipl eS cat ter ing Fa cto r?? Integrated Volume Depolarization Ratio ?acc 3?m4?m 6?m8?m 15?m20?m (1??acc...

  17. Raman beam combining for laser brightness enhancement

    DOE Patents [OSTI]

    Dawson, Jay W; Allen, Grahan S; Pax, Paul H; Heebner, John E; Sridharan, Arun K; Rubenchik, Alexander M; Barty, Christopher B.J

    2015-11-05

    An optical source capable of enhanced scaling of pulse energy and brightness utilizes an ensemble of single-aperture fiber lasers as pump sources, with each such fiber laser operating at acceptable pulse energy levels. Beam combining involves stimulated Raman scattering using a Stokes' shifted seed beam, the latter of which is optimized in terms of its temporal and spectral properties. Beams from fiber lasers can thus be combined to attain pulses with peak energies in excess of the fiber laser self-focusing limit of 4 MW while retaining the advantages of a fiber laser system of high average power with good beam quality.

  18. Raman beam combining for laser brightness enhancement

    DOE Patents [OSTI]

    Dawson, Jay W.; Allen, Graham S.; Pax, Paul H.; Heebner, John E.; Sridharan, Arun K.; Rubenchik, Alexander M.; Barty, Chrisopher B. J.

    2015-10-27

    An optical source capable of enhanced scaling of pulse energy and brightness utilizes an ensemble of single-aperture fiber lasers as pump sources, with each such fiber laser operating at acceptable pulse energy levels. Beam combining involves stimulated Raman scattering using a Stokes' shifted seed beam, the latter of which is optimized in terms of its temporal and spectral properties. Beams from fiber lasers can thus be combined to attain pulses with peak energies in excess of the fiber laser self-focusing limit of 4 MW while retaining the advantages of a fiber laser system of high average power with good beam quality.

  19. Optical pumping via incoherent Raman transitions

    E-Print Network [OSTI]

    A. D. Boozer; R. Miller; T. E. Northup; A. Boca; H. J. Kimble

    2007-10-04

    A new optical pumping scheme is presented that uses incoherent Raman transitions to prepare a trapped Cesium atom in a specific Zeeman state within the 6S_{1/2}, F=3 hyperfine manifold. An important advantage of this scheme over existing optical pumping schemes is that the atom can be prepared in any of the F=3 Zeeman states. We demonstrate the scheme in the context of cavity quantum electrodynamics, but the technique is equally applicable to a wide variety of atomic systems with hyperfine ground-state structure.

  20. Quantum-entanglement-initiated super Raman scattering

    SciTech Connect (OSTI)

    Agarwal, G. S. [Department of Physics, Oklahoma State University, Stillwater, Oklahoma 74078 (United States)

    2011-02-15

    It has now been possible to prepare a chain of ions in an entangled state and thus the question arises: How will the optical properties of a chain of entangled ions differ from say a chain of independent particles? We investigate nonlinear optical processes in such chains. Since light scattering is quite a versatile technique to probe matter, we explicitly demonstrate the possibility of entanglement-produced super Raman scattering. Our results suggest the possibility of similar enhancement factors in other nonlinear processes like four-wave mixing.

  1. Heterodyne coherent anti-Stokes Raman scattering (CARS) imaging

    E-Print Network [OSTI]

    Potma, Eric Olaf

    Heterodyne coherent anti-Stokes Raman scattering (CARS) imaging Eric O. Potma,* Conor L. Evans with heterodyne co- herent anti-Stokes Raman scattering (CARS) interferometric microscopy. This technique that is linear in the concentration of vibrational modes. We show that heterodyne CARS microscopy permits

  2. Hydrogen Raman shifts in carbon nanotubes from molecular dynamics simulation

    E-Print Network [OSTI]

    Hydrogen Raman shifts in carbon nanotubes from molecular dynamics simulation S.J.V. Frankland *, D hydrogen in individual single-shell carbon nanotubes and nanotube ropes using a semiclassical model. The calculations predict that isolated hydrogen molecules inside of nanotubes have a Raman frequency that increases

  3. Tides in the mesopause region over Fort Collins, Colorado (41N, 105W) based on lidar temperature observations

    E-Print Network [OSTI]

    - teristics of the westward traveling solar tidal waves in the mesopause region, which can impact thermal hopefully stimulate future tidal studies with lidar temperature, and zonal and meridional wind observations: tides, mesopause region, lidar temperature, midlatitude 1. Introduction [2] Atmospheric solar tides

  4. A comparison of cloud top heights computed from airborne lidar and MAS radiance data using CO2 slicing

    E-Print Network [OSTI]

    Baum, Bryan A.

    A comparison of cloud top heights computed from airborne lidar and MAS radiance data using CO2]. Other studies have compared CO2- slicing cloud heights with those computed from lidar data [Smith in assessing the accuracy of the CO2-slicing cloud height algorithm. Infrared measurements of upwelling

  5. Remote control and telescope auto-alignment system for multiangle LIDAR under development at CEILAP, Argentina

    E-Print Network [OSTI]

    Pallotta, Juan; Otero, Lidia; Chouza, Fernando; Raul, Delia; Gonzalez, Francisco; Etchegoyen, Alberto; Quel, Eduardo

    2013-01-01

    At CEILAP (CITEDEF-CONICET), a multiangle LIDAR is under development to monitor aerosol extinction coefficients in the frame of the CTA (Cherenkov Telescope Array) Project. This is an initiative to build the next generation of ground-based instruments to collect very high energy gamma-ray radiation (>10 GeV). The atmospheric conditions are very important for CTA observations, and LIDARs play an important role in the measurement of the aerosol optical depth at any direction. The LIDAR being developed at CEILAP was conceived to operate in harsh environmental conditions during the shifts, and these working conditions may produce misalignments. To minimize these effects, the telescopes comprising the reception unit are controlled by a self-alignment system. This paper describes the self-alignment method and hardware automation.

  6. Development of coherent Raman measurements of temperature in condensed phases

    SciTech Connect (OSTI)

    Mcgrane, Shawn D; Dang, Nhan C; Bolme, Cindy A; Moore, David S

    2010-12-08

    We report theoretical considerations and preliminary data on various forms of coherent Raman spectroscopy that have been considered as candidates for measurement of temperature in condensed phase experiments with picosecond time resolution. Due to the inherent broadness and congestion of vibrational features in condensed phase solids, particularly at high temperatures and pressures, only approaches that rely on the ratio of anti-Stokes to Stokes spectral features are considered. Methods that rely on resolution of vibrational progressions, calibration of frequency shifts with temperature and pressure in reference experiments, or detailed comparison to calculation are inappropriate or impossible for our applications. In particular, we consider femtosecond stimulated Raman spectroscopy (FSRS), femtosecond/picosecond hybrid coherent Raman spectroscopy (multiplex CARS), and optical heterodyne detected femtosecond Raman induced Kerr Effect spectroscopy (OHD-FRIKES). We show that only FSRS has the ability to measure temperature via an anti-Stokes to Stokes ratio of peaks.

  7. Angular output of hollow, metal-lined, waveguide Raman sensors

    SciTech Connect (OSTI)

    Biedrzycki, Stephen; Buric, Michael P.; Falk, Joel; Woodruff, Steven D.

    2012-04-20

    Hollow, metal-lined waveguides used as gas sensors based on spontaneous Raman scattering are capable of large angular collection. The collection of light from a large solid angle implies the collection of a large number of waveguide modes. An accurate estimation of the propagation losses for these modes is required to predict the total collected Raman power. We report a theory/experimental comparison of the Raman power collected as a function of the solid angle and waveguide length. New theoretical observations are compared with previous theory appropriate only for low-order modes. A cutback experiment is demonstrated to verify the validity of either theory. The angular distribution of Raman light is measured using aluminum and silver-lined waveguides of varying lengths.

  8. Robust Ramsey sequences with Raman adiabatic rapid passage

    E-Print Network [OSTI]

    Kotru, Krish

    We present a method for robust timekeeping in which alkali-metal atoms are interrogated in a Ramsey sequence based on stimulated Raman transitions with optical photons. To suppress systematic effects introduced by differential ...

  9. Quantitative biological Raman spectroscopy for non-invasive blood analysis

    E-Print Network [OSTI]

    Shih, Wei-Chuan

    2007-01-01

    The long term goal of this project is the measurement of clinically-relevant analytes in the blood tissue matrix of human subjects using near-infrared Raman spectroscopy, with the shorter term research directed towards ...

  10. Surface enhanced Raman spectroscopy on a flat graphene surface

    E-Print Network [OSTI]

    Xu, Weigao

    Surface enhanced Raman spectroscopy (SERS) is an attractive analytical technique, which enables single-molecule sensitive detection and provides its special chemical fingerprints. During the past decades, researchers have ...

  11. Detection of integrins using surface enhanced raman spectroscopy 

    E-Print Network [OSTI]

    Gant, Virgil Alexander

    2005-08-29

    changes of integrins on the surface of a cell maybe possible by developing a combined device such as an atomic force microscope (AFM) and surface enhanced Raman spectroscopy (SERS) system. However, the focus of this research is to first determine...

  12. Surface-enhanced Raman scattering (SERS) dosimeter and probe

    DOE Patents [OSTI]

    Vo-Dinh, T.

    1995-03-21

    A dosimeter and probe for measuring exposure to chemical and biological compounds is disclosed. The dosimeter or probe includes a collector which may be analyzed by surface-enhanced Raman spectroscopy. The collector comprises a surface-enhanced Raman scattering-active material having a coating applied thereto to improve the adsorption properties of the collector. The collector may also be used in automated sequential devices, in probe array devices. 10 figures.

  13. Surface-enhanced Raman scattering (SERS) dosimeter and probe

    DOE Patents [OSTI]

    Vo-Dinh, Tuan (Knoxville, TN)

    1995-01-01

    A dosimeter and probe for measuring exposure to chemical and biological compounds is disclosed. The dosimeter or probe includes a collector which may be analyzed by surface-enhanced Raman spectroscopy. The collector comprises a surface-enhanced Raman scattering-active material having a coating applied thereto to improve the adsorption properties of the collector. The collector may also be used in automated sequential devises, in probe array devices.

  14. Cirrus cloud-temperature interactions over a tropical station, Gadanki from lidar and satellite observations

    SciTech Connect (OSTI)

    S, Motty G, E-mail: mottygs@gmail.com; Satyanarayana, M., E-mail: mottygs@gmail.com; Krishnakumar, V., E-mail: mottygs@gmail.com; Dhaman, Reji k., E-mail: mottygs@gmail.com [Department of Optoelectronics, University of Kerala, Kariavattom, Trivandrum-695 581, Kerala (India)

    2014-10-15

    The cirrus clouds play an important role in the radiation budget of the earth's atmospheric system and are important to characterize their vertical structure and optical properties. LIDAR measurements are obtained from the tropical station Gadanki (13.5{sup 0} N, 79.2{sup 0} E), India, and meteorological indicators derived from Radiosonde data. Most of the cirrus clouds are observed near to the tropopause, which substantiates the strength of the tropical convective processes. The height and temperature dependencies of cloud height, optical depth, and depolarization ratio were investigated. Cirrus observations made using CALIPSO satellite are compared with lidar data for systematic statistical study of cirrus climatology.

  15. Master Thesis: Dual-Doppler technique applied to scanning lidars for the characterization of

    E-Print Network [OSTI]

    Peinke, Joachim

    -lidar system was developed and installed at the offshore wind farm "alpha ventus". This system includes three and wind turbine wakes in large wind farms offshore. Wind Energy, 12(5):431­444, 2009. [2] Brian Hirth, D of multiple wakes in a wind farm M. van Dooren Supervisors: D. Trabucchi, K. S. Hansen University

  16. Estimation of tropical forest structural characteristics using large-footprint lidar

    E-Print Network [OSTI]

    Weishampel, John F.

    Estimation of tropical forest structural characteristics using large-footprint lidar Jason B in identifying the amount of carbon in terrestrial vegetation pools and is central to global carbon cycle studies. Although current remote sensing techniques recover such tropical forest structure poorly, new large-footprint

  17. Adjusting lidar-derived digital terrain models in coastal marshes based on estimated aboveground biomass density

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Medeiros, Stephen; Hagen, Scott; Weishampel, John; Angelo, James

    2015-03-25

    Digital elevation models (DEMs) derived from airborne lidar are traditionally unreliable in coastal salt marshes due to the inability of the laser to penetrate the dense grasses and reach the underlying soil. To that end, we present a novel processing methodology that uses ASTER Band 2 (visible red), an interferometric SAR (IfSAR) digital surface model, and lidar-derived canopy height to classify biomass density using both a three-class scheme (high, medium and low) and a two-class scheme (high and low). Elevation adjustments associated with these classes using both median and quartile approaches were applied to adjust lidar-derived elevation values closer tomore »true bare earth elevation. The performance of the method was tested on 229 elevation points in the lower Apalachicola River Marsh. The two-class quartile-based adjusted DEM produced the best results, reducing the RMS error in elevation from 0.65 m to 0.40 m, a 38% improvement. The raw mean errors for the lidar DEM and the adjusted DEM were 0.61 ± 0.24 m and 0.32 ± 0.24 m, respectively, thereby reducing the high bias by approximately 49%.« less

  18. Surface-Layer Wind and Turbulence Profiling from LIDAR: Theory and Measurements

    E-Print Network [OSTI]

    Surface-Layer Wind and Turbulence Profiling from LIDAR: Theory and Measurements Régis DANIELIAN (Vestas Wind System) Hans Ejsing JØRGENSEN (Wind Energy Department, Risø. Contact: haej@risoe.dk) Torben MIKKELSEN (Wind Energy Department, Risø. Contact: tomi@risoe.dk) Jacob MANN (Wind Energy Department, Risø

  19. Upstream Measurements of Wind Profiles with Doppler Lidar for Improved Wind Energy Integration

    SciTech Connect (OSTI)

    Rodney Frehlich

    2012-10-30

    New upstream measurements of wind profiles over the altitude range of wind turbines will be produced using a scanning Doppler lidar. These long range high quality measurements will provide improved wind power forecasts for wind energy integration into the power grid. The main goal of the project is to develop the optimal Doppler lidar operating parameters and data processing algorithms for improved wind energy integration by enhancing the wind power forecasts in the 30 to 60 minute time frame, especially for the large wind power ramps. Currently, there is very little upstream data at large wind farms, especially accurate wind profiles over the full height of the turbine blades. The potential of scanning Doppler lidar will be determined by rigorous computer modeling and evaluation of actual Doppler lidar data from the WindTracer system produced by Lockheed Martin Coherent Technologies, Inc. of Louisville, Colorado. Various data products will be investigated for input into numerical weather prediction models and statistically based nowcasting algorithms. Successful implementation of the proposed research will provide the required information for a full cost benefit analysis of the improved forecasts of wind power for energy integration as well as the added benefit of high quality wind and turbulence information for optimal control of the wind turbines at large wind farms.

  20. Remote sensing the wind using Lidars and Sodars Ioannis Antoniou (1)

    E-Print Network [OSTI]

    masts for their mounting and the costs associated with the purchase, erection and instrumentation for wind energy applications. The first reason is that the cost (purchase, erection, instrumentation with power curve and resource assessment measurements. Both SODAR (SOund Detection And Ranging) and LIDAR

  1. ARCTIC OBSERVATIONS WITH THE UNIVERSITY OF WISCONSIN HIGH SPECTRAL RESOLUTION LIDAR

    E-Print Network [OSTI]

    Eloranta, Edwin W.

    ) as part of the US National Oceanic and At- mospheric Administration (NOAA) SEARCH program. SEARCH seeks- lution Lidar has provided nearly continuous data since its August 2005 deployment at Eureka, Canada (80N. An expanded transmitted beam and low pulse energy make the output beam eye safe. Using molecular scattering

  2. Lidars in Wind Energy Jakob Mann, Ferhat Bingl, Torben Mikkelsen, Ioannis Antoniou, Mike

    E-Print Network [OSTI]

    Lidars in Wind Energy Jakob Mann, Ferhat Bingöl, Torben Mikkelsen, Ioannis Antoniou, Mike Courtney, Gunner Larsen, Ebba Dellwik Juan Jose Trujillo* and Hans E. Jørgensen Wind Energy Department Risø of the presentation · Introduction to wind energy · Accurate profiles of the mean wind speed · Wakes behind turbines

  3. Bistatic receiver model for airborne lidar returns incident on an imaging array from underwater objects

    E-Print Network [OSTI]

    Singer, Andrew C

    returns from the surrounding water medium and ocean bottom. Our results provide a generalization ocean lidar return, obtained by a CCD array. © 2002 Optical Society of America OCIS codes: 010.3640, 030 a laser to generate a short, high-powered pulse of light. The transmitted laser beam can penetrate the air

  4. Biomass and Bioenergy 31 (2007) 646655 Estimating biomass of individual pine trees using airborne lidar

    E-Print Network [OSTI]

    2007-01-01

    Biomass and Bioenergy 31 (2007) 646­655 Estimating biomass of individual pine trees using airborne biomass and bio-energy feedstocks. The overall goal of this study was to develop a method for assessing aboveground biomass and component biomass for individual trees using airborne lidar data in forest settings

  5. Detailed Hydrographic Feature Extraction from High-Resolution LiDAR Data

    SciTech Connect (OSTI)

    Danny L. Anderson

    2012-05-01

    Detailed hydrographic feature extraction from high-resolution light detection and ranging (LiDAR) data is investigated. Methods for quantitatively evaluating and comparing such extractions are presented, including the use of sinuosity and longitudinal root-mean-square-error (LRMSE). These metrics are then used to quantitatively compare stream networks in two studies. The first study examines the effect of raster cell size on watershed boundaries and stream networks delineated from LiDAR-derived digital elevation models (DEMs). The study confirmed that, with the greatly increased resolution of LiDAR data, smaller cell sizes generally yielded better stream network delineations, based on sinuosity and LRMSE. The second study demonstrates a new method of delineating a stream directly from LiDAR point clouds, without the intermediate step of deriving a DEM. Direct use of LiDAR point clouds could improve efficiency and accuracy of hydrographic feature extractions. The direct delineation method developed herein and termed “mDn”, is an extension of the D8 method that has been used for several decades with gridded raster data. The method divides the region around a starting point into sectors, using the LiDAR data points within each sector to determine an average slope, and selecting the sector with the greatest downward slope to determine the direction of flow. An mDn delineation was compared with a traditional grid-based delineation, using TauDEM, and other readily available, common stream data sets. Although, the TauDEM delineation yielded a sinuosity that more closely matches the reference, the mDn delineation yielded a sinuosity that was higher than either the TauDEM method or the existing published stream delineations. Furthermore, stream delineation using the mDn method yielded the smallest LRMSE.

  6. Coherent anti-Stokes Raman scattering (CARS) optimized by exploiting optical interference 

    E-Print Network [OSTI]

    Wang, Xi

    2012-07-16

    The purpose of this work is to study the interference between the coherent nonresonant four-wave-mixing (FWM) background and the Raman-resonant signal in the coherent anti-Stokes Raman spectroscopy (CARS). The nonresonant background is usually...

  7. Fourier Transform Raman Spectroscopy of Photoactive Proteins with Near-Infrared Excitation

    E-Print Network [OSTI]

    Johnson, Carey K.; Rubinovitz, Ronald

    1990-07-01

    ) and bacteriopheophytin, bacteriochlorophyll, and carotenoids (in reaction centers). The relative intensities of retinylidene modes in the spectrum for nonresonant FT Raman spectroscopy of bacteriorhodopsin are nearly identical to those observed in the resonance Raman...

  8. Pulsed laser Raman spectroscopy in the laser-heated diamond anvil...

    Office of Scientific and Technical Information (OSTI)

    Pulsed laser Raman spectroscopy in the laser-heated diamond anvil cell Citation Details In-Document Search Title: Pulsed laser Raman spectroscopy in the laser-heated diamond anvil...

  9. Raman P. Singh School of Mechanical and Aerospace Engineering Phone (Tulsa): 918.594.8155

    E-Print Network [OSTI]

    Ghajar, Afshin J.

    Raman P. Singh School of Mechanical and Aerospace Engineering Phone (Tulsa): 918.594.8155 Oklahoma State University Phone (Stillwater): 405.744.1825 700 N. Greenwood Avenue, Tulsa, OK 74106 raman

  10. Nanoscale array structures suitable for surface enhanced raman scattering and methods related thereto

    DOE Patents [OSTI]

    Bond, Tiziana C.; Miles, Robin; Davidson, James C.; Liu, Gang Logan

    2014-07-22

    Methods for fabricating nanoscale array structures suitable for surface enhanced Raman scattering, structures thus obtained, and methods to characterize the nanoscale array structures suitable for surface enhanced Raman scattering. Nanoscale array structures may comprise nanotrees, nanorecesses and tapered nanopillars.

  11. Combined confocal Raman and quantitative phase microscopy system for biomedical diagnosis

    E-Print Network [OSTI]

    Kang, Jeon Woong

    We have developed a novel multimodal microscopy system that incorporates confocal Raman, confocal reflectance, and quantitative phase microscopy (QPM) into a single imaging entity. Confocal Raman microscopy provides detailed ...

  12. Nonresonant hyper?Raman and hyper?Rayleigh scattering in benzene and pyridine

    E-Print Network [OSTI]

    Neddersen, John P.; Mounter, Sarah A.; Bostick, James M.; Johnson, Carey K.

    1989-01-01

    Nonresonant hyper?Raman and hyper?Rayleigh spectra excited at 1064 nm are reported for neat benzene and pyridine. The theory of Herzberg–Teller vibronic coupling in nonresonant and preresonant hyper?Raman scattering is developed. Nonresonant hyper...

  13. Time?resolved anisotropic coherent anti?Stokes Raman scattering: A new probe of reorientational dynamics

    E-Print Network [OSTI]

    Wan, Chaozhi; Johnson, Carey K.

    1993-09-01

    A formalism for the time?dependent anisotropic third?order susceptibility induced by a linearly polarized excitation pulse has been derived to describe the time dependence of coherent anti?Stokes Raman scattered(CARS) and Raman time...

  14. Cone penetrometer fiber optic raman spectroscopy probe assembly

    DOE Patents [OSTI]

    Kyle, Kevin R. (Brentwood, CA); Brown, Steven B. (Livermore, CA)

    2000-01-01

    A chemically and mechanically robust optical Raman spectroscopy probe assembly that can be incorporated in a cone penetrometer (CPT) for subsurface deployment. This assembly consists of an optical Raman probe and a penetrometer compatible optical probe housing. The probe is intended for in-situ chemical analysis of chemical constituents in the surrounding environment. The probe is optically linked via fiber optics to the light source and the detection system at the surface. A built-in broadband light source provides a strobe method for direct measurement of sample optical density. A mechanically stable sapphire window is sealed directly into the side-wall of the housing using a metallic, chemically resistant, hermetic seal design. This window permits transmission of the interrogation light beam and the resultant signal. The spectroscopy probe assembly is capable of accepting Raman, Laser induced Fluorescence, reflectance, and other optical probes with collimated output for CPT deployment.

  15. UV resonance Raman analysis of trishomocubane and diamondoid dimers

    SciTech Connect (OSTI)

    Meinke, Reinhard Thomsen, Christian; Maultzsch, Janina; Richter, Robert; Merli, Andrea; Fokin, Andrey A.; Department of Organic Chemistry, Kiev Polytechnic Institute, pr. Pobedy 37, 03056 Kiev ; Koso, Tetyana V.; Schreiner, Peter R.; Rodionov, Vladimir N.

    2014-01-21

    We present resonance Raman measurements of crystalline trishomocubane and diamantane dimers containing a C=C double bond. Raman spectra were recorded with excitation energies between 2.33 eV and 5.42 eV. The strongest enhancement is observed for the C=C stretch vibration and a bending mode involving the two carbon atoms of the C=C bond, corresponding to the B{sub 2g} wagging mode of ethylene. This is associated with the localization of the ?-HOMO and LUMO and the elongation of the C=C bond length and a pyramidalization of the two sp{sup 2}-hybridized carbon atoms at the optical excitation. The observed Raman resonance energies of the trishomocubane and diamantane dimers are significantly lower than the HOMO-LUMO gaps of the corresponding unmodified diamondoids.

  16. Carrier-free Raman manipulation of trapped neutral atoms

    E-Print Network [OSTI]

    René Reimann; Wolfgang Alt; Tobias Macha; Dieter Meschede; Natalie Thau; Seokchan Yoon; Lothar Ratschbacher

    2014-12-02

    We experimentally realize an enhanced Raman control scheme for neutral atoms that features an intrinsic suppression of the two-photon carrier transition, but retains the sidebands which couple to the external degrees of freedom of the trapped atoms. This is achieved by trapping the atom at the node of a blue detuned standing wave dipole trap, that acts as one field for the two-photon Raman coupling. The improved ratio between cooling and heating processes in this configuration enables a five times lower fundamental temperature limit for resolved sideband cooling. We apply this method to perform Raman cooling to the two-dimensional vibrational ground state and to coherently manipulate the atomic motion. The presented scheme requires minimal additional resources and can be applied to experiments with challenging optical access, as we demonstrate by our implementation for atoms strongly coupled to an optical cavity.

  17. Chiral Topological Orders in an Optical Raman Lattice

    E-Print Network [OSTI]

    Xiong-Jun Liu; Zheng-Xin Liu; K. T. Law; W. Vincent Liu; T. K. Ng

    2014-09-14

    We find an optical Raman lattice without spin-orbit coupling showing chiral topological orders for cold atoms. Two incident plane-wave lasers are applied to generate simultaneously a double-well square lattice and periodic Raman couplings, the latter of which drive the nearest-neighbor hopping and create a staggered flux pattern across the lattice. Such a minimal setup is can yield the quantum anomalous Hall effect in the single particle regime, while in the interacting regime it achieves the $J_1$-$J_2$-$K$ model with all parameters controllable, which supports a chiral spin liquid phase. We further show that heating in the present optical Raman lattice is reduced by more than one order of magnitude compared with the conventional laser-assisted tunneling schemes. This suggests that the predicted topological states be well reachable with the current experimental capability.

  18. Estimating forest structural characteristics with airborne lidar scanning and a near-real time profiling laser systems 

    E-Print Network [OSTI]

    Zhao, Kaiguang

    2009-05-15

    LiDAR (Light Detection and Ranging) directly measures canopy vertical structures, and provides an effective remote sensing solution to accurate and spatiallyexplicit mapping of forest characteristics, such as canopy height and Leaf Area Index...

  19. Method to determine and adjust the alignment of the transmitter and receiver fields of view of a LIDAR system

    DOE Patents [OSTI]

    Schmitt, Randal L. (Tijeras, NM); Henson, Tammy D. (Albuquerque, NM); Krumel, Leslie J. (Cedar Crest, NM); Hargis, Jr., Philip J. (Albuquerque, NM)

    2006-06-20

    A method to determine the alignment of the transmitter and receiver fields of view of a light detection and ranging (LIDAR) system. This method can be employed to determine the far-field intensity distribution of the transmitter beam, as well as the variations in transmitted laser beam pointing as a function of time, temperature, or other environmental variables that may affect the co-alignment of the LIDAR system components. In order to achieve proper alignment of the transmitter and receiver optical systems when a LIDAR system is being used in the field, this method employs a laser-beam-position-sensing detector as an integral part of the receiver optics of the LIDAR system.

  20. Field Test Results of Using a Nacelle-Mounted Lidar for Improving Wind Energy Capture by Reducing Yaw Misalignment (Presentation)

    SciTech Connect (OSTI)

    Fleming, P.; Scholbrock, A.; Wright, A.

    2014-11-01

    Presented at the Nordic Wind Power Conference on November 5, 2014. This presentation describes field-test campaigns performed at the National Wind Technology Center in which lidar technology was used to improve the yaw alignment of the Controls Advanced Research Turbine (CART) 2 and CART3 wind turbines. The campaigns demonstrated that whether by learning a correction function to the nacelle vane, or by controlling yaw directly with the lidar signal, a significant improvement in power capture was demonstrated.

  1. Micro-Raman Spectroscopy of Algae: Composition Analysis and Fluorescence Background Behavior

    E-Print Network [OSTI]

    ARTICLE Micro-Raman Spectroscopy of Algae: Composition Analysis and Fluorescence Background performed using Stokes Raman scattering for compositional analysis of algae. Two algal species, Chlorella while acquiring Raman signals from the algae. The time dependence of fluorescence background is char

  2. Stimulated coherent anti-Stokes Raman spectroscopy (CARS) resonances originate from double-slit

    E-Print Network [OSTI]

    Mukamel, Shaul

    Stimulated coherent anti-Stokes Raman spectroscopy (CARS) resonances originate from double January 21, 2010 (received for review September 3, 2009) Coherent anti-Stokes Raman spectroscopy (CARS with re- spect to pulse parameters. CARS microscopy pulse shaping ultrafast spectroscpy Coherent Raman

  3. Variable temperature Raman microscopy as a nanometrology tool for graphene layers and graphene-based devices

    E-Print Network [OSTI]

    Variable temperature Raman microscopy as a nanometrology tool for graphene layers and graphene; accepted 24 July 2007; published online 15 August 2007 Raman microscopy of graphene was carried out over-band frequencies extracted from Raman spectra of the single-layer graphene are - 1.6±0.2 10-2 cm-1 /K and - 3

  4. Detection of Physiologically Relevant Alcohol Concentrations Using Raman Spectroscopy 

    E-Print Network [OSTI]

    McKay, Joshua L.

    2006-08-16

    . A. Watson, J. P. Wicksted, R. D. Stith, and W. F. March, ?Analysis of metabolites in aqueous solutions by using laser Raman spectroscopy,? Applied Optics, 32-6, 925-929, (1993). 5. A. J. Berger, Y. Wang, and M. S. Feld, ?Rapid, noninvasive... concentration measurements of aqueous biological analytes by near-infrared Raman spectroscopy,? Applied Optics, 35-1, 209-212, (1996). 29 6. A. J. Berger, I. Itzkan, and M. S. Feld, ?Feasibility of measuring blood glucose concentration by near...

  5. hal00276997, Raman spectra of misoriented bilayer graphene

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    hal­00276997, version 1 ­ 5 May 2008 Raman spectra of misoriented bilayer graphene P. Poncharal 1 spectra from single layer graphene with a bilayer in which the two layers are arbitrarily misoriented to the similarity of the electronic structures of single layer graphene and misoriented bilayer graphene. Another

  6. Raman Enhancement on Graphene: Adsorbed and Intercalated Molecular

    E-Print Network [OSTI]

    Raman Enhancement on Graphene: Adsorbed and Intercalated Molecular Species Naeyoung Jung intercalation into bulk graphite shifts the Fermi level of individual graphene-like sheets by charge-transfer doping; this process has been studied for many decades.1 With single or few layer thick graphenes

  7. Naderi and Raman 1 Design Considerations in Simulating Pedestrian Environments

    E-Print Network [OSTI]

    Naderi and Raman 1 Design Considerations in Simulating Pedestrian Environments Submitted: August 1 ABSTRACT Pedestrian Simulation is a new area of safety and health research employing contemporary these conditions, the simulated environment can be manipulated to further research in many aspects of pedestrian

  8. Raman Microscopy of Lithium-Manganese-Rich Cathodes

    SciTech Connect (OSTI)

    Ruther, Rose E [ORNL; Callender, Andrew F. [Tennessee Technological University; Zhou, Hui [ORNL; Martha, Surendra [Indian Institute of Technology, Hyderabad; Nanda, Jagjit [ORNL

    2014-01-01

    Lithium rich, manganese rich composites with general formula xLi2MnO3 (1-x)LiMO2 are promising candidates for high capacity and high voltage cathodes for lithium ion batteries. Lithium rich oxides crystallize as a nanocomposite of layered phases whose structure further evolves with electrochemical cycling. Raman spectroscopy is potentially a powerful tool to monitor the crystal chemistry and correlate phase changes with electrochemical behavior. While several groups have reported Raman spectra of lithium rich oxides, the data show considerable variability in terms of both the vibrational features observed and their interpretation. In this study Raman microscopy is used to investigate lithium-rich manganese-rich cathodes as a function of average charge and electrochemical cycling. LMR-NMC cycled at elevated temperature (60 C) has a modified crystal structure which may account for some of the observed increase in capacity. Contrary to some reports, no growth of a spinel phase is observed. However, analysis of the Raman spectra does indicate the structure of LMR-NMC deviates significantly from an ideal layered phase. The results also highlight the importance of using low laser power and large sample sizes to obtain consistent data sets.

  9. Postdoc Position in Microfluidics and Single Cell Raman Spectroscopy

    E-Print Network [OSTI]

    Horn, Matthias

    Postdoc Position in Microfluidics and Single Cell Raman Spectroscopy Department of Microbial and Environmental Microfluidics Group (http://web.mit.edu/romanstocker) Department of Civil & Environmental (junior or senior) with strong expertise in microfluidics and an interest in applying it to microbial

  10. Vibrational spectroscopy of polyatomic materials: Semiempirical calculations of anharmonic couplings and infrared and Raman linewidths in naphthalene and PETN crystals

    E-Print Network [OSTI]

    Tretiak, Sergei

    couplings and infrared and Raman linewidths in naphthalene and PETN crystals Andrei Piryatinski,* Sergei

  11. TARSHA-KURDI, F., LANDES, T., GRUSSENMEYER, P., (2008). Extended RANSAC algorithm for automatic detection of building roof planes from Lidar data.

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    2008-01-01

    detection of building roof planes from Lidar data. The Photogrammetric Journal of Finland. Vol. 21, n°1, 2008, pp.97-109. EXTENDED RANSAC ALGORITHM FOR AUTOMATIC DETECTION OF BUILDING ROOF PLANES FROM LIDAR the detection of 3D building roof planes are of crucial importance. For this purpose, this paper studies

  12. Proceedings of 2011 NSF Engineering Research and Innovation Conference, Atlanta, Georgia Grant #0856420 LiDAR and optical imaging for 3-D fracture orientations

    E-Print Network [OSTI]

    Maerz, Norbert H.

    #0856420 LiDAR and optical imaging for 3-D fracture orientations Otoo, J. N., Maerz, N. H. Missouri manifest themselves in rock cuts as ,,facets that can be measured by LIDAR or fracture ,,traces that can mechanical break or fracture of negligible tensile strength, it has a low shear strength and high fluid

  13. The application of Raman laser in gravity measurement and metrology

    SciTech Connect (OSTI)

    Ru, Ning; Zhang, Li; Wang, Yu; Fan, Shangchun

    2014-05-27

    Atom Interferometry is proved to be a potential method for measuring the acceleration of atoms due to Gravity, we are now building a feasible system of cold atom gravimeter, it is based on the atom interferometry technology by coherently manipulating the cold atoms in a fountain (with a height of 1m) with specific Raman lasers, the cold atom wave packet is splitted, combined, and then re-splitted in the process. Then the atomic wave packet will acquire different phase because of the different evolution path. The precise acceleration can be deduced through the precision measurement of atomic interference fringes phase, and this will be a high precision standard of acceleration. At present, the preparation of Raman laser and the precise control of the laser Frequency have been finished, and they have been proved to meet the requirements of the experiment.

  14. Optimum pulse shapes for stimulated Raman adiabatic passage

    E-Print Network [OSTI]

    G. S. Vasilev; A. Kuhn; N. V. Vitanov

    2009-06-10

    Stimulated Raman adiabatic passage (STIRAP), driven with pulses of optimum shape and delay has the potential of reaching fidelities high enough to make it suitable for fault-tolerant quantum information processing. The optimum pulse shapes are obtained upon reduction of STIRAP to effective two-state systems. We use the Dykhne-Davis-Pechukas (DDP) method to minimize nonadiabatic transitions and to maximize the fidelity of STIRAP. This results in a particular relation between the pulse shapes of the two fields driving the Raman process. The DDP-optimized version of STIRAP maintains its robustness against variations in the pulse intensities and durations, the single-photon detuning and possible losses from the intermediate state.

  15. Ultrafast stimulated Raman parallel adiabatic passage by shaped pulses

    SciTech Connect (OSTI)

    Dridi, G.; Guerin, S.; Hakobyan, V.; Jauslin, H. R.; Eleuch, H.

    2009-10-15

    We present a general and versatile technique of population transfer based on parallel adiabatic passage by femtosecond shaped pulses. Their amplitude and phase are specifically designed to optimize the adiabatic passage corresponding to parallel eigenvalues at all times. We show that this technique allows the robust adiabatic population transfer in a Raman system with the total pulse area as low as 3{pi}, corresponding to a fluence of one order of magnitude below the conventional stimulated Raman adiabatic passage process. This process of short duration, typically picosecond and subpicosecond, is easily implementable with the modern pulse shaper technology and opens the possibility of ultrafast robust population transfer with interesting applications in quantum information processing.

  16. Raman fiber optic probe assembly for use in hostile environments

    DOE Patents [OSTI]

    Schmucker, John E. (Hurt, VA); Falk, Jon C. (Pittsburgh, PA); Archer, William B. (Bethel Park, PA); Blasi, Raymond J. (Harrison City, PA)

    2000-01-01

    This invention provides a device for Raman spectroscopic measurement of composition and concentrations in a hostile environment by the use of a first fiber optic as a means of directing high intensity monochromatic light from a laser to the hostile environment and a second fiber optic to receive the lower intensity scattered light for transmittal to a monochromator for analysis. To avoid damage to the fiber optics, they are protected from the hostile environment. A preferred embodiment of the Raman fiber optic probe is able to obtain Raman spectra of corrosive gases and solutions at temperatures up to 600.degree. F. and pressures up to 2000 psi. The incident exciting fiber optic cable makes an angle of substantially 90.degree. with the collecting fiber optic cable. This 90.degree. geometry minimizes the Rayleigh scattering signal picked up by the collecting fiber, because the intensity of Rayleigh scattering is lowest in the direction perpendicular to the beam path of the exciting light and therefore a 90.degree. scattering geometry optimizes the signal to noise ratio.

  17. Achieving molecular selectivity in imaging using multiphoton Raman spectroscopy techniques

    SciTech Connect (OSTI)

    Holtom, Gary R. ); Thrall, Brian D. ); Chin, Beek Yoke ); Wiley, H Steven ); Colson, Steven D. )

    2000-12-01

    In the case of most imaging methods, contrast is generated either by physical properties of the sample (Differential Image Contrast, Phase Contrast), or by fluorescent labels that are localized to a particular protein or organelle. Standard Raman and infrared methods for obtaining images are based upon the intrinsic vibrational properties of molecules, and thus obviate the need for attached flurophores. Unfortunately, they have significant limitations for live-cell imaging. However, an active Raman method, called Coherent Anti-Stokes Raman Scattering (CARS), is well suited for microscopy, and provides a new means for imaging specific molecules. Vibrational imaging techniques, such as CARS, avoid problems associated with photobleaching and photo-induced toxicity often associated with the use of fluorescent labels with live cells. Because the laser configuration needed to implement CARS technology is similar to that used in other multiphoton microscopy methods, such as two -photon fluorescence and harmonic generation, it is possible to combine imaging modalities, thus generating simultaneous CARS and fluorescence images. A particularly powerful aspect of CARS microscopy is its ability to selectively image deuterated compounds, thus allowing the visualization of molecules, such as lipids, that are chemically indistinguishable from the native species.

  18. Plasmon enhanced Raman scattering effect for an atom near a carbon nanotube

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Bondarev, I. V.

    2015-01-01

    Quantum electrodynamics theory of the resonance Raman scattering is developed for an atom in a close proximity to a carbon nanotube. The theory predicts a dramatic enhancement of the Raman intensity in the strong atomic coupling regime to nanotube plasmon near-fields. This resonance scattering is a manifestation of the general electromagnetic surface enhanced Raman scattering effect, and can be used in designing efficient nanotube based optical sensing substrates for single atom detection, precision spontaneous emission control, and manipulation.

  19. Geometric effect on surface enhanced Raman scattering of nanoporous gold: Improving Raman scattering by tailoring ligament and nanopore ratios

    SciTech Connect (OSTI)

    Lang, X. Y.; Chen, L. Y.; Guan, P. F.; Fujita, T.; Chen, M. W. [WPI Advanced Institute for Materials Research, Tohoku University, Sendai 980-8577 (Japan)

    2009-05-25

    We have synthesized nanoporous gold (NPG) films with a nanostructure consisting of small nanopores and large gold ligaments by the combination of chemical dealloying and electroless plating. The NPG films exhibit dramatic improvement in surface enhanced Raman scattering (SERS) in comparison with the conventional NPG. The superior SERS effect of the NPG films results from the confluence effect of enhanced local surface plasmon fields and electromagnetic coupling between ligaments, as well as the weak plasmon damping with increasing gold ligament sizes.

  20. Microfabrication of Biological Machines for Sensing and Locomotion Ritu Raman, Mechanical Science and Engineering

    E-Print Network [OSTI]

    Kilian, Kristopher A.

    Microfabrication of Biological Machines for Sensing and Locomotion Ritu Raman, Mechanical Science the autonomous and synchronous contraction of engineered cardiac muscle as an actuator for locomotion.[1] · We

  1. In situ Raman spectroscopic studies of trimethylindium pyrolysis in an OMVPE reactor

    E-Print Network [OSTI]

    Anderson, Timothy J.

    In situ Raman spectroscopic studies of trimethylindium pyrolysis in an OMVPE reactor Chinho Park for OMVPE deposition of indium-containing compound semiconductors. The pyrolysi

  2. Tunable excitation source for coherent Raman spectroscopy based on a single fiber laser

    E-Print Network [OSTI]

    Adany, Peter; Arnett, David C.; Johnson, Carey K.; Hui, Rongqing

    2011-10-01

    We demonstrate a wavelength tunable optical excitation source for coherent Raman scattering (CRS) spectroscopy based on a single femtosecondfiber laser. Electrically controlled wavelength tuning of Stokes optical pulses ...

  3. Characterizing Aerosol Distributions and Optical Properties Using the NASA Langley High Spectral Resolution Lidar

    SciTech Connect (OSTI)

    Hostetler, Chris; Ferrare, Richard

    2013-02-14

    The objective of this project was to provide vertically and horizontally resolved data on aerosol optical properties to assess and ultimately improve how models represent these aerosol properties and their impacts on atmospheric radiation. The approach was to deploy the NASA Langley Airborne High Spectral Resolution Lidar (HSRL) and other synergistic remote sensors on DOE Atmospheric Science Research (ASR) sponsored airborne field campaigns and synergistic field campaigns sponsored by other agencies to remotely measure aerosol backscattering, extinction, and optical thickness profiles. Synergistic sensors included a nadir-viewing digital camera for context imagery, and, later in the project, the NASA Goddard Institute for Space Studies (GISS) Research Scanning Polarimeter (RSP). The information from the remote sensing instruments was used to map the horizontal and vertical distribution of aerosol properties and type. The retrieved lidar parameters include profiles of aerosol extinction, backscatter, depolarization, and optical depth. Products produced in subsequent analyses included aerosol mixed layer height, aerosol type, and the partition of aerosol optical depth by type. The lidar products provided vertical context for in situ and remote sensing measurements from other airborne and ground-based platforms employed in the field campaigns and was used to assess the predictions of transport models. Also, the measurements provide a data base for future evaluation of techniques to combine active (lidar) and passive (polarimeter) measurements in advanced retrieval schemes to remotely characterize aerosol microphysical properties. The project was initiated as a 3-year project starting 1 January 2005. It was later awarded continuation funding for another 3 years (i.e., through 31 December 2010) followed by a 1-year no-cost extension (through 31 December 2011). This project supported logistical and flight costs of the NASA sensors on a dedicated aircraft, the subsequent analysis and archival of the data, and the presentation of results in conferences, workshops, and publications. DOE ASR field campaigns supported under this project included - MAX-Mex /MILAGRO (2006) - TexAQS 2006/GoMACCS (2006) - CHAPS (2007) - RACORO (2009) - CARE/CalNex (2010) In addition, data acquired on HSRL airborne field campaigns sponsored by other agencies were used extensively to fulfill the science objectives of this project and the data acquired have been made available to other DOE ASR investigators upon request.

  4. Quantifying Surface Subsidence along US Highway 50, Reno County, KS using Terrestrial LiDAR

    E-Print Network [OSTI]

    Herrs, Andrew J.

    2010-04-23

    by Brett Bennett of the Kansas Geological Survey. Initial scouting of the study area was done with the help of Bob Henthorne from KDOT. LiDAR acquisition at each project site was accomplished with the help of Nick Laskares, Willy Rittase, Ken Stalder..., Mike Taylor, Lynn Watney, the Hutchinson KDOT maintenance crew, and KDOT’s Salina Regional Geology Department. Kwan Yee Cheng and Richard Styron also helped with plotting data in MATLAB. ArcMap techniques were demonstrated by Prabin Shilpakar from...

  5. Lidar Investigation of Tropical Nocturnal Boundary Layer Aerosols and Cloud Macrophysics

    SciTech Connect (OSTI)

    Manoj, M. G.; Devara, PC S.; Taraphdar, Sourav

    2013-10-01

    Observational evidence of two-way association between nocturnal boundary layer aerosols and cloud macrophysical properties under different meteorological conditions is reported in this paper. The study has been conducted during 2008-09 employing a high space-time resolution polarimetric micro-pulse lidar over a tropical urban station in India. Firstly, the study highlights the crucial role of boundary layer aerosols and background meteorology on the formation and structure of low-level stratiform clouds in the backdrop of different atmospheric stability conditions. Turbulent mixing induced by the wind shear at the station, which is associated with a complex terrain, is found to play a pivotal role in the formation and structural evolution of nocturnal boundary layer clouds. Secondly, it is shown that the trapping of energy in the form of outgoing terrestrial radiation by the overlying low-level clouds can enhance the aerosol mixing height associated with the nocturnal boundary layer. To substantiate this, the long-wave heating associated with cloud capping has been quantitatively estimated in an indirect way by employing an Advanced Research Weather Research and Forecasting (WRF-ARW) model version 2.2 developed by National Center for Atmospheric Research (NCAR), Colorado, USA, and supplementary data sets; and differentiated against other heating mechanisms. The present investigation as well establishes the potential of lidar remote-sensing technique in exploring some of the intriguing aspects of the cloud-environment relationship.

  6. Marine boundary layer structure as observed by space-based Lidar

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Luo, T.; Wang, Z.; Zhang, D.

    2015-12-03

    The marine boundary layer (MBL) structure is important to the exchange of heat, momentum, and moisture between oceans and the low atmosphere and to the marine low cloud processes. This paper explores MBL structure over the eastern Pacific region with a new 4 year satellite-based dataset. The MBL aerosol lidar backscattering from the CALIPSO (Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations) was used to identify the MBL top (BLH) and the mixing layer height (MLH). Results showed that MBL is generally decoupled with MLH / BLH ratio ranging from ? 0.5 to ? 0.8 and the MBL decoupling magnitude ismore »mainly controlled by estimated inversion strength (EIS) that affects the cloud top entrainment process. The systematic differences between drizzling and non-drizzling stratocumulus tops, which may relate to the meso-scale circulations or gravity wave in MBL, also show dependence on EIS. Further analysis indicated that the MBL shows similar decoupled structure for clear sky and cumulus cloud-topped conditions, but is better mixed under stratiform cloud breakup and overcast conditions.« less

  7. Lidar Measurements of the Vertical Distribution of Aerosol Optical and Physical Properties over Central Asia

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Chen, Boris B.; Sverdlik, Leonid G.; Imashev, Sanjar A.; Solomon, Paul A.; Lantz, Jeffrey; Schauer, James J.; Shafer, Martin M.; Artamonova, Maria S.; Carmichael, Gregory R.

    2013-01-01

    The vertical structure of aerosol optical and physical properties was measured by Lidar in Eastern Kyrgyzstan, Central Asia, from June 2008 to May 2009. Lidar measurements were supplemented with surface-based measurements of PM 2.5 and PM 10 mass and chemical composition in both size fractions. Dust transported into the region is common, being detected 33% of the time. The maximum frequency occurred in the spring of 2009. Dust transported to Central Asia comes from regional sources, for example, Taklimakan desert and Aral Sea basin, and from long-range transport, for example, deserts of Arabia, Northeast Africa, Iran, and Pakistan. Regionalmore »sources are characterized by pollution transport with maximum values of coarse particles within the planetary boundary layer, aerosol optical thickness, extinction coefficient, integral coefficient of aerosol backscatter, and minimum values of the Ångström exponent. Pollution associated with air masses transported over long distances has different characteristics during autumn, winter, and spring. During winter, dust emissions were low resulting in high values of the Ångström exponent (about 0.51) and the fine particle mass fraction (64%). Dust storms were more frequent during spring with an increase in coarse dust particles in comparison to winter. The aerosol vertical profiles can be used to lower uncertainty in estimating radiative forcing. « less

  8. Micro-Raman spectroscopic studies on the adhesive-dentine interface and the degree of conversion of dental adhesives 

    E-Print Network [OSTI]

    Miletic, Vesna

    2010-01-01

    A series of studies on monomer to polymer conversion in adhesive systems was undertaken using micro-Raman spectroscopy. A database of micro-Raman spectra was compiled for identification of tooth tissues and materials. ...

  9. Multiscalar line measurements in nonisobaric high-pressure underexpanded supersonic jets using rotational-vibrational raman spectroscopy 

    E-Print Network [OSTI]

    Cohen, Benjamin Nathan

    2009-05-15

    This work describes the development of a Raman spectroscopy system for measuring aerothermochemistry in high-speed jets and flames. A transmissive grating spectrometer was newly developed for capturing pure rotational Raman and rotationalvibrational...

  10. Many-body theory of surface-enhanced Raman scattering

    E-Print Network [OSTI]

    David J. Masiello; George C. Schatz

    2008-09-18

    A many-body Green's function approach to the microscopic theory of surface-enhanced Raman scattering is presented. Interaction effects between a general molecular system and a spatially anisotropic metal particle supporting plasmon excitations in the presence of an external radiation field are systematically included through many-body perturbation theory. Reduction of the exact effects of molecular-electronic correlation to the level of Hartree-Fock mean-field theory is made for practical initial implementation, while description of collective oscillations of conduction electrons in the metal is reduced to that of a classical plasma density; extension of the former to a Kohn-Sham density-functional or second-order M{\\o}ller-Plesset perturbation theory is discussed; further specialization of the latter to the random-phase approximation allows for several salient features of the formalism to be highlighted without need for numerical computation. Scattering and linear-response properties of the coupled system subjected to an external perturbing electric field in the electric-dipole interaction approximation are investigated. Both damping and finite-lifetime effects of molecular-electronic excitations as well as the characteristic fourth-power enhancement of the molecular Raman scattering intensity are elucidated from first principles. It is demonstrated that the presented theory reduces to previous models of surface-enhanced Raman scattering and leads naturally to a semiclassical picture of the response of a quantum-mechanical molecular system interacting with a spatially anisotropic classical metal particle with electronic polarization approximated by a discretized collection of electric dipoles.

  11. Using LiDAR and normalized difference vegetation index to remotely determine LAI and percent canopy cover at varying scales 

    E-Print Network [OSTI]

    Griffin, Alicia Marie Rutledge

    2009-05-15

    The use of airborne LiDAR (Light Detection and Ranging) as a direct method to evaluate forest canopy parameters is vital in addressing both forest management and ecological concerns. The overall goal of this study was to develop the use of airborne...

  12. Field Test Results from Lidar Measured Yaw Control for Improved Yaw Alignment with the NREL Controls Advanced Research Turbine: Preprint

    SciTech Connect (OSTI)

    Scholbrock, A.; Fleming, P.; Wright, A.; Slinger, C.; Medley, J.; Harris, M.

    2014-12-01

    This paper describes field tests of a light detection and ranging (lidar) device placed forward looking on the nacelle of a wind turbine and used as a wind direction measurement to directly control the yaw position of a wind turbine. Conventionally, a wind turbine controls its yaw direction using a nacelle-mounted wind vane. If there is a bias in the measurement from the nacelle-mounted wind vane, a reduction in power production will be observed. This bias could be caused by a number of issues such as: poor calibration, electromagnetic interference, rotor wake, or other effects. With a lidar mounted on the nacelle, a measurement of the wind could be made upstream of the wind turbine where the wind is not being influenced by the rotor's wake or induction zone. Field tests were conducted with the lidar measured yaw system and the nacelle wind vane measured yaw system. Results show that a lidar can be used to effectively measure the yaw error of the wind turbine, and for this experiment, they also showed an improvement in power capture because of reduced yaw misalignment when compared to the nacelle wind vane measured yaw system.

  13. Plant Species Classification using a 3D LIDAR Sensor and Machine Learning Ulrich Weiss and Peter Biber

    E-Print Network [OSTI]

    Zell, Andreas

    Plant Species Classification using a 3D LIDAR Sensor and Machine Learning Ulrich Weiss and Peter of the plant and species. Automatically distinguishing between plant species is a challenging task, because of the appearances and the differences between the plants used by humans, into a formal, computer understandable form

  14. Radar/Lidar Sensor Fusion for Car-Following on Highways Daniel Gohring, Miao Wang, Michael Schnurmacher, Tinosch Ganjineh

    E-Print Network [OSTI]

    Rojas, Raúl

    Radar/Lidar Sensor Fusion for Car-Following on Highways Daniel G¨ohring, Miao Wang, Michael Schn-time algorithm which enables an autonomous car to comfortably follow other cars at various speeds while keeping that depends on the position as well as the velocity of the followed car. Radar sensors provide reliable

  15. CLOUD FRACTION STATISTICS DERIVED FROM 2YEARS OF HIGH SPECTRAL RESOLUTION LIDAR DATA ACQUIRED AT EUREKA, CANADA.

    E-Print Network [OSTI]

    Eloranta, Edwin W.

    CLOUD FRACTION STATISTICS DERIVED FROM 2YEARS OF HIGH SPECTRAL RESOLUTION LIDAR DATA ACQUIRED(AHSRL) and the NOAA 8.6 mm wavelength cloud radar (MMCR). Both instruments have operated nearly continuously since Sept 2005. This paper presents a record of cloud cover, cloud altitude and cloud phase derived

  16. Saturation of the leading spike growth in backward Raman amplifiers

    SciTech Connect (OSTI)

    Malkin, V. M.; Fisch, N. J. [Department of Astrophysical Sciences, Princeton University, Princeton, New Jersey 08540 (United States); Toroker, Z. [Department of Electrical Engineering, Technion Israel Institute of Technology, Haifa 32000 (Israel)

    2014-09-15

    Backward Raman amplification of laser pulses in plasmas can produce nearly relativistic unfocused output intensities and multi-exawatt powers in compact devices. The largest achievable intensity depends on which of major competitive processes set this limit. It is shown here that the relativistic electron nonlinearity can cause saturation of the leading amplified spike intensity before filamentation instabilities develop. A simple analytical model for the saturation, which supports numerical simulations, is suggested. The upper limit for the leading output spike unfocused intensity is calculated.

  17. Realignment-enhanced coherent anti-Stokes Raman scattering (CARS) and three-dimensional imaging in anisotropic fluids

    E-Print Network [OSTI]

    A. V. Kachynski; A. N. Kuzmin; P. N. Prasad; I. I. Smalyukh

    2008-07-04

    We apply coherent anti-Stokes Raman Scattering (CARS) microscopy to characterize director structures in liquid crystals.

  18. Noise suppression and enhanced focusability in plasma Raman amplifier with multi-frequency pump

    E-Print Network [OSTI]

    Noise suppression and enhanced focusability in plasma Raman amplifier with multi-frequency pump A that backscatter of the desired seed pulse proceeds, the usual methods of noise suppression do not apply. In ideally uniform plasmas, the Raman instability of the plasma noise and precursor amplification

  19. ORIGINAL PAPER Calculation of infrared and Raman vibration modes of magnesite

    E-Print Network [OSTI]

    Cattin, Rodolphe

    ORIGINAL PAPER Calculation of infrared and Raman vibration modes of magnesite at high pressure) are used to obtain infrared (IR) and Raman magnesite vibration modes as they vary with pressure up to 50 approaches of vibrations in crystals based on empirical models suffer several drawbacks lead- ing

  20. Laser-Scanning Coherent Anti-Stokes Raman Scattering Microscopy and Applications to Cell Biology

    E-Print Network [OSTI]

    Xie, Xiaoliang Sunney

    Laser-Scanning Coherent Anti-Stokes Raman Scattering Microscopy and Applications to Cell Biology Ji 11747-3157 USA ABSTRACT Laser-scanning coherent anti-Stokes Raman scattering (CARS) microscopy with fast., 1990). Duncan et al. constructed the first CARS microscope by use of two dye laser beams

  1. Raman and IR spectra of butane: Anharmonic calculations and interpretation of room temperature spectra

    E-Print Network [OSTI]

    Potma, Eric Olaf

    Raman and IR spectra of butane: Anharmonic calculations and interpretation of room temperature-principles anharmonic calculations are carried out for the IR and Raman spectra of the CAH stretch- ing bands in butane.V. All rights reserved. 1. Introduction n-Butane is of great importance in several disciplines

  2. Raman scattering method and apparatus for measuring isotope ratios and isotopic abundances

    DOE Patents [OSTI]

    Harney, Robert C. (5665 Charlotte Way, No. 80, Livermore, CA 94550); Bloom, Stewart D. (141 Via Serena, Alamo, CA 94507)

    1978-01-01

    Raman scattering is used to measure isotope ratios and/or isotopic abundances. A beam of quasi-monochromatic photons is directed onto the sample to be analyzed, and the resulting Raman-scattered photons are detected and counted for each isotopic species of interest. These photon counts are treated mathematically to yield the desired isotope ratios or isotopic abundances.

  3. Fifth-order electronically non-resonant Raman scattering: two-dimensional Fourier deconvolution

    E-Print Network [OSTI]

    Kaufman, Laura

    Fifth-order electronically non-resonant Raman scattering: two-dimensional Fourier deconvolution information on the direct ®fth-order nuclear response as well as the hyper- polarizability responses can-resonant Raman scattering is one of the new multi-dimensional spectroscopic techniques that oers information

  4. Superconductivity-induced phonon anomalies in high-Tc superconductors: A Raman intensity study

    E-Print Network [OSTI]

    Sipe,J. E.

    Superconductivity-induced phonon anomalies in high-Tc superconductors: A Raman intensity study O. V of a number of Raman-active phonons below the superconducting transition temperature in YBa2Cu3O7 x , Bi2Sr2Ca to obtain information about the superconducting state.4 Several years ago, Friedl et al.5 ob- served

  5. A versatile femtosecond stimulated Raman spectroscopy setup with tunable pulses in the visible to near infrared

    SciTech Connect (OSTI)

    Zhu, Liangdong [Department of Physics, Oregon State University, Corvallis, Oregon 97331 (United States); Liu, Weimin [Department of Chemistry, Oregon State University, Corvallis, Oregon 97331 (United States); Fang, Chong, E-mail: Chong.Fang@oregonstate.edu [Department of Physics, Oregon State University, Corvallis, Oregon 97331 (United States); Department of Chemistry, Oregon State University, Corvallis, Oregon 97331 (United States)

    2014-07-28

    We demonstrate a versatile and efficient setup to perform femtosecond stimulated Raman spectroscopy (FSRS). Technical innovations are implemented to achieve the wavelength tunability for both the picosecond narrowband Raman pump pulse and femtosecond broadband Raman probe pulse. Using a simplified one-grating scheme in a home-built second harmonic bandwidth compressor followed by a two-stage noncollinear optical parametric amplifier, we tune the Raman pump pulse from ca. 480 to 750?nm. To generate the suitable Raman probe pulse in tandem, we rely on our recently demonstrated broadband up-converted multicolor array technique that readily provides tunable broadband laser sidebands across the visible to near-infrared range. This unique setup has unparalleled flexibility for conducting FSRS. We measure the ground-state Raman spectra of a cyclohexane standard using tunable pump-probe pairs at various wavelengths across the visible region. The best spectral resolution is ?12?cm{sup ?1}. By tuning the pump wavelength closer to the electronic absorption band of a photoacid pyranine in water, we observe the pre-resonantly enhanced Raman signal. The stimulated Raman gain of the 1627?cm{sup ?1} mode is increased by over 15 times.

  6. In situ Raman spectroscopy of lanthanum-strontium-cobaltite thin films

    E-Print Network [OSTI]

    Breucop, Justin Daniel

    2012-01-01

    Raman spectroscopy is used to probe the structural change of Lanthanum Strontium Cobaltite (La1.xSrxCoO 3 -8) thin films across change in composition (0%-60% strontium) and temperature (30*C-520°C). Raman shift peaks were ...

  7. Entangled radiation via a Raman-driven quantum-beat laser 

    E-Print Network [OSTI]

    Qamar, Sajid; Al-Amri, M.; Qamar, Shahid; Zubairy, M. Suhail

    2009-01-01

    We propose a scheme for the entanglement generation of two cavity modes using a four-level Raman-driven quantum-beat laser (QBL). The atomic coherence is generated by a Raman-type two-photon process. Two different sufficient conditions...

  8. Continuous-wave high-power rotational Raman generation in molecular deuterium

    E-Print Network [OSTI]

    Yavuz, Deniz

    Continuous-wave high-power rotational Raman generation in molecular deuterium J. T. Green, D. E the generation of more than 300 mW of rotational Stokes output power in a CW Raman laser. The generation and the generated wavelengths. Advances in high-reflectivity, ultralow loss dielectric coatings have allowed CW

  9. Tunable Femtosecond Pulse Generation and Applications in Raman Micro-Spectroscopy 

    E-Print Network [OSTI]

    Peng, Jiahui

    2010-10-12

    reported tuning range for efficient nonlinear optical frequency conversion obtained with such a simple and low energy laser. We apply such a Ti:sapphire laser to Raman micro-spectroscopy. Because of the different temporal behaviors of the Raman process...

  10. Multi-wavelength Raman scattering of nanostructured Al-doped zinc oxide

    SciTech Connect (OSTI)

    Russo, V.; Ghidelli, M.; Gondoni, P. [Dipartimento di Energia and NEMAS, Center for Nanoengineered Materials and Surfaces, Politecnico di Milano, via Ponzio 34/3, I-20133 Milano (Italy); Casari, C. S.; Li Bassi, A. [Dipartimento di Energia and NEMAS, Center for Nanoengineered Materials and Surfaces, Politecnico di Milano, via Ponzio 34/3, I-20133 Milano (Italy); Center for Nano Science and Technology PoliMI, Istituto Italiano di Tecnologia, Via Pascoli 70/3, I-20133 Milano (Italy)

    2014-02-21

    In this work we present a detailed Raman scattering investigation of zinc oxide and aluminum-doped zinc oxide (AZO) films characterized by a variety of nanoscale structures and morphologies and synthesized by pulsed laser deposition under different oxygen pressure conditions. The comparison of Raman spectra for pure ZnO and AZO films with similar morphology at the nano/mesoscale allows to investigate the relation between Raman features (peak or band positions, width, relative intensity) and material properties such as local structural order, stoichiometry, and doping. Moreover Raman measurements with three different excitation lines (532, 457, and 325?nm) point out a strong correlation between vibrational and electronic properties. This observation confirms the relevance of a multi-wavelength Raman investigation to obtain a complete structural characterization of advanced doped oxide materials.

  11. Differential high-resolution stimulated CW Raman spectroscopy of hydrogen in a hollow-core fiber

    E-Print Network [OSTI]

    Westergaard, Philip G; Petersen, Jan C

    2015-01-01

    We demonstrate sensitive high-resolution stimulated Raman measurements of hydrogen using a hollow-core photonic crystal fiber (HC-PCF). The Raman transition is pumped by a narrow linewidth (laser. The probe light is produced by a homebuilt CW optical parametric oscillator (OPO), tunable from around 800 nm to 1300 nm (linewidth ~ 5 MHz). These narrow linewidth lasers allow for an excellent spectral resolution of approximately 10^-4 cm^(-1). The setup employs a differential measurement technique for noise rejection in the probe beam, which also eliminates background signals from the fiber. With the high sensitivity obtained, Raman signals were observed with only a few mW of optical power in both the pump and probe beams. This demonstration allows for high resolution Raman identification of molecules and quantification of Raman signal strengths.

  12. Deep-Ultraviolet Resonance Raman Excitation Profiles of NH4NO3, PETN, TNT, HMX, and RDX

    E-Print Network [OSTI]

    Asher, Sanford A.

    Deep-Ultraviolet Resonance Raman Excitation Profiles of NH4NO3, PETN, TNT, HMX, and RDX Manash nitrate (NH4NO3), pentaerythritol tetranitrate (PETN), trinitrotoluene (TNT), nitroamine (HMX. The ultraviolet (UV) resonance Raman/differential Raman cross-sections of NH4NO3, PETN, TNT, HMX, and RDX

  13. Pump side scattering in ultrapowerful backward Raman amplifiers A. A. Solodov, V. M. Malkin, and N. J. Fisch

    E-Print Network [OSTI]

    Pump side scattering in ultrapowerful backward Raman amplifiers A. A. Solodov, V. M. Malkin, and N of a laser pump by plasma noise might be suppressed by an appropriate detuning of the Raman resonance, even scattering of laser pumps by plasma noise in backward Raman amplifiers. Though its growth rate is smaller

  14. The effect of substrates on the Raman spectrum of graphene: Graphene-on-sapphire and graphene-on-glass

    E-Print Network [OSTI]

    The effect of substrates on the Raman spectrum of graphene: Graphene- on-sapphire and graphene The authors investigated the influence of substrates on Raman scattering spectrum from graphene. The room-temperature Raman signatures from graphene layers on GaAs, sapphire, and glass substrates were compared with those

  15. New C-H Stretching Vibrational Spectral Features in the Raman Spectra of Gaseous and Liquid Ethanol

    E-Print Network [OSTI]

    Liu, Shilin

    New C-H Stretching Vibrational Spectral Features in the Raman Spectra of Gaseous and Liquid Ethanol Traditionally, the Raman spectrum of ethanol in the C-H vibrational stretching region between 2800 cm-1 and 3100, and the -CH3 antisymmetric stretching. In this report, new Raman spectral features were observed for ethanol

  16. Cloud Effects on Radiative Heating Rate Profiles over Darwin using ARM and A-train Radar/Lidar Observations

    SciTech Connect (OSTI)

    Thorsen, Tyler J.; Fu, Qiang; Comstock, Jennifer M.

    2013-06-11

    Observations of clouds from the ground-based U.S. Department of Energy Atmospheric Radiation Measurement program (ARM) and satellite-based A-train are used to compute cloud radiative forcing profiles over the ARM Darwin, Australia site. Cloud properties are obtained from both radar (the ARM Millimeter Cloud Radar (MMCR) and the CloudSat satellite in the A-train) and lidar (the ARM Micropulse lidar (MPL) and the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) satellite in the A-train) observations. Cloud microphysical properties are taken from combined radar and lidar retrievals for ice clouds and radar only or lidar only retrievals for liquid clouds. Large, statistically significant differences of up to 1.43 K/day exist between the mean ARM and A-train net cloud radiative forcing profiles. The majority of the difference in cloud radiative forcing profiles is shown to be due to a large difference in the cloud fraction above 12 km. Above this altitude the A-train cloud fraction is significantly larger because more clouds are detected by CALIPSO than by the ground-based MPL. It is shown that the MPL is unable to observe as many high clouds as CALIPSO due to being more frequently attenuated and a poorer sensitivity even in otherwise clear-sky conditions. After accounting for cloud fraction differences and instrument sampling differences due to viewing platform we determined that differences in cloud radiative forcing due to the retrieved ice cloud properties is relatively small. This study demonstrates that A-train observations are better suited for the calculation cloud radiative forcing profiles. In addition, we find that it is necessary to supplement CloudSat with CALIPSO observations to obtain accurate cloud radiative forcing profiles since a large portion of clouds at Darwin are detected by CALIPSO only.

  17. Surface-Enhanced Raman Optical Data Storage system

    DOE Patents [OSTI]

    Vo-Dinh, T.

    1994-06-28

    An improved Surface-Enhanced Raman Optical Data Storage System (SERODS) is disclosed. In the improved system, entities capable of existing in multiple reversible states are present on the storage device. Such entities result in changed Surface-Enhanced Raman Scattering (SERS) when localized state changes are effected in less than all of the entities. Therefore, by changing the state of entities in localized regions of a storage device, the SERS emissions in such regions will be changed. When a write-on device is controlled by a data signal, such a localized regions of changed SERS emissions will correspond to the data written on the device. The data may be read by illuminating the surface of the storage device with electromagnetic radiation of an appropriate frequency and detecting the corresponding SERS emissions. Data may be deleted by reversing the state changes of entities in regions where the data was initially written. In application, entities may be individual molecules which allows for the writing of data at the molecular level. A read/write/delete head utilizing near-field quantum techniques can provide for a write/read/delete device capable of effecting state changes in individual molecules, thus providing for the effective storage of data at the molecular level. 18 figures.

  18. Sedimentological Reinterpretation of Surficial Unconsolidated Debris Flows and Stream Deposits of the Southern Flanks of Grand Mesa, CO: An Integrated LiDAR Approach 

    E-Print Network [OSTI]

    Blakeley, Mitchell W.

    2014-08-08

    . This study developed a sedimentological description and interpretation of these deposits and tested the capabilities of terrestrial LiDAR (Light Detection and Ranging) for use in sedimentological studies. This research addressed the origin of the deposits...

  19. The Ability of MM5 to Simulate Ice Clouds: Systematic Comparison between Simulated and Measured Fluxes and Lidar/Radar Profiles at the

    E-Print Network [OSTI]

    Protat, Alain

    -term meteorological measurements by active (radar and lidar) and passive (infrared and visible fluxes) remote sensing effect is governed primarily by the equi- librium between their albedo effect and their green- house

  20. Operating Regime for a Backward Raman Laser Amplifier in Preformed Plasma

    SciTech Connect (OSTI)

    Daniel S. Clark; Nathaniel J. Fisch

    2003-02-06

    A critical issue in the generation of ultra-intense, ultra-short laser pulses by backward Raman scattering in plasma is the stability of the pumping pulse to premature backscatter from thermal fluctuations in the preformed plasma. Malkin et al. [V.M. Malkin, et al., Phys. Rev. Lett. 84 (6):1208-1211, 2000] demonstrated that density gradients may be used to detune the Raman resonance in such a way that backscatter of the pump from thermal noise can be stabilized while useful Raman amplification persists. Here plasma conditions for which the pump is stable to thermal Raman backscatter in a homogeneous plasma and the density gradients necessary to stabilize the pump for other plasma conditions are quantified. Other ancillary constraints on a Raman amplifier are also considered to determine a specific region in the Te-he plane where Raman amplification is feasible. By determining an operability region, the degree of uncertainty in density or temperature tolerable for an experimental Raman amplifier is thus also identified. The fluid code F3D, which includes the effects of thermal fluctuations, is used to verify these analytic estimates.

  1. Method And System For Examining Biological Materials Using Low Power Cw Excitation Raman Spectroscopy.

    DOE Patents [OSTI]

    Alfano, Robert R. (Bronx, NY); Wang, Wubao (Flushing, NY)

    2003-05-06

    A method and system for examining biological materials using low-power cw excitation Raman spectroscopy. A low-power continuous wave (cw) pump laser beam and a low-power cw Stokes (or anti-Stokes) probe laser beam simultaneously illuminate a biological material and traverse the biological material in collinearity. The pump beam, whose frequency is varied, is used to induce Raman emission from the biological material. The intensity of the probe beam, whose frequency is kept constant, is monitored as it leaves the biological material. When the difference between the pump and probe excitation frequencies is equal to a Raman vibrational mode frequency of the biological material, the weak probe signal becomes amplified by one or more orders of magnitude (typically up to about 10.sup.4 -10.sup.6) due to the Raman emission from the pump beam. In this manner, by monitoring the intensity of the probe beam emitted from the biological material as the pump beam is varied in frequency, one can obtain an excitation Raman spectrum for the biological material tested. The present invention may be applied to in the in vivo and/or in vitro diagnosis of diabetes, heart disease, hepatitis, cancers and other diseases by measuring the characteristic excitation Raman lines of blood glucose, cholesterol, serum glutamic oxalacetic transaminase (SGOT)/serum glutamic pyruvic transaminase (SGPT), tissues and other corresponding Raman-active body constituents, respectively.

  2. Method And System For Examining Biological Materials Using Low Power Cw Excitation Raman Spectroscopy.

    DOE Patents [OSTI]

    Alfano, Robert R. (Bronx, NY); Wang, Wubao (Flushing, NY)

    2000-11-21

    A method and system for examining biological materials using low-power cw excitation Raman spectroscopy. In accordance with the teachings of the invention, a low-power continuous wave (cw) pump laser beam and a low-power cw Stokes (or anti-Stokes) probe laser beam simultaneously illuminate a biological material and traverse the biological material in collinearity. The pump beam, whose frequency is varied, is used to induce Raman emission from the biological material. The intensity of the probe beam, whose frequency is kept constant, is monitored as it leaves the biological material. When the difference between the pump and probe excitation frequencies is equal to a Raman vibrational mode frequency of the biological material, the weak probe signal becomes amplified by one or more orders of magnitude (typically up to about 10.sup.4 -10.sup.6) due to the Raman emission from the pump beam. In this manner, by monitoring the intensity of the probe beam emitted from the biological material as the pump beam is varied in frequency, one can obtain an excitation Raman spectrum for the biological material tested. The present invention may be applied to in the in vivo and/or in vitro diagnosis of diabetes, heart disease, hepatitis, cancers and other diseases by measuring the characteristic excitation Raman lines of blood glucose, cholesterol, serum glutamic oxalacetic transaminase (SGOT)/serum glutamic pyruvic tansaminase (SGPT), tissues and other corresponding Raman-active body constituents, respectively. For example, it may also be used to diagnose diseases associated with the concentration of Raman-active constituents in urine, lymph and saliva It may be used to identify cancer in the breast, cervix, uterus, ovaries and the like by measuring the fingerprint excitation Raman spectra of these tissues. It may also be used to reveal the growing of tumors or cancers by measuring the levels of nitric oxide in tissue.

  3. Nonlinear-optical spectral interferometry of nanostructures using coherent anti-Stokes Raman scattering

    SciTech Connect (OSTI)

    Konorov, Stanislav O; Mitrokhin, V P; Fedotov, Andrei B; Zheltikov, Aleksei M; Smirnova, I V; Sidorov-Biryukov, D A

    2005-01-31

    The spectrum of coherent anti-Stokes Raman scattering (CARS) from Raman-active vibrations of gas-phase nitrogen molecules in a mesoporous silica aerogel host is experimentally studied. The CARS spectral profile under these conditions is a result of interference of the resonant part of nonlinear susceptibility, originating from nitrogen molecules in aerogel pores, and the nonresonant contribution, related to the mesoporous host. Raman-active modes of gas-phase molecular nitrogen give rise to intense resonances in the CARS spectrum, serving as reference spectral profiles for probing local parameters of a nanocomposite material (nanoCARS). (laser applications and other topics in quantum electronics)

  4. Third harmonic stimulated Raman backscattering of laser in a magnetized plasma

    SciTech Connect (OSTI)

    Paknezhad, Alireza; Dorranian, Davoud

    2013-09-15

    This article studies the nonlinear Raman shifted third harmonic backscattering of an intense extraordinary laser wave through a homogenous transversely magnetized cold plasma. Due to the relativistic nonlinearity, the plasma dynamic is modified in the presence of transversely magnetic field, and this can generate the third harmonic scattered wave and an electrostatic upper hybrid wave via the Raman scattering process. Using the nonlinear wave equation, the mechanism of nonlinear third harmonic Raman scattering is discussed in detail to obtain the maximum growth rate of instability in the mildly relativistic regime. The growth rate decreases as the static magnetic field increases. It also increases with the pump wave amplitude.

  5. Raman spectroscopy of graphite in high magnetic fields: Electron-phonon coupling and magnetophonon resonance

    SciTech Connect (OSTI)

    Kim, Younghee; Smirnov, Dmitry; Kalugin, Nikolai G.; Lombardo, Antonio; Ferrari, Andrea C.

    2013-12-04

    The magneto-Raman measurements of graphite were performed in a back-scattering Faraday geometry at temperature 10 K in magnetic fields up to 45 T. The experimental data reveal the rich structure of Raman-active excitations dominated by K-point massive electrons. At high magnetic fields the graphite E{sub 2g} Raman line shows complex multi- component behavior interpreted as magnetophonon resonance coupled electron-phonon modes at graphite’s K-point. Also we found the clear signature of the fundamental, strongly dumped, n=0 magnetophonon resonance associated with H point massless holes.

  6. Q-branch Raman scattering and modern kinetic thoery

    SciTech Connect (OSTI)

    Monchick, L. [The Johns Hopkins Univ., Laurel, MD (United States)

    1993-12-01

    The program is an extension of previous APL work whose general aim was to calculate line shapes of nearly resonant isolated line transitions with solutions of a popular quantum kinetic equation-the Waldmann-Snider equation-using well known advanced solution techniques developed for the classical Boltzmann equation. The advanced techniques explored have been a BGK type approximation, which is termed the Generalized Hess Method (GHM), and conversion of the collision operator to a block diagonal matrix of symmetric collision kernels which then can be approximated by discrete ordinate methods. The latter method, which is termed the Collision Kernel method (CC), is capable of the highest accuracy and has been used quite successfully for Q-branch Raman scattering. The GHM method, not quite as accurate, is applicable over a wider range of pressures and has proven quite useful.

  7. Linear optics, Raman scattering, and spin noise spectroscopy

    E-Print Network [OSTI]

    Glazov, M M

    2015-01-01

    Spin noise spectroscopy (SNS) is a new method for studying magnetic resonance and spin dynamics based on measuring the Faraday rotation noise. In strong contrast with methods of nonlinear optics, the spectroscopy of spin noise is considered to be essentially nonperturbative. Presently, however, it became clear that the SNS, as an optical technique, demonstrates properties lying far beyond the bounds of conventional linear optics. Specifically, the SNS shows dependence of the signal on the light power density, makes it possible to penetrate inside an inhomogeneously broadened absorption band and to determine its homogeneous width, allows one to realize an effective pump-probe spectroscopy without any optical nonlinearity, etc. This may seem especially puzzling when taken into account that SNS can be considered just as a version of Raman spectroscopy, which is known to be deprived of such abilities. In this paper, we clarify this apparent inconsistency.

  8. Surface enhanced Raman gene probe and methods thereof

    DOE Patents [OSTI]

    Vo-Dinh, T.

    1998-02-24

    The subject invention disclosed is a new gene probe biosensor and methods based on surface enhanced Raman scattering (SERS) label detection. The SER gene probe biosensor comprises a support means, a SER gene probe having at least one oligonucleotide strand labeled with at least one SERS label, and a SERS active substrate disposed on the support means and having at least one of the SER gene probes adsorbed thereon. Biotargets such as bacterial and viral DNA, RNA and PNA are detected using a SER gene probe via hybridization to oligonucleotide strands complementary to the SER gene probe. The support means includes a fiberoptic probe, an array of fiberoptic probes for performance of multiple assays and a waveguide microsensor array with charge-coupled devices or photodiode arrays. 18 figs.

  9. Surface enhanced Raman gene probe and methods thereof

    DOE Patents [OSTI]

    Vo-Dinh, T.

    1998-09-29

    The subject invention disclosed herein is a new gene probe biosensor and methods based on surface enhanced Raman scattering (SERS) label detection. The SER gene probe biosensor comprises a support means, a SER gene probe having at least one oligonucleotide strand labeled with at least one SERS label, and a SERS active substrate disposed on the support means and having at least one of the SER gene probes adsorbed thereon. Biotargets such as bacterial and viral DNA, RNA and PNA are detected using a SER gene probe via hybridization to oligonucleotide strands complementary to the SER gene probe. The support means supporting the SERS active substrate includes a fiberoptic probe, an array of fiberoptic probes for performance of multiple assays and a waveguide microsensor array with charge-coupled devices or photodiode arrays. 18 figs.

  10. Surface enhanced Raman gene probe and methods thereof

    DOE Patents [OSTI]

    Vo-Dinh, T.

    1998-07-21

    The subject invention disclosed is a new gene probe biosensor and methods based on surface enhanced Raman scattering (SERS) label detection. The SER gene probe biosensor comprises a support means, a SER gene probe having at least one oligonucleotide strand labeled with at least one SERS label, and a SERS active substrate disposed on the support means and having at least one of the SER gene probes adsorbed. Biotargets such as bacterial and viral DNA, RNA and PNA are detected using a SER gene probe via hybridization to oligonucleotide strands complementary to the SER gene probe. The support means supporting the SERS active substrate includes a fiberoptic probe, an array of fiberoptic probes for performance of multiple assays and a waveguide microsensor array with charge-coupled devices or photodiode arrays. 18 figs.

  11. Stimulated Raman adiabatic passage in an extended ladder system

    SciTech Connect (OSTI)

    Niu Yingyu; Wang Rong; Qiu Minghui [School of Science, Dalian Jiaotong University, Dalian 116028 (China)

    2011-08-15

    The rovibrational dynamics of an extended ladder stimulated Raman adiabatic passage (STIRAP) system through permanent dipole moment transitions is investigated theoretically using the time-dependent quantum-wave-packet method for the ground electronic state of the HF molecule. The calculated results show that nearly 100% of the population can be transferred to the target state through (1+2), (1+3), and (2+2) STIRAP schemes. By choosing a suitable excitation pathway, the effects of the background states on the final population of the target state can be removed. For the multiphoton STIRAP process, the one-photon overtone pump scheme is more efficient than the two-photon pump scheme in controlling the population transfer to the target state.

  12. Nanosensors based on functionalized nanoparticles and surface enhanced raman scattering

    DOE Patents [OSTI]

    Talley, Chad E. (Brentwood, CA); Huser, Thomas R. (Livermore, CA); Hollars, Christopher W. (Brentwood, CA); Lane, Stephen M. (Oakland, CA); Satcher, Jr., Joe H. (Patterson, CA); Hart, Bradley R. (Brentwood, CA); Laurence, Ted A. (Livermore, CA)

    2007-11-27

    Surface-Enhanced Raman Spectroscopy (SERS) is a vibrational spectroscopic technique that utilizes metal surfaces to provide enhanced signals of several orders of magnitude. When molecules of interest are attached to designed metal nanoparticles, a SERS signal is attainable with single molecule detection limits. This provides an ultrasensitive means of detecting the presence of molecules. By using selective chemistries, metal nanoparticles can be functionalized to provide a unique signal upon analyte binding. Moreover, by using measurement techniques, such as, ratiometric received SERS spectra, such metal nanoparticles can be used to monitor dynamic processes in addition to static binding events. Accordingly, such nanoparticles can be used as nanosensors for a wide range of chemicals in fluid, gaseous and solid form, environmental sensors for pH, ion concentration, temperature, etc., and biological sensors for proteins, DNA, RNA, etc.

  13. Harnessing Chemical Raman Enhancement for Understanding Organic Adsorbate Binding on Metal Surfaces

    E-Print Network [OSTI]

    Zayak, Alexey

    2014-01-01

    P. J. ; Neaton, J. B. Chemical Raman Enhancement of OrganicJ. ; Zhao, K. ; Zhang, Z. Chemical contribution to Surface-the Molecule-Surface chemical coupling in SERS. J. Am. Chem.

  14. Raman Spectroscopy Provides a Powerful Diagnostic Tool for Accurate Determination of Albumin Glycation

    E-Print Network [OSTI]

    Dingari, Narahara Chari

    We present the first demonstration of glycated albumin detection and quantification using Raman spectroscopy without the addition of reagents. Glycated albumin is an important marker for monitoring the long-term glycemic ...

  15. Photo-oxidation of Ge Nanocrystals: Kinetic Measurements by In Situ Raman Spectroscopy

    E-Print Network [OSTI]

    2008-01-01

    Photo-oxidation of Ge Nanocrystals: Kinetic Measurements byBerkeley, CA, 94720 ABSTRACT Ge nanocrystals are formed inthe Raman spectra of the Ge nanocrystals in-situ. The

  16. Femtosecond pure-rotational coherent anti-stokes raman scattering gas phase diagnostics.

    SciTech Connect (OSTI)

    Kearney, Sean Patrick; Serrano, Justin Raymond

    2010-12-01

    We discuss recent experiments for the characterization of our femtosecond pure rotational CARS facility for observation of Raman transients in N{sub 2} and atmospheric air. The construction of a simplified femtosecond four-wave mixing system with only a single laser source is presented. Pure-rotational Raman transients reveal well-ordered time-domain recurrence peaks associated with the near-uniform spacing of rotational Raman peaks in the spectral domain. Long-time, 100-ps duration observations of the transient Raman polarization are presented, and the observed transients are compared to simulated results. Fourier transformation of the transients reveals two distinct sets of beat frequencies. Simulation results for temperatures from 300-700 K are used to illustrate the temperature sensitivity of the time-domain transients and their Fourier-transform counterparts. And strategies for diagnostics are briefly discussed. These results are being utilized to develop gas-phase measurement strategies for temperature and species concentration.

  17. Single-fiber-laser-based wavelength tunable excitation for coherent Raman spectroscopy

    E-Print Network [OSTI]

    Su, Jue; Xie, Ruxin; Johnson, Carey K.; Hui, Rongqing

    2013-06-01

    We demonstrate coherent Raman spectroscopy (CRS) using a tunable excitation source based on a single femtosecond fiber laser. The frequency difference between the pump and the Stokes pulses was generated by soliton self-frequency shifting in a...

  18. Solar Energy Materials & Solar Cells 71 (2002) 511522 In situ Raman spectroscopy of the

    E-Print Network [OSTI]

    Nabben, Reinhard

    2002-01-01

    Solar Energy Materials & Solar Cells 71 (2002) 511­522 In situ Raman spectroscopy. In this situation, a low energy excitation (e.g. visible light) is needed to excite an electron to a neighboring

  19. Uniaxial strain in graphene by Raman spectroscopy: G peak splitting, Grüneisen parameters, and sample orientation

    E-Print Network [OSTI]

    Mohiuddin, T. M. G.

    We uncover the constitutive relation of graphene and probe the physics of its optical phonons by studying its Raman spectrum as a function of uniaxial strain. We find that the doubly degenerate E[subscript 2g] optical mode ...

  20. Zone folding effect in Raman G-band intensity of twisted bilayer graphene

    E-Print Network [OSTI]

    Dresselhaus, Mildred

    The G-band Raman intensity is calculated for twisted bilayer graphene as a function of laser excitation energy based on the extended tight binding method. Here we explicitly consider the electron-photon and electron-phonon ...

  1. Mapping residual stress fields from Vickers hardness indents using Raman microprobe spectroscopy

    SciTech Connect (OSTI)

    Sparks, R.G.; Enloe, W.S.; Paesler, M.A.

    1988-12-01

    Micro-Raman spectroscopy is used to map the residual stress fields in the vicinity of Vickers hardness indents. Both 514.5 and 488.0 nm, light is used to excite the effect and the resulting shifted and broadened Raman peaks are analyzed using computer deconvolution. Half-wave plates are used to vary the orientation of the incident later light`s polarization state with respect to crystal orientation. The Raman scattered light is then analyzed for polarization dependences which are indicative of the various components of the Raman scattering tensor. Such studies can yield valuable information about the orientation of stress components in a well known stress field. The results can then be applied to the determination of stress components in machined semiconductor materials.

  2. Role of noise operators on two-photon correlations in an extended coherent Raman medium 

    E-Print Network [OSTI]

    Ooi, C. H. Raymond; Zubairy, M. Suhail.

    2007-01-01

    An extended medium driven in a double Raman configuration generates Stokes and anti-Stokes fields that are described by coupled parametric oscillator equations with solutions that depend on input boundary operators and quantum noise operators. We...

  3. ROTATIONAL AND VIBRATIONAL RAMAN SPECTROSCOPY FOR FLOW FROM AN UNDEREXPANDED JET NOZZLE 

    E-Print Network [OSTI]

    Bayeh, Alexander

    2008-08-19

    The objective of this work is the construction of a fully functioning Raman line imaging spectrometer; and the measurement of pressure, temperature, and chemical concentration in supersonic flows issuing from a jet nozzle. The measurements...

  4. Breit-Wigner-Fano line shapes in Raman spectra of graphene

    E-Print Network [OSTI]

    Hasdeo, Eddwi H.

    Excitation of electron-hole pairs in the vicinity of the Dirac cone by the Coulomb interaction gives rise to an asymmetric Breit-Wigner-Fano line shape in the phonon Raman spectra in graphene. This asymmetric line shape ...

  5. UV Resonance Raman Spectroscopy Using a New cw Laser Source: Convenience and Experimental Simplicity

    E-Print Network [OSTI]

    Asher, Sanford A.

    into the spectrometer. We dem- onstrate the ability of this laser to excite Raman spectra of solid samples such as coal-liquid- alytical applications. Examples include studies of PAHs in coal-derived liquids4-~and in petroleum

  6. Vlasov simulations of kinetic enhancement of Raman backscatter in laser fusion plasmas

    E-Print Network [OSTI]

    Strozzi, D. J. (David J.)

    2006-01-01

    Stimulated Raman scattering (SRS) is studied in plasmas relevant to inertial confinement fusion (ICF). The Eulerian Vlasov-Maxwell code ELVIS was developed and run for this purpose. Plasma waves are heavily Landau damped ...

  7. Development of a Surface Enhanced Raman Spectroscopy Platform Technology to Detect Cardiac Biomarkers of Myocardial Infarction 

    E-Print Network [OSTI]

    Benford, Melodie Elane

    2013-04-24

    to include cardiac markers as central to diagnosis. To address this clinical need, a sensitive microfluidic surface-enhanced Raman spectroscopy (SERS) nanochannel-based optical device is being developed for ultimate use as a point-of-care device...

  8. Improving Raman velocimetry of laser-cooled cesium atoms by spin-polarization

    E-Print Network [OSTI]

    Julien Chabé; Hans Lignier; Pascal Szriftgiser; Jean Claude Garreau

    2007-02-04

    We study the peformances of Raman velocimetry applied to laser-cooled, spin-polarized, cesium atoms. Atoms are optically pumped into the F=4, m=0 ground-state Zeeman sublevel, which is insensitive to magnetic perturbations. High resolution Raman stimulated spectroscopy is shown to produce Fourier-limited lines, allowing, in realistic experimental conditions, atomic velocity selection to one-fiftieth of a recoil velocity.

  9. Glucose concentration measured by the hybrid coherent anti-Stokes Raman-scattering technique 

    E-Print Network [OSTI]

    Wang, Xi; Zhang, Aihua; Zhi, Miaochan; Sokolov, Alexei V.; Welch, George R.

    2010-01-01

    spectroscopy and coherent anti-Stokes Raman-scattering (CARS) spectroscopy find widespread use in medical diagnostics [3,4]. While the probability of spontaneous Raman scattering depends on the molecular concentration linearly, for its coherent counterpart?CARS...?the signal is known to scale quadrat- ically with the concentration of scatterers due to constructive interference of the resultant coherent photons [1,2]. In recent work, Dogariu et al. [5] have measured a clear quadratic dependence of the CARS signal...

  10. Raman Spectroscopy of DNA Packaging in Individual Human Sperm Cells distinguishes Normal from Abnormal Cells

    SciTech Connect (OSTI)

    Huser, T; Orme, C; Hollars, C; Corzett, M; Balhorn, R

    2009-03-09

    Healthy human males produce sperm cells of which about 25-40% have abnormal head shapes. Increases in the percentage of sperm exhibiting aberrant sperm head morphologies have been correlated with male infertility, and biochemical studies of pooled sperm have suggested that sperm with abnormal shape may contain DNA that has not been properly repackaged by protamine during spermatid development. We have used micro-Raman spectroscopy to obtain Raman spectra from individual human sperm cells and examined how differences in the Raman spectra of sperm chromatin correlate with cell shape. We show that Raman spectra of individual sperm cells contain vibrational marker modes that can be used to assess the efficiency of DNA-packaging for each cell. Raman spectra obtained from sperm cells with normal shape provide evidence that DNA in these sperm is very efficiently packaged. We find, however, that the relative protein content per cell and DNA packaging efficiencies are distributed over a relatively wide range for sperm cells with both normal and abnormal shape. These findings indicate that single cell Raman spectroscopy should be a valuable tool in assessing the quality of sperm cells for in-vitro fertilization.

  11. Development of time-domain differential Raman for transient thermal probing of materials

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Xu, Shen; Wang, Tianyu; Hurley, David; Yue, Yanan; Wang, Xinwei

    2015-01-01

    A novel transient thermal characterization technology is developed based on the principles of transient optical heating and Raman probing: time-domain differential Raman. It employs a square-wave modulated laser of varying duty cycle to realize controlled heating and transient thermal probing. Very well defined extension of the heating time in each measurement changes the temperature evolution profile and the probed temperature field at ?s resolution. Using this new technique, the transient thermal response of a tipless Si cantilever is investigated along the length direction. A physical model is developed to reconstruct the Raman spectrum considering the temperature evolution, while taking intomore »account the temperature dependence of the Raman emission. By fitting the variation of the normalized Raman peak intensity, wavenumber, and peak area against the heating time, the thermal diffusivity is determined as 9.17 × 10??, 8.14 × 10??, and 9.51 × 10?? m²/s. These results agree well with the reference value of 8.66 × 10?? m²/s considering the 10% fitting uncertainty. The time-domain differential Raman provides a novel way to introduce transient thermal excitation of materials, probe the thermal response, and measure the thermal diffusivity, all with high accuracy.« less

  12. Development of time-domain differential Raman for transient thermal probing of materials

    SciTech Connect (OSTI)

    Xu, Shen; Wang, Tianyu; Hurley, David; Yue, Yanan; Wang, Xinwei

    2015-01-01

    A novel transient thermal characterization technology is developed based on the principles of transient optical heating and Raman probing: time-domain differential Raman. It employs a square-wave modulated laser of varying duty cycle to realize controlled heating and transient thermal probing. Very well defined extension of the heating time in each measurement changes the temperature evolution profile and the probed temperature field at ?s resolution. Using this new technique, the transient thermal response of a tipless Si cantilever is investigated along the length direction. A physical model is developed to reconstruct the Raman spectrum considering the temperature evolution, while taking into account the temperature dependence of the Raman emission. By fitting the variation of the normalized Raman peak intensity, wavenumber, and peak area against the heating time, the thermal diffusivity is determined as 9.17 × 10??, 8.14 × 10??, and 9.51 × 10?? m²/s. These results agree well with the reference value of 8.66 × 10?? m²/s considering the 10% fitting uncertainty. The time-domain differential Raman provides a novel way to introduce transient thermal excitation of materials, probe the thermal response, and measure the thermal diffusivity, all with high accuracy.

  13. Raman induced soliton self-frequency shift in microresonator Kerr frequency combs

    E-Print Network [OSTI]

    Karpov, Maxim; Kordts, Arne; Brasch, Victor; Pfeiffer, Martin; Zervas, Michail; Geiselmann, Michael; Kippenberg, Tobias J

    2015-01-01

    The formation of temporal dissipative solitons in continuous wave laser driven microresonators enables the generation of coherent, broadband and spectrally smooth optical frequency combs as well as femtosecond pulses with compact form factor. Here we report for the first time on the observation of a Raman-induced soliton self-frequency shift for a microresonator soliton. The Raman effect manifests itself in amorphous SiN microresonator based single soliton states by a spectrum that is hyperbolic secant in shape, but whose center is spectrally red-shifted (i.e. offset) from the continuous wave pump laser. The Raman induced spectral red-shift is found to be tunable via the pump laser detuning and grows linearly with peak power. The shift is theoretically described by the first order shock term of the material's Raman response, and we infer a Raman shock time of 20 fs for amorphous SiN. Moreover, we observe that the Raman induced frequency shift can lead to a cancellation or overcompensation of the soliton recoi...

  14. Analysis of Doppler Lidar Data Acquired During the Pentagon Shield Field Campaign

    SciTech Connect (OSTI)

    Newsom, Rob K. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2011-04-14

    Observations from two coherent Doppler lidars deployed during the Pentagon Shield field campaign are analyzed in conjunction with other sensors to characterize the overall boundary-layer structure, and identify the dominant flow characteristics during the entire two-week field campaign. Convective boundary layer (CBL) heights and cloud base heights (CBH) are estimated from an analysis of the lidar signal-to-noise-ratio (SNR), and mean wind profiles are computed using a modified velocity-azimuth-display (VAD) algorithm. Three-dimensional wind field retrievals are computed from coordinated overlapping volume scans, and the results are analyzed by visualizing the flow in horizontal and vertical cross sections. The VAD winds show that southerly flows dominate during the two-week field campaign. Low-level jets (LLJ) were evident on all but two of the nights during the field campaign. The LLJs tended to form a couple hours after sunset and reach maximum strength between 03 and 07 UTC. The surface friction velocities show distinct local maxima during four nights when strong LLJs formed. Estimates of the convective boundary layer height and residual layer height are obtained through an analysis of the vertical gradient of the lidar signal-to-noise-ratio (SNR). Strong minimum in the SNR gradient often develops just above the surface after sunrise. This minimum is associated with the developing CBL, and increases rapidly during the early portion of the daytime period. On several days, this minimum continues to increase until about sunset. Secondary minima in the SNR gradient were also observed at higher altitudes, and are believed to be remnants of the CBL height from previous days, i.e. the residual layer height. The dual-Doppler analysis technique used in this study makes use of hourly averaged radial velocity data to produce three-dimensional grids of the horizontal velocity components, and the horizontal velocity variance. Visualization of horizontal and vertical cross sections of the dual-Doppler wind retrievals often indicated a jet-like flow feature over the Potomac River under southerly flow conditions. This linear flow feature is roughly aligned with the Potomac River corridor to the south of the confluence with the Anatostia River, and is most apparent at low levels (i.e. below ~150 m MSL). It is believed that this flow arises due to reduced drag over the water surface and when the large scale flow aligns with the Potomac River corridor. A so-called area-constrained VAD analysis generally confirmed the observations from the dual-Doppler analysis. When the large scale flow is southerly, wind speeds over the Potomac River are consistently larger than the at a site just to the west of the river for altitudes less than 100 m MSL. Above this level, the trend is somewhat less obvious. The data suggest that the depth of the wind speed maximum may be reduced by strong directional shear aloft.

  15. Raman Spectroscopic and Visible Absorption Investigation of LiCrSi2O6 Pyroxene Under Pressure

    E-Print Network [OSTI]

    Downs, Robert T.

    , changes in the Raman spectra are observed between 6.8 and 7.7 GPa, possibly due to the formation for these changes have been the subject of much study.2 A recently discovered phase transition in Mg­Fe rich in the P21/c phase. By factor-group analysis, there should be 30 Raman-active Ag modes and 30 Raman

  16. A compact double-pass Raman backscattering amplifier/compressor

    SciTech Connect (OSTI)

    Ren, J.; Li, S.; Morozov, A.; Suckewer, S.; Yampolsky, N. A.; Malkin, V. M.; Fisch, N. J.

    2008-05-15

    The enhancement of stimulated Raman backscattering (SRBS) amplification was demonstrated by introducing a plasma density gradient along the pump and the seed interaction path and by a novel double-pass design. The energy transfer efficiency was significantly improved to a level of 6.4%. The seed pulse was amplified by a factor of more than 20 000 from the input in a 2 mm long plasma, which also exceeded the intensity of the pump pulse by 2 orders of magnitude. This was accompanied by very effective pulse compression, from 500 fs to 90 fs in the first pass measurements and in the second pass down to approximately 50 fs, as it is indicated by the energy-pulse duration relation. Further improvements to the energy transfer efficiency and the SRBS performance by extending the region of resonance is also discussed where a uniform {approx}4 mm long plasma channel for SRBS was generated by using two subsequent laser pulses in an ethane gas jet.

  17. Measuring depth profiles of residual stress with Raman spectroscopy

    SciTech Connect (OSTI)

    Enloe, W.S.; Sparks, R.G.; Paesler, M.A.

    1988-12-01

    Knowledge of the variation of residual stress is a very important factor in understanding the properties of machined surfaces. The nature of the residual stress can determine a part`s susceptibility to wear deformation, and cracking. Raman spectroscopy is known to be a very useful technique for measuring residual stress in many materials. These measurements are routinely made with a lateral resolution of 1{mu}m and an accuracy of 0.1 kbar. The variation of stress with depth; however, has not received much attention in the past. A novel technique has been developed that allows quantitative measurement of the variation of the residual stress with depth with an accuracy of 10nm in the z direction. Qualitative techniques for determining whether the stress is varying with depth are presented. It is also demonstrated that when the stress is changing over the volume sampled, errors can be introduced if the variation of the stress with depth is ignored. Computer aided data analysis is used to determine the depth dependence of the residual stress.

  18. Light trapping in thin-film solar cells measured by Raman spectroscopy

    SciTech Connect (OSTI)

    Ledinský, M., E-mail: ledinsky@fzu.cz [Laboratory of Nanostructures and Nanomaterials, Institute of Physics, Academy of Sciences of the Czech Republic, v. v. i., Cukrovarnická 10, 162 00 Prague (Czech Republic); Photovoltaics and Thin Film Electronics Laboratory, Institute of Microengineering (IMT), École Polytechnique Fédérale de Lausanne (EPFL), Rue de la Maladière 71b, CH-2000 Neuchâtel (Switzerland); Moulin, E.; Bugnon, G.; Meillaud, F.; Ballif, C. [Photovoltaics and Thin Film Electronics Laboratory, Institute of Microengineering (IMT), École Polytechnique Fédérale de Lausanne (EPFL), Rue de la Maladière 71b, CH-2000 Neuchâtel (Switzerland); Ganzerová, K.; Vetushka, A.; Fejfar, A. [Laboratory of Nanostructures and Nanomaterials, Institute of Physics, Academy of Sciences of the Czech Republic, v. v. i., Cukrovarnická 10, 162 00 Prague (Czech Republic)

    2014-09-15

    In this study, Raman spectroscopy is used as a tool to determine the light-trapping capability of textured ZnO front electrodes implemented in microcrystalline silicon (?c-Si:H) solar cells. Microcrystalline silicon films deposited on superstrates of various roughnesses are characterized by Raman micro-spectroscopy at excitation wavelengths of 442?nm, 514?nm, 633?nm, and 785?nm, respectively. The way to measure quantitatively and with a high level of reproducibility the Raman intensity is described in details. By varying the superstrate texture and with it the light trapping in the ?c-Si:H absorber layer, we find significant differences in the absolute Raman intensity measured in the near infrared wavelength region (where light trapping is relevant). A good agreement between the absolute Raman intensity and the external quantum efficiency of the ?c-Si:H solar cells is obtained, demonstrating the validity of the introduced method. Applications to thin-film solar cells, in general, and other optoelectronic devices are discussed.

  19. The effects of machine parameters on residual stress determined using micro-Raman spectroscopy

    SciTech Connect (OSTI)

    Sparks, R.G.; Enloe, W.S.; Paesler, M.A.

    1988-12-01

    The effects of machine parameters on residual stresses in single point diamond turned silicon and germanium have been investigated using micro-Raman spectroscopy. Residual stresses were sampled across ductile feed cuts in < 100 > silicon and germanium which were single point diamond turned using a variety of feed rates, rake angles and clearance angles. High spatial resolution micro-Raman spectra (1{mu}m spot) were obtained in regions of ductile cutting where no visible surface damage was present. The use of both 514-5nm and 488.0nm excitation wavelengths, by virtue of their differing characteristic penetration depths in the materials, allowed determinations of stress profiles as a function of depth into the sample. Previous discussions have demonstrated that such Raman spectra will exhibit asymmetrically broadened peaks which are characteristic of the superposition of a continuum of Raman scatterers from the various depths probed. Depth profiles of residual stress were obtained using computer deconvolution of the resulting asymmetrically broadened raman spectra.

  20. Coherent Raman and Infrared Studies of Sulfur Trioxide

    SciTech Connect (OSTI)

    Chrysostom, Engelene; Vulpanovici, Nicolae; Masiello, Anthony; Barber, Jeffrey B.; Nibler, Joseph W.; Weber, Alfons; Maki, Arthur; Blake, Thomas A.

    2001-07-02

    High resolution (0.001 cm-1) coherent anti-Stokes Raman scattering (CARS) was used to observe the Q-branch structure of the IR-inactive n1 symmetric stretching mode of 32S 16O3 and its various 18O isotopomers. The v1 spectrum of 32S 16O3 reveals two intense Q-branch regions in the 1065-1067 cm-1 region, with surprisingly complex vibrational-rotational structure not resolved in earlier studies. Efforts to simulate this with a simple Fermi-resonance model involving v1 and 2v4 do not reproduce the spectral detail nor yield reasonable spectroscopic parameters. A more subtle combination of Fermi resonance and indirect Coriolis interactions with nearby states; 2v4 (l = 0, ? 2), v2+v4 (l = ? 1), 2v2 (l =0) is suspected and a determination of the location of these coupled states by high resolution infrared measurements is underway. At medium resolution (0.125 cm-1), the infrared spectra reveal Q-branch features from which approximate band origins are estimated for the v2, v3, v4 fundamental modes of 32S 18O3, 32S 18O2 16O and 32S 18O 16O2. These and literature data for 32S 16O3 are used to calculate force constants for SO3 and a comparison is made with similar values for SO2 and SO. The frequencies and force constants are in excellent agreement with a recent ab initio calculation by Martin. *In memory of Dr. Nicolae Vulpanovici (1968-2001)

  1. A digital map of the high center (HC) and low center (LC) polygon boundaries delineated from high resolution LiDAR data for Barrow, Alaska

    SciTech Connect (OSTI)

    Gangodagamage, Chandana; Wullschleger, Stan

    2014-07-03

    This dataset represent a map of the high center (HC) and low center (LC) polygon boundaries delineated from high resolution LiDAR data for the arctic coastal plain at Barrow, Alaska. The polygon troughs are considered as the surface expression of the ice-wedges. The troughs are in lower elevations than the interior polygon. The trough widths were initially identified from LiDAR data, and the boundary between two polygons assumed to be located along the lowest elevations on trough widths between them.

  2. A digital map of the high center (HC) and low center (LC) polygon boundaries delineated from high resolution LiDAR data for Barrow, Alaska

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Gangodagamage, Chandana; Wullschleger, Stan

    This dataset represent a map of the high center (HC) and low center (LC) polygon boundaries delineated from high resolution LiDAR data for the arctic coastal plain at Barrow, Alaska. The polygon troughs are considered as the surface expression of the ice-wedges. The troughs are in lower elevations than the interior polygon. The trough widths were initially identified from LiDAR data, and the boundary between two polygons assumed to be located along the lowest elevations on trough widths between them.

  3. Heterodyne coherent anti-Stokes Raman scattering by the phase control of its intrinsic background

    SciTech Connect (OSTI)

    Wang Xi; Wang Kai; Welch, George R.; Sokolov, Alexei V.

    2011-08-15

    We demonstrate the use of femtosecond laser pulse shaping for precise control of the interference between the coherent anti-Stokes Raman scattering (CARS) signal and the coherent nonresonant background generated within the same sample volume. Our technique is similar to heterodyne detection with the coherent background playing the role of the local oscillator field. In our experiment, we first apply two ultrashort (near-transform-limited) femtosecond pump and Stokes laser pulses to excite coherent molecular oscillations within a sample. After a short and controllable delay, we then apply a laser pulse that scatters off of these oscillations to produce the CARS signal. By making fine adjustments to the probe field spectral profile, we vary the relative phase between the Raman-resonant signal and the nonresonant background, and we observe a varying spectral interference pattern. These controlled variations of the measured pattern reveal the phase information within the Raman spectrum.

  4. Infrared and Raman spectra, DFT-calculations and spectral assignments of germacyclohexane

    SciTech Connect (OSTI)

    Aleksa, V. Ozerenskis, D.; Pucetaite, M.; Sablinskas, V.; Cotter, C.; Guirgis, G. A.

    2015-03-30

    Raman spectra of germacyclohexane in liquid and solid states were recorded and depolarization data obtained. Infrared absorption spectra of the vapor and liquid have been studied. The wavenumbers of the vibrational modes were derived in the harmonic and anharmonic approximation in B3LYP/ccpVTZ calculations. According to the calculations, germacyclohexane exists in the stable chair conformation, whereas a possible twist form should have more than 15?kJ·mol{sup -1} higher enthalpy of formation what makes this conformer experimentally not observable. The 27 A' and 21 A'' fundamentals were assigned on the basis of the calculations and infrared and Raman band intensities, contours of gas phase infrared spectral bands and Raman depolarization measurements. An average discrepancy of ca. 0.77 % was found between the observed and the calculated anharmonic wavenumbers for the 48 modes. Substitution of carbon atom with Ge atom in the cyclohexane ring is reasoning flattening of the ring.

  5. Quantitative, Comparable Coherent Anti-Stokes Raman Scattering (CARS) Spectroscopy: Correcting Errors in Phase Retrieval

    E-Print Network [OSTI]

    Camp, Charles H; Cicerone, Marcus T

    2015-01-01

    Coherent anti-Stokes Raman scattering (CARS) microspectroscopy has demonstrated significant potential for biological and materials imaging. To date, however, the primary mechanism of disseminating CARS spectroscopic information is through pseudocolor imagery, which explicitly neglects a vast majority of the hyperspectral data. Furthermore, current paradigms in CARS spectral processing do not lend themselves to quantitative sample-to-sample comparability. The primary limitation stems from the need to accurately measure the so-called nonresonant background (NRB) that is used to extract the chemically-sensitive Raman information from the raw spectra. Measurement of the NRB on a pixel-by-pixel basis is a nontrivial task; thus, reference NRB from glass or water are typically utilized, resulting in error between the actual and estimated amplitude and phase. In this manuscript, we present a new methodology for extracting the Raman spectral features that significantly suppresses these errors through phase detrending ...

  6. Facile residue analysis of recent and prehistoric cook-stones using handheld Raman spectrometry

    E-Print Network [OSTI]

    Short, Laura; Cao, Bin; Sinyukov, Alexander M; Joshi, Amitabh; Scully, Rob; Sanders, Virgil; Voronine, Dmitri V

    2013-01-01

    We performed food residue analysis of cook-stones from experimental and prehistoric earth ovens using a handheld Raman spectrometry. Progress in modern optical technology provides a facile means of rapid non-destructive identification of residue artifacts from archaeological sites. For this study spectral signatures were obtained on sotol (Dasylirion spp.) experimentally baked in an earth oven as well as sotol residue on an experimentally used processing tool. Inulin was the major residue component. The portable handheld Raman spectrometer also detected traces of inulin on boiling stones used to boil commercially obtained inulin. The Raman spectra of inulin and sotol may be useful as signatures of wild plant residues in archaeology. Spectroscopic analysis of millennia-old cook-stones from prehistoric archaeological sites in Fort Hood, TX revealed the presence of residues whose further identification requires improvement of current optical methods.

  7. Evolution of the Raman spectra from single-, few-, and many-layer graphene with increasing disorder

    SciTech Connect (OSTI)

    Martins Ferreira, E. H.; Stavale, F. [Divisao de Metrologia de Materiais, Instituto Nacional de Metrologia, Normalizacao e Qualidade Industrial (INMETRO), Duque de Caxias 25250-020, RJ (Brazil); Moutinho, Marcus V. O. [Instituto de Fisica, Universidade Federal do Rio de Janeiro, Cx. Postal 68528, Rio de Janeiro 21941-972, RJ (Brazil); Lucchese, M. M. [Divisao de Metrologia de Materiais, Instituto Nacional de Metrologia, Normalizacao e Qualidade Industrial (INMETRO), Duque de Caxias 25250-020, RJ (Brazil); Centro de Ciencias Exatas e Tecnologicas, Universidade Federal do Pampa, Bage, Rio Grande do Sul (Brazil); Capaz, Rodrigo B. [Divisao de Metrologia de Materiais, Instituto Nacional de Metrologia, Normalizacao e Qualidade Industrial (INMETRO), Duque de Caxias 25250-020, RJ (Brazil); Instituto de Fisica, Universidade Federal do Rio de Janeiro, Cx. Postal 68528, Rio de Janeiro 21941-972, RJ (Brazil); Achete, C. A. [Divisao de Metrologia de Materiais, Instituto Nacional de Metrologia, Normalizacao e Qualidade Industrial (INMETRO), Duque de Caxias 25250-020, RJ (Brazil); Programa de Engenharia Metalurgica e de Materiais (PEMM), Universidade Federal do Rio de Janeiro, Cx. Postal 68505, Rio de Janeiro 21945-970, RJ (Brazil); Jorio, A. [Divisao de Metrologia de Materiais, Instituto Nacional de Metrologia, Normalizacao e Qualidade Industrial (INMETRO), Duque de Caxias 25250-020, RJ (Brazil); Depto. de Fisica, Universidade Federal de Minas Gerais, Belo Horizonte 30123-970, MG (Brazil)

    2010-09-15

    We report on the micro-Raman spectroscopy of monolayer, bilayer, trilayer, and many layers of graphene (graphite) bombarded by low-energy argon ions with different doses. The evolution of peak frequencies, intensities, linewidths, and areas of the main Raman bands of graphene is analyzed as function of the distance between defects and number of layers. We describe the disorder-induced frequency shifts and the increase in the linewidth of the Raman bands by means of a spatial-correlation model. Also, the evolution of the relative areas A{sub D}/A{sub G}, A{sub D}{sup '}/A{sub G}, and A{sub G}{sup '}/A{sub G} is described by a phenomenological model. The present results can be used to fully characterize disorder in graphene systems.

  8. Synthesis of few layer graphene by direct exfoliation of graphite and a Raman spectroscopic study

    SciTech Connect (OSTI)

    Gayathri, S.; Jayabal, P.; Ramakrishnan, V., E-mail: vr.optics1@gmail.com [Department of Laser Studies, School of Physics, Madurai Kamaraj University, Madurai-625021, India. (India); Kottaisamy, M. [Department of Chemistry, Thiagarajar College of Engineering, Madurai-625015, India. (India)] [Department of Chemistry, Thiagarajar College of Engineering, Madurai-625015, India. (India)

    2014-02-15

    The exfoliation of graphene from pristine graphite in a liquid phase was achieved successfully via sonication followed by centrifugation method. Ultraviolet–visible (UV–vis) spectra of the obtained graphene dispersions at different exfoliation time indicated that the concentration of graphene dispersion increased markedly with increasing exfoliation time. The sheet-like morphology of the exfoliated graphene was revealed by Scanning Electron Microscopy (SEM) image. Further, the morphological change in different exfoliation time was investigated by Atomic Force Microscopy (AFM). A complete structural and defect characterization was probed using micro-Raman spectroscopic technique. The shape and position of the 2D band of Raman spectra revealed the formation of bilayer to few layer graphene. Also, Raman mapping confirmed the presence of uniformly distributed bilayer graphene sheets on the substrate.

  9. Feshbach-resonant Raman photoassociation in a Bose-Einstein condensate

    SciTech Connect (OSTI)

    Mackie, Matt; Phou, Pierre; Shinn, Mannix; Boyce, Heather; Katz, Lev

    2011-10-15

    We model the formation of stable heteronuclear molecules via pulsed Raman photoassociation of a two-component Bose-Einstein condensate near a strong Feshbach resonance, for both counterintuitive and intuitive pulse sequencing. Compared to lasers alone, weak Raman photoassociation is enhanced by as much as a factor of ten (five) for a counterintuitive (intuitive) pulse sequence, whereas strong Raman photoassociation is barely enhanced at all--regardless of pulse sequence. Stronger intra-atom, molecule, or atom-molecule collisions lead to an expected decrease in conversion efficiency, but stronger ambient inter-atom collisions lead to an unexpected increase in the efficiency of stable molecule production. Numerical results agree reasonably with an analytical approximation.

  10. Portable microfluidic raman system for rapid, label-free early disease signature detection

    SciTech Connect (OSTI)

    Wu, Meiye; Davis, Ryan Wesley; Hatch, Anson

    2015-09-01

    In the early stages of infection, patients develop non-specific or no symptoms at all. While waiting for identification of the infectious agent, precious window of opportunity for early intervention is lost. The standard diagnostics require affinity reagents and sufficient pathogen titers to reach the limit of detection. In the event of a disease outbreak, triaging the at-risk population rapidly and reliably for quarantine and countermeasure is more important than the identification of the pathogen by name. To expand Sandia's portfolio of Biological threat management capabilities, we will utilize Raman spectrometry to analyze immune subsets in whole blood to rapidly distinguish infected from non-infected, and bacterial from viral infection, for the purpose of triage during an emergency outbreak. The goal of this one year LDRD is to determine whether Raman spectroscopy can provide label-free detection of early disease signatures, and define a miniaturized Raman detection system meeting requirements for low- resource settings.

  11. Isotopic hydrogen analysis via conventional and surface-enhanced fiber optic Raman spectroscopy

    SciTech Connect (OSTI)

    LASCOLA, ROBERT

    2004-09-23

    This report describes laboratory development and process plant applications of Raman spectroscopy for detection of hydrogen isotopes in the Tritium Facilities at the Savannah River Site (SRS), a U.S. Department of Energy complex. Raman spectroscopy provides a lower-cost, in situ alternative to mass spectrometry techniques currently employed at SRS. Using conventional Raman and fiber optics, we have measured, in the production facility glove boxes, process mixtures of protium and deuterium at various compositions and total pressures ranging from 1000-4000 torr, with detection limits ranging from 1-2 percent for as low as 3-second integration times. We are currently investigating fabrication techniques for SERS surfaces in order to measure trace (0.01-0.1 percent) amounts of one isotope in the presence of the other. These efforts have concentrated on surfaces containing palladium, which promotes hydrogen dissociation and forms metal hydride bonds, essentially providing a chemical enhancement mechanism.

  12. Picosecond Time-Resolved Fourier Transform Raman Spectroscopy of 9,10-Diphenylanthracene in the Excited Singlet State

    E-Print Network [OSTI]

    Jas, Gouri S.; Wan, Chaozhi; Johnson, Carey K.

    1995-05-01

    resolution at several time delays between pump pulses at 355 nm and probe pulses at 1064 nm. The near-infrared excited-state Raman scattering is enhanced by resonance with an excited-state transition of DPA. The excited-state Raman bands decay in about 5-6 ns...

  13. Biochemical signatures of in vitro radiation response in human lung, breast and prostate tumour cells observed with Raman spectroscopy

    E-Print Network [OSTI]

    Brolo, Alexandre G.

    cells observed with Raman spectroscopy This article has been downloaded from IOPscience. Please scroll down to see the full text article. 2011 Phys. Med. Biol. 56 6839 (http://iopscience.iop.org/0031 signatures of in vitro radiation response in human lung, breast and prostate tumour cells observed with Raman

  14. Inverse Raman scattering in silicon: A free-carrier enhanced effect D. R. Solli, P. Koonath, and B. Jalali

    E-Print Network [OSTI]

    Jalali. Bahram

    , actually facilitates IRS by delaying the onset of contamination from coherent anti-Stokes Raman scattering with blueshifted anti-Stokes waves through a process known as coherent anti-Stokes Raman scattering CARS . Under . Since IRS occurs at the anti-Stokes wavelength, it avoids fluorescence contamination 7,9 . Apart from

  15. 58 IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT, VOL. 53, NO. 1, FEBRUARY 2004 Multichannel Raman Gas Analyzer: The Data

    E-Print Network [OSTI]

    Athens, University of

    with the green laser source previously used and reported in a related article. Index Terms--Air-pollution, data the above-listed is the Raman method, which is used for si- multaneous monitoring of a number of air pollutants in the multichannel Raman gas sensor (MRGS) device recently conceived and realized by the authors

  16. DOI: 10.1002/chem.201002027 Surface-Enhanced Raman Scattering of Single-and Few-Layer Graphene by

    E-Print Network [OSTI]

    Kim, Bongsoo

    DOI: 10.1002/chem.201002027 Surface-Enhanced Raman Scattering of Single- and Few-Layer Graphene*[a] Introduction Raman spectroscopy has been utilized as a powerful tool for the characterization of graphene and any defects in the graphene.[1] A Si substrate with a metal oxide layer of a specific thick- ness has

  17. June 1983 / Vol. 8, No. 6 / OPTICS LETTERS 295 Coherent anti-Stokes Raman scattering in thin-film dielectric

    E-Print Network [OSTI]

    Sipe,J. E.

    June 1983 / Vol. 8, No. 6 / OPTICS LETTERS 295 Coherent anti-Stokes Raman scattering in thin-film analyze coherent anti-Stokes Raman scattering in thin-film dielectric waveguides. Extraordinarily large enhancements can be obtained in films and at surfaces by coupling externally incident radiation fields to local

  18. Observation of ion wave decay products of Langmuir waves generated by stimulated Raman scattering in ignition scale plasmas

    E-Print Network [OSTI]

    Geddes, Cameron Guy Robinson

    Observation of ion wave decay products of Langmuir waves generated by stimulated Raman scattering the time resolved spectrum of ion wave decay products from two instabilities which can limit the growth of stimulated Raman scattering SRS . This experiment detected ion wave decay products far above the thermal

  19. 382 JOURNAL OF LIGHTWAVE TECHNOLOGY, VOL. 22, NO. 2, FEBRUARY 2004 Effect of a Raman Co-Pump's RIN on the BER

    E-Print Network [OSTI]

    Lakoba, Taras I.

    382 JOURNAL OF LIGHTWAVE TECHNOLOGY, VOL. 22, NO. 2, FEBRUARY 2004 Effect of a Raman Co-Pump's RIN from a Raman co-pump, on the bit-error rate (BER). We show that a given amount of the transferred RIN spontaneous emission (ASE) noise, than erbium amplifiers. The backward-pumping scheme, where the Raman pump

  20. High-resolution inverse Raman and resonant-wave-mixing spectroscopy

    SciTech Connect (OSTI)

    Rahn, L.A. [Sandia National Laboratories, Livermore, CA (United States)

    1993-12-01

    These research activities consist of high-resolution inverse Raman spectroscopy (IRS) and resonant wave-mixing spectroscopy to support the development of nonlinear-optical techniques for temperature and concentration measurements in combustion research. Objectives of this work include development of spectral models of important molecular species needed to perform coherent anti-Stokes Raman spectroscopy (CARS) measurements and the investigation of new nonlinear-optical processes as potential diagnostic techniques. Some of the techniques being investigated include frequency-degenerate and nearly frequency-degenerate resonant four-wave-mixing (DFWM and NDFWM), and resonant multi-wave mixing (RMWM).

  1. Cooling in reduced period optical lattices: non-zero Raman detuning

    E-Print Network [OSTI]

    V. S. Malinovsky; P. R. Berman

    2006-05-06

    In a previous paper [Phys. Rev. A 72, 033415 (2005)], it was shown that sub-Doppler cooling occurs in a standing-wave Raman scheme (SWRS) that can lead to reduced period optical lattices. These calculations are extended to allow for non-zero detuning of the Raman transitions. New physical phenomena are encountered, including cooling to non-zero velocities, combinations of Sisyphus and "corkscrew" polarization cooling, and somewhat unusual origins of the friction force. The calculations are carried out in a semi-classical approximation and a dressed state picture is introduced to aid in the interpretation of the results.

  2. Probing inhomogeneous composition in core/shell nanowires by Raman spectroscopy

    SciTech Connect (OSTI)

    Amaduzzi, F.; Alarcón-Lladó, E.; Russo-Averchi, E.; Matteini, F.; Heiß, M.; Tütüncüoglu, G.; Conesa-Boj, S.; Fontcuberta i Morral, A.; Mata, M. de la; Arbiol, J.

    2014-11-14

    Due to its non-destructive and its micro-spatial resolution, Raman spectroscopy is a powerful tool for a rapid structural and compositional characterization of nanoscale materials. Here, by combining the compositional dependence of the Raman peaks with the existence of photonic modes in the nanowires, we address the composition inhomogeneities of Al{sub x}Ga{sub 1?x}As/GaAs core/shell structures. The experimental results are validated with complementary chemical composition maps of the nanowire cross-sections and finite-difference time-domain simulations of the photonic modes.

  3. Exploring the Saturation Levels of Stimulated Raman Scattering in the Absolute Regime

    SciTech Connect (OSTI)

    Michel, D. T. [LULI, UMR 7605 CNRS-Ecole Polytechnique-CEA-Universite Paris VI, 91128 Palaiseau cedex (France); CEA DAM DIF, F- 91297 Arpajon (France); Depierreux, S.; Tassin, V. [CEA DAM DIF, F- 91297 Arpajon (France); Stenz, C. [CELIA, Universite Bordeaux 1, 351 cours de la Liberation, 33405 Talence cedex (France); Labaune, C. [LULI, UMR 7605 CNRS-Ecole Polytechnique-CEA-Universite Paris VI, 91128 Palaiseau cedex (France)

    2010-06-25

    This Letter reports new experimental results that evidence the transition between the absolute and convective growth of stimulated Raman scattering (SRS). Significant reflectivities were observed only when the instability grows in the absolute regime. In this case, saturation processes efficiently limit the SRS reflectivity that is shown to scale linearly with the laser intensity, and the electron density and temperature. Such a scaling agrees with the one established by T. Kolber et al.[Phys. Fluids B 5, 138 (1993)] and B Bezzerides et al.[Phys. Rev. Lett. 70, 2569 (1993)], from numerical simulations where the Raman saturation is due to the coupling of electron plasma waves with ion waves dynamics.

  4. Determination of the paradihlorobenzene and paradibromobenzene solid solutions nanoparticles structure via Raman spectra

    E-Print Network [OSTI]

    Korshunov, M A

    2012-01-01

    We measured the small frequencies Raman spectrum of the paradihlorobenzene and paradihlorobenzene solid solution nanoparticles with the size about 100 nanometers. Values of frequencies of lines decrease. The size of nanoparticles was determined by the electronic microscope. Calculations of nanoparticles structure were done using the method of molecular dynamics and histograms of nanoparticles spectra were calculated via the Dyne's method. The result is that the Raman spectrum is the sum of spectra from the central part of the nanoparticle and superficial structures with smaller concentration of paradihlorobenzene.

  5. Raman Spectroscopy of UH3 from the Hydrogen Corrosion of Uranium

    SciTech Connect (OSTI)

    Smyrl, N. R.; Stowe, A. C.; Powell, G. L.

    2011-05-31

    Hydrogen reacts with a uranium surface to form a fine, pyrophoric metal power (UH{sub 3}). Few spectroscopic studies have been conducted to study this reaction. Advances in Raman spectroscopy permit the application of the Raman method to formally difficult areas of chemistry such as the hydrogen corrosion of uranium: availability of multiple laser excitation wavelengths; fiber optics delivery and collection systems; upgraded instrumentation and detection techniques; and development of special enclosed in situ reactor cells. UH{sub 3} vibrations are expected to occur at low frequencies due to extended U-H-U structure.

  6. Quantifying and relating land-surface and subsurface variability in permafrost environments using lidar and surface geophsical datasets

    SciTech Connect (OSTI)

    Hubbard, Susan S [Lawrence Berkeley National Laboratory (LBNL); Gangodagmage, C [Los Alamos National Laboratory (LANL); Dafflon, B [Lawrence Berkeley National Laboratory (LBNL); Wainwright, H [Lawrence Berkeley National Laboratory (LBNL); Peterson, J [Lawrence Berkeley National Laboratory (LBNL); Gusmeroli, A [University of Alaska, Fairbanks; Ulrich, Craig [Lawrence Berkeley National Laboratory (LBNL); Wu, Yuxin [Lawrence Berkeley National Laboratory (LBNL); Wilson, Cathy [Los Alamos National Laboratory (LANL); Rowland, J [Los Alamos National Laboratory (LANL); Tweedie, Craig [University of Texas, El Paso; Wullschleger, Stan D [ORNL

    2013-01-01

    The complexity of permafrost dynamics and its critical impact on climate feedbacks warrant continued development of advanced high-latitude terrestrial ecosystem characterization and monitoring approaches. In this study, we explore the value of remote sensing and surface geophysical data for characterizing land surface and subsurface properties and their linkages in an Alaskan Coastal Plain ecosystem. We base our study on data collected at the end of the 2011 growing season in the Barrow Environmental Observatory, where a nested suite of measurements were collected within a polygon-dominated region including: surface ground penetrating radar, electromagnetic, and electrical resistance tomography data; thaw depth, soil temperature and moisture content, soil texture, soil carbon and nitrogen content, and major and trace cations. Previously-collected lidar data were also available for the study. Analysis of the datasets, individually and in combination, revealed the utility of the methods for characterizing critical land-surface and subsurface properties and associated spatial zonation. Lidar analysis was performed to extract geomorphic metrics (such as slope, curvature, and directed distance of polygons), which potentially indicate drainage potential and permafrost deformation state. Cluster analysis of these lidar-obtained attributes suggested that the land surface can be grouped into three spatially coherent zones, each having a dominant geomorphic expression including: a high centered polygon zone, a low centered polygon zone and a transitional zone. Comparison of the geophysical attributes from radar, electrical resistance tomography, and electromagnetic data with point measurements suggests that the surface geophysical data can provide very high-resolution information about subsurface properties that affect ecosystem feedbacks to climate, such as thaw depth and moisture content. Cluster analysis suggested that the geophysical attributes also varied spatially in a systematic way, suggesting the presence of three laterally distinct subsurface zones. Analysis of zone-based subsurface point measurements suggests that the geophysically-defined zones have unique distributions of hydrological, thermal, and geochemical properties and that the subsurface (geophysically-based) and land-surface (lidar-based) zonation is consistent. Although the close linkage between land surface (polygonal geomorphology) and subsurface (active layer) variability revealed through our study is not surprising, to our knowledge this is the first study to document such relationships using high resolution and non-invasive approaches. This study suggests the potential of using coincident lidar and surface geophysical measurements to quantify land surface and subsurface properties (respectively) and their linkages, which are likely to play a role in terrestrial ecosystem evolution and feedbacks to climate. These findings open the way for future research focused on using combined geophysical and remote sensing datasets to estimate subsurface and land-surface properties in high resolution and over large regions as is needed for process understanding and numerical model initialization in high latitude terrestrial ecosystems.

  7. The probability of laser caused ocular injury to the aircrew of undetected aircraft violating the exclusion zone about the airborne aura LIDAR.

    SciTech Connect (OSTI)

    Augustoni, Arnold L.

    2006-12-01

    The probability of a laser caused ocular injury, to the aircrew of an undetected aircraft entering the exclusion zone about the AURA LIDAR airborne platform with the possible violation of the Laser Hazard Zone boundary, was investigated and quantified for risk analysis and management.

  8. Using LiDAR, Aerial Photography, and Geospatial Technologies to Reveal and Understand Past Landscapes in Four West Central Missouri Counties

    E-Print Network [OSTI]

    Price, R. Zane

    2012-05-31

    . Each sensor offers unique advantages and disadvantages due to the design and construction of the sensor. LiDAR can strip away vegetation to present a bare earth model (a DTM) of terrain, useful in the detection of features revealed by subtle elevation...

  9. JOURNAL OF GEOPHYSICAL RESEARCH, VOL. ???, XXXX, DOI:10.1029/, Combined lidar and sun-photometer retrievals of ash particle size and mass

    E-Print Network [OSTI]

    Hogan, Robin

    -photometer retrievals of ash particle size and mass concentration from the Eyjafjallaj¨okull volcano Robin J. Hogan,1 the need for lidar monitoring stations capa- ble of routinely estimating the vertical profile of ash mass to demonstrate that large errors are likely in methods that attempt to infer the properties of the ash from

  10. Deriving a Framework for Estimating Individual Tree Measurements with Lidar for Use in the TAMBEETLE Southern Pine Beetle Infestation Growth Model 

    E-Print Network [OSTI]

    Stukey, Jared D.

    2011-02-22

    , individual bole height (IBH), diameter at breast height (DBH), length of crown (CrHT), and age for use in TAMBEETLE; (2) to estimate individual tree age using lidar-estimated height and site index provided by the United States Department of Agriculture (USDA...

  11. 7 Plots of Biomass Burning and Dust Plumes This supplementary section shows curtain plots from the NASA Langley airborne High Spectral Resolution Lidar for

    E-Print Network [OSTI]

    Meskhidze, Nicholas

    7 Plots of Biomass Burning and Dust Plumes This supplementary section shows curtain plots from the NASA Langley airborne High Spectral Resolution Lidar for cases of fresh biomass burning plumes and dust: Curtain plots of HSRL backscatter coefficients and intensive properties for transects over fresh biomass

  12. Cloud fraction, liquid and ice water contents derived from long-term radar, lidar, and microwave radiometer data are systematically compared to models to quantify and

    E-Print Network [OSTI]

    Hogan, Robin

    Cloud fraction, liquid and ice water contents derived from long-term radar, lidar, and microwave a systematic evaluation of clouds in forecast models. Clouds and their associated microphysical processes for end users of weather forecasts, who may be interested not only in cloud cover, but in other variables

  13. LIDAR Wind Speed Measurement Analysis and Feed-Forward Blade Pitch Control for Load Mitigation in Wind Turbines: January 2010--January 2011

    SciTech Connect (OSTI)

    Dunne, F.; Simley, E.; Pao, L.Y.

    2011-10-01

    This report examines the accuracy of measurements that rely on Doppler LIDAR systems to determine their applicability to wind turbine feed-forward control systems and discusses feed-forward control system designs that use preview wind measurements. Light Detection and Ranging (LIDAR) systems are able to measure the speed of incoming wind before it interacts with a wind turbine rotor. These preview wind measurements can be used in feed-forward control systems designed to reduce turbine loads. However, the degree to which such preview-based control techniques can reduce loads by reacting to turbulence depends on how accurately the incoming wind field can be measured. The first half of this report examines the accuracy of different measurement scenarios that rely on coherent continuous-wave or pulsed Doppler LIDAR systems to determine their applicability to feed-forward control. In particular, the impacts of measurement range and angular offset from the wind direction are studied for various wind conditions. A realistic case involving a scanning LIDAR unit mounted in the spinner of a wind turbine is studied in depth with emphasis on choices for scan radius and preview distance. The effects of turbulence parameters on measurement accuracy are studied as well. Continuous-wave and pulsed LIDAR models based on typical commercially available units were used in the studies present in this report. The second half of this report discusses feed-forward control system designs that use preview wind measurements. Combined feedback/feed-forward blade pitch control is compared to industry standard feedback control when simulated in realistic turbulent above-rated winds. The feed-forward controllers are designed to reduce fatigue loads, increasing turbine lifetime and therefore reducing the cost of energy. Three feed-forward designs are studied: non-causal series expansion, Preview Control, and optimized FIR filter. The input to the feed-forward controller is a measurement of incoming wind speeds that could be provided by LIDAR. Non-causal series expansion and Preview Control methods reduce blade root loads but increase tower bending in simulation results. The optimized FIR filter reduces loads overall, keeps pitch rates low, and maintains rotor speed regulation and power capture, while using imperfect wind measurements provided by the spinning continuous-wave LIDAR model.

  14. Coherent anti-stokes Raman spectroscopy system for point temperature and major species concentration measurement

    SciTech Connect (OSTI)

    Singh, J.P.; Yueh, Fang-Yu

    1993-10-01

    The Coherent anti-Stokes Raman Spectroscopy system (CARS) has been developed as a laser-based, advanced, combustion-diagnostic technique to measure temperature and major species concentration. Principles of operation, description of the system and its capabilities, and operational details of this instrument are presented in this report.

  15. Design Considerations for a Portable Raman Probe Spectrometer for Field Forensics

    SciTech Connect (OSTI)

    Kelly, James F.; Blake, Thomas A.; Bernacki, Bruce E.; Johnson, Timothy J.

    2012-09-01

    Raman spectroscopy has been shown to be a viable method for explosives detection. Currently most forensic Raman systems are either large, powerful instruments for laboratory experiments or handheld instruments for in situ point detection. We have chosen to examine the performance of certain benchtop Raman probe systems with the goal of developing an inexpensive, portable system that could be used to operate in a field forensics laboratory to examine explosives-related residues or samples. To this end, a rugged, low distortion line imaging dispersive Raman spectrograph was configured to work at 830 nm laser excitation and was used to determine whether the composition of thin films of plastic explosives or small (e.g., ?10 ?m) particles of RDX or other explosives or oxidizers can be detected, identified, and quantified in the field. With 300mW excitation energy, concentrations of RDX and PETN can be detected and reconstructed in the case of thin Semtex smears, but further work is needed to push detection limits of areal dosages to the ?1 ?g/cm2 level.We describe the performance of several probe/spectrograph combinations and show preliminary data for particle detection, calibration and detection linearity for mixed compounds, and so forth.

  16. Detection of bacterial endospores by means of ultrafast coherent raman spectroscopy 

    E-Print Network [OSTI]

    Pestov, Dmitry Sergeyevich

    2008-10-10

    backscattered CARS signal from DPA and NaDPA powders. The possibility of selective Raman excitation via pulse shaping of the preparation pulses is also demonstrated. The analysis of time-resolved CARS experiments on powders and B. subtilis spores, a harmless...

  17. Developments in enzyme immobilization and near-infrared Raman spectroscopy with downstream renewable energy applications

    SciTech Connect (OSTI)

    Lupoi, Jason

    2012-08-27

    This dissertation focuses on techniques for (1) increasing ethanol yields from saccharification and fermentation of cellulose using immobilized cellulase, and (2) the characterization and classification of lignocellulosic feedstocks, and quantification of useful parameters such as the syringyl/guaiacyl (S/G) lignin monomer content using 1064 nm dispersive multichannel Raman spectroscopy and chemometrics.

  18. Raman spectra of out-of-plane phonons in bilayer graphene

    E-Print Network [OSTI]

    Sato, Kentaro

    The double resonance Raman spectra of the overtone of the out-of-plane tangential optical (oTO) phonon and of combinations of the LO, ZO, and ZA phonons with one another are calculated for bilayer graphene. In the case of ...

  19. Improving total column ozone retrievals by using cloud pressures derived from Raman scattering in the UV

    E-Print Network [OSTI]

    Joiner, Joanna

    Improving total column ozone retrievals by using cloud pressures derived from Raman scattering resolution, coverage, and sampling of the Aura satellite ozone monitoring instrument (OMI), as compared with the total ozone mapping spectrometer (TOMS) should allow for improved ozone retrievals. By default, the TOMS

  20. April 1, 1995 / Vol. 20, No. 7 / OPTICS LETTERS 791 Intracavity technique for improved Raman / Rayleigh

    E-Print Network [OSTI]

    Long, Marshall B.

    April 1, 1995 / Vol. 20, No. 7 / OPTICS LETTERS 791 Intracavity technique for improved Raman cavity is modified to include sheet-forming optics and 100% reflecting end mirrors. In a comparison of this system with a laser configuration with the sheet-forming optics outside the cavity, the beam waist

  1. Beyond Myopic Inference in Big Data Pipelines Karthik Raman, Adith Swaminathan, Johannes Gehrke, Thorsten Joachims

    E-Print Network [OSTI]

    Joachims, Thorsten

    Beyond Myopic Inference in Big Data Pipelines Karthik Raman, Adith Swaminathan, Johannes Gehrke,adith,johannes,tj}@cs.cornell.edu ABSTRACT Big Data Pipelines decompose complex analyses of large data sets into a series of simpler tasks different pipelines. However, the interaction of independently tuned pipeline components yields poor end

  2. Analysis of climate trends in North Carolina (19491998) Ryan P. Boyles*, Sethu Raman

    E-Print Network [OSTI]

    Raman, Sethu

    Analysis of climate trends in North Carolina (1949­1998) Ryan P. Boyles*, Sethu Raman State Climate Office of North Carolina, Department of Marine, Earth, and Atmospheric Sciences, North Carolina State University, Raleigh, NC 27695-7236, USA Abstract North Carolina has one of the most complex climates

  3. Topography-Correlated Confocal Raman Microscopy with Cylindrical Vector Beams for Probing Nanoscale Structural Order

    E-Print Network [OSTI]

    Schreiber, Frank

    Topography-Correlated Confocal Raman Microscopy with Cylindrical Vector Beams for Probing Nanoscale, such as radially or azimuthally polarized doughnut beams, are combined with topography studies of pentacene thin in the mirror focus and kept within a nanometer distance from the surface to probe the topography using shear

  4. Atomic force microscope with combined FTIR-Raman spectroscopy having a micro thermal analyzer

    DOE Patents [OSTI]

    Fink, Samuel D. (Aiken, SC); Fondeur, Fernando F. (North Augusta, SC)

    2011-10-18

    An atomic force microscope is provided that includes a micro thermal analyzer with a tip. The micro thermal analyzer is configured for obtaining topographical data from a sample. A raman spectrometer is included and is configured for use in obtaining chemical data from the sample.

  5. MODIFYING AN INVERTED LABORATORY MICROSCOPE FOR RAMAN Presented in Partial Fulfillment of the Requirements for

    E-Print Network [OSTI]

    that area to provide image contrast. Several different model systems were imaged with the Raman microscope by Professor Heather C. Allen, Advisor Professor Richard L. McCreery _________________________________ Advisor, but there are a few that deserve a special thank you. First of all, I would like to thank my advisor, Heather Allen

  6. Raman spectroscopy of carbon dust samples from NSTX Y. Raitses a,*, C.H. Skinner a

    E-Print Network [OSTI]

    Duffy, Thomas S.

    . The Raman measurements indicate that the production of carbon dust particles in NSTX involves modifications to be similar to those measured for carbon deposits from atmospheric pressure helium arc discharge responsible for dust production: (i) evap- oration and sublimation of thermally overloaded wall material

  7. Time-resolved x-ray Raman spectroscopy of photoexcited polydiacetylene oligomer: A simulation study

    E-Print Network [OSTI]

    Mukamel, Shaul

    , Osaka Prefecture University, Sakai 599-8531, Japan Sergei Volkov Department of Chemistry, University of the x-ray Raman peaks on the scattering wave vector k and energy . The electronic excitation energies progress in generating ultrafast x-ray pulses and bringing them down to the attosecond regime has opened up

  8. Practical substrate and apparatus for static and continuous monitoring by surface-enhanced raman spectroscopy

    DOE Patents [OSTI]

    Vo-Dinh, Tuan (Knoxville, TN)

    1987-01-01

    A substrate for use in surface-enhanced Raman spectroscopy (SERS) is disclosed, comprising a support, preferably flexible, coated with roughness-imparting microbodies and a metallized overcoating. Also disclosed is apparatus for using the aforesaid substrate in continuous and static SERS trace analyses, especially of organic compounds.

  9. JustSpeak: Enabling Universal Voice Control on Android , T.V. Raman2

    E-Print Network [OSTI]

    Cortes, Corinna

    JustSpeak: Enabling Universal Voice Control on Android Yu Zhong1 , T.V. Raman2 , Casey Burkhardt2 to the Android op- erating system. JustSpeak offers two contributions as compared to existing systems. First, it enables system wide voice control on Android that can accommodate any application. JustSpeak constructs

  10. Computer based pedestrian landscape design using decision tree templates Baranidharan Raman a,

    E-Print Network [OSTI]

    Raman, Barani

    Computer based pedestrian landscape design using decision tree templates Baranidharan Raman a. In this paper, we demonstrate the application of a decision tree learning algorithm for designing pedestrian that queried responses to cognitive, physical and social attributes that influence pedestrian spatial analysis

  11. In-situ Observation of Raman Scattering of SWNTs during ACCVD Process

    E-Print Network [OSTI]

    Maruyama, Shigeo

    Murakami, Yuhei Miyauchi and Shigeo Maruyama Department of Mechanical Engineering, The University of Tokyo) (c) (b) (a) Fig. 2 Raman scattering by SWNTs during ACCVD process. rotary pump & turbo monochromator quartz window detector laser (633 nm)filter rotary pump & turbo-molecular pump excitation laser

  12. Electrochemical Control of the Time-Dependent Intensity Fluctuations in Surface-Enhanced Raman Scattering (SERS)

    E-Print Network [OSTI]

    Brolo, Alexandre G.

    in surface-enhanced Raman scattering (SERS) intensities were recorded from a roughened silver electrode the applied potential. The potential-controlled distribution of SERS intensities was interpreted by considering the modulation of the surface coverage of the adsorbed dye by the interfacial electric field

  13. Micro-resonance Raman study of optically trapped Escherichia coli cells overexpressing human neuroglobin

    E-Print Network [OSTI]

    Wenseleers, Wim

    neuroglobin Kerstin Ramser Göteborgs University Department of Physics SE-412 96 Göteborg, Sweden and Luleå coli E. coli overexpressing wild type wt neuroglobin NGB and its E7Leu mutant, respectively. NGB. DOI: 10.1117/1.2753478 Keywords: E. coli bacteria; neuroglobin; E7Leu neuroglobin; resonance Raman

  14. Demonstration of triple pump coherent anti-Stokes Raman scattering in a jet diffusion flame 

    E-Print Network [OSTI]

    Velur Natarajan, Viswanathan

    2002-01-01

    Three pulsed narrow band pump sources (a frequency doubled pulsed Nd-YAG, and two narrow band dye lasers) and a broad-band Stokes laser source are used to demonstrate triple pump coherent anti-Stokes Raman scattering in a jet diffusion flame...

  15. MESOSCALE ANALYSIS OF A CAROLINA COASTAL FRONT SETHU RAMAN, NEERAJA C. REDDY and DEVDUTTA S. NIYOGI

    E-Print Network [OSTI]

    Niyogi, Dev

    MESOSCALE ANALYSIS OF A CAROLINA COASTAL FRONT SETHU RAMAN, NEERAJA C. REDDY and DEVDUTTA S. NIYOGI the shore. Key words: GALE, Coastal front, Atmospheric boundary layer, Gulf Stream, Mesoscale analysis turbulent heat fluxes. These strong gradients in heat fluxes enhance mesoscale circulation

  16. Hydrostatic pressure dependence of the luminescence and Raman frequencies in polyfluorene C. M. Martin,1

    E-Print Network [OSTI]

    Chandrasekhar, Meera

    , absorption, and Raman scattering spectra from poly 2,7-,,9,9 -bis(2-ethylhexyl)...fluorene under hydrostatic fabricated from the PF family of materials are known to degrade under operation. The desired blue elec,14 In this work we probe the optical properties of poly 2,7-,,9,9 -bis(2-ethylhexyl)...fluorene PF2/6 via PL

  17. Multidimensional resonance raman spectroscopy by six-wave mixing in the deep UV

    SciTech Connect (OSTI)

    Molesky, Brian P.; Giokas, Paul G.; Guo, Zhenkun; Moran, Andrew M.

    2014-09-21

    Two-dimensional (2D) resonance Raman spectroscopies hold great potential for uncovering photoinduced relaxation processes in molecules but are not yet widely applied because of technical challenges. Here, we describe a newly developed 2D resonance Raman experiment operational at the third-harmonic of a Titanium-Sapphire laser. High-sensitivity and rapid data acquisition are achieved by combining spectral interferometry with a background-free (six-pulse) laser beam geometry. The third-harmonic laser pulses are generated in a filament produced by the fundamental and second-harmonic pulses in neon gas at pressures up to 35 atm. The capabilities of the setup are demonstrated by probing ground-state wavepacket motions in triiodide. The information provided by the experiment is explored with two different representations of the signal. In one representation, Fourier transforms are carried out with respect to the two experimentally controlled delay times to obtain a 2D Raman spectrum. Further insights are derived in a second representation by dispersing the signal pulse in a spectrometer. It is shown that, as in traditional pump-probe experiments, the six-wave mixing signal spectrum encodes the wavepacket's position by way of the (time-evolving) emission frequency. Anharmonicity additionally induces dynamics in the vibrational resonance frequency. In all cases, the experimental signals are compared to model calculations based on a cumulant expansion approach. This study suggests that multi-dimensional resonance Raman spectroscopies conducted on systems with Franck-Condon active modes are fairly immune to many of the technical issues that challenge off-resonant 2D Raman spectroscopies (e.g., third-order cascades) and photon-echo experiments in the deep UV (e.g., coherence spikes). The development of higher-order nonlinear spectroscopies operational in the deep UV is motivated by studies of biological systems and elementary organic photochemistries.

  18. Multiwavelength Raman spectroscopy analysis of a large sampling of disordered carbons extracted from the Tore Supra tokamak

    E-Print Network [OSTI]

    Pardanaud, Cedric; Roubin, P

    2014-01-01

    Disordered carbon often exhibit a complex Raman spectrum, with four to six components. Here, a large variety of disordered carbons, forming a collection of samples with a great variety of structures, are analysed using multi-wavelength Raman microscopy (325.0, 514.5, 785.0 nm). They allow us to extend Raman behaviour known for nano-crystalline graphite to amorphous carbons, (dependence with the excitation wavelength) and other known for amorphous carbons to nano-crystalline graphite, (differentiation of the smallest cluster size probed using different excitation wavelengths). Experimental spectra were compared to simulated spectra, built using known laws, to evidence a new source of broadening.

  19. Raman-scattering-assistant broadband noise-like pulse generation in all-normal-dispersion fiber lasers

    E-Print Network [OSTI]

    Li, Daojing; Li, Lei; Chen, Hao; Tang, Dingyuan; Zhao, Luming

    2015-01-01

    We report on the observation of both stable dissipative solitons and noise-like pulses with the presence of strong Raman scattering in a relatively short all-normal-dispersion Yb-doped fiber laser. We show that Raman scattering can be filtered out by intracavity filter. Furthermore, by appropriate intracavity polarization control, the Raman effect can be utilized to generate broadband noise-like pulses (NLPs) with bandwidth up to 61.4 nm. To the best of our knowledge, this is the broadest NLP achieved in all-normal-dispersion fiber lasers

  20. Analysis of mixing layer heights inferred from radiosonde, wind profiler, airborne lidar, airborne microwave temperature profiler, and in-situ aircraft data during the Texas 2000 air quality study in Houston, TX 

    E-Print Network [OSTI]

    Smith, Christina Lynn

    2005-08-29

    The mixing layer (ML) heights inferred from radiosondes, wind profilers, airborne lidar, airborne microwave temperature profiler (MTP), and in-situ aircraft data were compared during the Texas 2000 Air Quality Study in the Houston area...

  1. Remote Raman - laser induced breakdown spectroscopy (LIBS) geochemical investigation under Venus atmospheric conditions

    SciTech Connect (OSTI)

    Clegg, Sanuel M; Barefield, James E; Humphries, Seth D; Wiens, Roger C; Vaniman, D. T.; Sharma, S. K.; Misra, A. K.; Dyar, M. D.; Smrekar, S. E.

    2010-12-13

    The extreme Venus surface temperatures ({approx}740 K) and atmospheric pressures ({approx}93 atm) create a challenging environment for surface missions. Scientific investigations capable of Venus geochemical observations must be completed within hours of landing before the lander will be overcome by the harsh atmosphere. A combined remote Raman - LIBS (Laser Induced Breakdown Spectroscopy) instrument is capable of accomplishing the geochemical science goals without the risks associated with collecting samples and bringing them into the lander. Wiens et al. and Sharma et al. demonstrated that both analytical techniques can be integrated into a single instrument capable of planetary missions. The focus of this paper is to explore the capability to probe geologic samples with Raman - LIBS and demonstrate quantitative analysis under Venus surface conditions. Raman and LIBS are highly complementary analytical techniques capable of detecting both the mineralogical and geochemical composition of Venus surface materials. These techniques have the potential to profoundly increase our knowledge of the Venus surface composition, which is currently limited to geochemical data from Soviet Venera and VEGA landers that collectively suggest a surface composition that is primarily tholeiitic basaltic with some potentially more evolved compositions and, in some locations, K-rich trachyandesite. These landers were not equipped to probe the surface mineralogy as can be accomplished with Raman spectroscopy. Based on the observed compositional differences and recognizing the imprecise nature of the existing data, 15 samples were chosen to constitute a Venus-analog suite for this study, including five basalts, two each of andesites, dacites, and sulfates, and single samples of a foidite, trachyandesite, rhyolite, and basaltic trachyandesite under Venus conditions. LIBS data reduction involved generating a partial least squares (PLS) model with a subset of the rock powder standards to quantitatively determine the major elemental abundance of the remaining samples. PLS analysis suggests that the major element compositions can be determined with root mean square errors ca. 5% (absolute) for SiO{sub 2}, Al{sub 2}O{sub 3}, Fe{sub 2}O{sub 3}(total), MgO, and CaO, and ca. 2% or less for TiO{sub 2}, Cr{sub 2}O{sub 3}, MnO, K{sub 2}O, and Na{sub 2}O. Finally, the Raman experiments have been conducted under supercritical CO{sub 2} involving single-mineral and mixed-mineral samples containing talc, olivine, pyroxenes, feldspars, anhydrite, barite, and siderite. The Raman data have shown that the individual minerals can easily be identified individually or in mixtures.

  2. Assessment of liver steatosis and fibrosis in rats using integrated coherent anti-Stokes Raman scattering and multiphoton imaging technique

    E-Print Network [OSTI]

    Lin, Jian

    We report the implementation of a unique integrated coherent anti-Stokes Raman scattering (CARS), second-harmonic generation (SHG), and two-photon excitation fluorescence (TPEF) microscopy imaging technique developed for ...

  3. Theory of femtosecond coherent anti-Stokes Raman backscattering enhanced by quantum coherence for standoff detection of bacterial spores 

    E-Print Network [OSTI]

    Ooi, C. H. Raymond; Beadie, G.; Kattawar, George W.; Reintjes, J. F.; Rostovtsev, Y.; Zubairy, M. Suhail; Scully, Marlan O.

    2005-01-01

    Backscattered signal of coherent anti-Stokes Raman spectroscopy can be an extremely useful tool for remote identification of airborne particles, provided the signal is sufficiently large. We formulate a semiclassical theory of nonlinear scattering...

  4. Stimulated Raman scattering of laser in a plasma in the presence of a co-propagating electron beam

    SciTech Connect (OSTI)

    Parashar, J. [Department of Physics, Samrat Ashok Technological Institute, Vidisha, Madhya Pradesh 464001 (India)] [Department of Physics, Samrat Ashok Technological Institute, Vidisha, Madhya Pradesh 464001 (India)

    2013-12-15

    A relativistic electron beam co-propagating with a high power laser in plasma is shown to add to the growth of the stimulated Raman back scattering of the laser. The growth rate is sensitive to phase matching of electron beam with the plasma wave. In the case of phase mismatch, the growth rate drops by an order. The energy spread of the electron beam significantly reduces the effectiveness of the beam on the stimulated Raman process.

  5. Rapid and Nondestructive Identification of Polytypism and Stacking Sequences in Few-Layer Molybdenum Diselenide by Raman Spectroscopy

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Lu, Xin; Utama, M. Iqbal Bakti; Lin, Junhao; Luo, Xin; Zhao, Yanyuan; Zhang, Jun; Pantelides, Sokrates T.; Zhou, Wu; Quek, Su Ying; Xiong, Qihua

    2015-07-02

    Various combinations of interlayer shear modes emerge in few-layer molybdenum diselenide grown by chemical vapor deposition depending on the stacking configuration of the sample. Raman measurements may also reveal polytypism and stacking faults, as supported by first principles calculations and high-resolution transmission electron microscopy. Thus, Raman spectroscopy is an important tool in probing stacking-dependent properties in few-layer 2D materials.

  6. Multilayer graphene stacks grown by different methods-thickness measurements by X-ray diffraction, Raman spectroscopy and optical transmission

    SciTech Connect (OSTI)

    Tokarczyk, M., E-mail: mateusz.tokarczyk@fuw.edu.pl; Kowalski, G.; K?pa, H.; Grodecki, K.; Drabi?ska, A. [University of Warsaw, Institute of Experimental Physics, Faculty of Physics (Poland); Strupi?ski, W. [Institute of Electronic Materials Technology (Poland)

    2013-12-15

    X-ray diffraction, Raman spectroscopy and Optical absorption estimates of the thickness of graphene multi layer stacks (number of graphene layers) are presented for three different growth techniques. The objective of this work was focused on comparison and reconciliation of the two already widely used methods for thickness estimates (Raman and Absorption) with the calibration of the X-ray method as far as Scherer constant K is concerned and X-ray based Wagner-Aqua extrapolation method.

  7. Raman spectroscopy of perovskite and post-perovskite phases of MgGeO3 to 123 GPa

    E-Print Network [OSTI]

    Duffy, Thomas S.

    Raman spectroscopy of perovskite and post-perovskite phases of MgGeO3 to 123 GPa Sang-Heon Shim a 19 May 2007 Editor: G.D. Price Available online 26 May 2007 Abstract Raman spectra of the perovskite (Pv) and post-perovskite (PPv) phases of MgGeO3 were measured in the laser-heated diamond cell up

  8. Time interval and lattice vibration in Raman effect, photoelectric effect and plane mirror reflection

    E-Print Network [OSTI]

    M. Kumar; S. Sahoo

    2012-07-02

    Time interval between the incident and scattered photon in Raman effect and absorption of photon and emission of electron in photoelectric effect has not been determined till now. This is because there is no such high level instrument discovered till now to detect time interval to such a small level. But this can be calculated theoretically by applying a basic principle of physics like impulse is equal to the change in momentum. Considering the collision between electron and photon as perfect inelastic collision in photoelectric effect, elastic and inelastic collision in Raman effect and elastic collision in plane mirror reflection and the interaction between electron and photon as strong gravitational interaction we calculate the required time interval. During these phenomena there is lattice vibration which can be quantized as phonon particles.

  9. Transient effects and pump depletion in stimulated Raman scattering. [Para-hydrogen

    SciTech Connect (OSTI)

    Carlsten, J.L.; Wenzel, R.G.; Druehl, K.

    1983-01-01

    Stimulated rotational Raman scattering in a 300-K multipass cell filled with para-H/sub 2/ with a single-mode CO/sub 2/-pumped laser is studied using a frequency-narrowed optical parametric oscillator (OPO) as a probe laser at the Stokes frequency for the S/sub 0/(O) transition. Amplification and pump depletion are examined as a function of incident pump energy. The pump depletion shows clear evidence of transient behavior. A theoretical treatment of transient stimulated Raman scattering, including effects of both pump depletion and medium saturation is presented. In a first approximation, diffraction effects are neglected, and only plane-wave interactions are considered. The theoretical results are compared to the experimental pulse shapes.

  10. Stimulated Raman scattering of laser dye mixtures dissolved in multiple scattering media

    SciTech Connect (OSTI)

    Yashchuk, V P; Komyshan, A O; Tikhonov, E A; Olkhovyk, L A

    2014-10-31

    Stimulated Raman scattering (SRS) of a mixture of rhodamine 6G and pyrromethene 605 laser dyes in vesicular films is studied. It is shown that a peculiar interaction of dyes occurs under conditions of multiple scattering of light from vesicles. This interaction manifests itself as SRS excitation of one of the dyes by random lasing of the other dye, provided that the random lasing spectrum overlaps the Stokes lines of the first dye. In addition, there is energy transfer between molecules of these dyes if their luminescence and absorption spectra overlap. The results obtained confirm that the mechanism of SRS from laser dyes in multiple scattering media is similar to that in coherent-active Raman spectroscopy. These results extend the possibility of determining the vibrational spectrum of dye molecules from their secondary radiation in these media. (nonlinear optical phenomena)

  11. Single-Beam Coherent Raman Spectroscopy and Microscopy via Spectral Notch Shaping

    E-Print Network [OSTI]

    Katz, Ori; Grinvald, Eran; Silberberg, Yaron

    2010-01-01

    Raman spectroscopy is one of the key techniques in the study of vibrational modes and molecular structures. In Coherent Anti-Stokes Raman Scattering (CARS) spectroscopy, a molecular vibrational spectrum is resolved via the third-order nonlinear interaction of pump, Stokes and probe photons, typically using a complex experimental setup with multiple beams and laser sources. Although CARS has become a widespread technique for label-free chemical imaging and detection of contaminants, its multi-source, multi-beam experimental implementation is challenging. In this work we present a simple and easily implementable scheme for performing single-beam CARS spectroscopy and microscopy using a single femtosecond pulse, shaped by a tunable narrowband notch filter. As a substitute for multiple sources, the single broadband pulse simultaneously provides the pump, Stokes and probe photons, exciting a broad band of vibrational levels. High spectroscopic resolution is obtained by utilizing a tunable spectral notch, shaped wi...

  12. Raman scattering enhancement in photon-plasmon resonance mediated metal-dielectric microcavity

    SciTech Connect (OSTI)

    Guddala, Sriram; Narayana Rao, D., E-mail: dnr.laserlab@gmail.com, E-mail: dnrsp@uohyd.ernet.in [School of Physics, University of Hyderabad, Hyderabad 500 046 (India); Dwivedi, Vindesh K.; Vijaya Prakash, G. [Nanophotonics Laboratory, Department of Physics, IIT Delhi, New Delhi 110 016 (India)

    2013-12-14

    Here, we report the photon-plasmon interaction scheme and enhanced field strengths resulted into the amplification of phonon in a novel microcavity. A metal-dielectric microcavity, with unified cavity photonic mode and localized surface plasmon resonances, is visualized by impregnating the gold nanoparticles into the deep see-through nano-sized pores of porous silicon microcavity. The intense optical field strengths resulting from the photon-plasmon interactions are probed by both resonant and non-resonant Raman scattering experiments. Due to photon-plasmon-phonon interaction mechanism, several orders of enhancement in the intensity of scattered Raman Stokes photon (at 500?cm{sup ?1}) are observed. Our metal nanoparticle-microcavity hybrid system shows the potential to improve the sensing figure of merit as well as the applications of plasmonics for optoelectronics, photovoltaics, and related technologies.

  13. Studies of ground-state dynamics in isolated species by ionization-detected stimulated Raman techniques

    SciTech Connect (OSTI)

    Felker, P.M.

    1993-12-01

    First, the author aims to develop methods of nonlinear Raman spectroscopy for application in studies of sparse samples. Second, the author wishes to apply such methods to structural and dynamical studies of species (molecules, complexes, and clusters) in supersonic molecular beams. In the past year, the author has made progress in several areas. The first pertains to the application of mass-selective ionization-detected stimulated Raman spectroscopies (IDSRS) to the size-specific vibrational spectroscopy of solute-solvent{sub n} clusters. The second involves the application of IDSRS methods to studies of jet-cooled benzene clusters. The third pertains to the use of IDSRS methods in the study of intermolecular vibrational transitions in van der Waals complexes.

  14. Application of Raman spectroscopy to identification and sorting of post-consumer plastics for recycling

    DOE Patents [OSTI]

    Sommer, Edward J. (Nashville, TN); Rich, John T. (Lebanon, TN)

    2001-01-01

    A high accuracy rapid system for sorting a plurality of waste products by polymer type. The invention involves the application of Raman spectroscopy and complex identification techniques to identify and sort post-consumer plastics for recycling. The invention reads information unique to the molecular structure of the materials to be sorted to identify their chemical compositions and uses rapid high volume sorting techniques to sort them into product streams at commercially viable throughput rates. The system employs a laser diode (20) for irradiating the material sample (10), a spectrograph (50) is used to determine the Raman spectrum of the material sample (10) and a microprocessor based controller (70) is employed to identify the polymer type of the material sample (10).

  15. Single-shot hyperspectral coherent Raman planar imaging in the range 0–4200 cm?¹

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Bohlin, Alexis; Kliewer, Christopher J.

    2014-10-20

    We propose a technique for ultrabroadband planar coherent Raman spectroscopy that enables wideband chemically selective mapping of molecular partition functions in the gas-phase within a single-laser-shot. A spectral region spanning 0–4200 cm?¹ is excited simultaneously, in principle allowing for coherent planar imaging of most all fundamental Raman-active modes. This unique instantaneous and spatially correlated assessment enables multiplexed studies of transient dynamical systems in a two-dimensional (2D) field. Here, we demonstrate single-laser-shot high temperature diagnostics of H?, with spatially resolved 2D measurement of transitions of both the pure-rotational H? S-branch and the vibrational H? Q-branch, analyzing the temperature contour of amore »reacting fuel-species as it evolves at a flame-front.« less

  16. Raman Scattering of Water and Photoluminescence of Pollutants Arising from Solid-Water Interaction

    E-Print Network [OSTI]

    Vallée, P; Ghomi, M; Jouanne, M; Vall\\'{e}e, Philippe; Lafait, Jacques; Ghomi, Mahmoud; Jouanne, Michel

    2003-01-01

    Systematic Raman experiments performed on water and water-ethanol samples, stored in different containers (fused silica, polypropylene, soda-lime glass type III) for several hours, have shown that the luminescence contribution to the Raman signal fluctuations is directly related to the container composition. Intensity fluctuations as large as 98%, have been observed in the spectral regions corresponding to the both water intramolecular and intermolecular vibrations, despite the fact that the wavenumbers of the modes remained unchanged. We undoubtedly attribute these fluctuations to a luminescence phenomenon on the basis of : i) the absence of such effect in the anti-Stokes domain, ii) its dependence on the excitation laser wavelength, iii) other relevant photoluminescence experiments. This luminescence is attributed to pollutants at ultra-low concentration coming from the different containers.

  17. Shifting of infrared radiation using rotational raman resonances in diatomic molecular gases

    DOE Patents [OSTI]

    Kurnit, Norman A. (Santa Fe, NM)

    1980-01-01

    A device for shifting the frequency of infrared radiation from a CO.sub.2 laser by stimulated Raman scattering in either H.sub.2 or D.sub.2. The device of the preferred embodiment comprises an H.sub.2 Raman laser having dichroic mirrors which are reflective for 16 .mu.m radiation and transmittive for 10 .mu.m, disposed at opposite ends of an interaction cell. The interaction cell contains a diatomic molecular gas, e.g., H.sub.2, D.sub.2, T.sub.2, HD, HT, DT and a capillary waveguide disposed within the cell. A liquid nitrogen jacket is provided around the capillary waveguide for the purpose of cooling. In another embodiment the input CO.sub.2 radiation is circularly polarized using a Fresnel rhomb .lambda./4 plate and applied to an interaction cell of much longer length for single pass operation.

  18. Surface-enhanced Raman medical probes and system for disease diagnosis and drug testing

    DOE Patents [OSTI]

    Vo-Dinh, T.

    1999-01-26

    A probe for a surface-enhanced Raman scattering spectrometer includes a member of optically transmissive material for receiving the excitation radiation from a laser and for carrying the radiation emitted from a specimen to a detector. An end of the member for placing against the specimen has a coating that produces surface enhancement of the specimen during Raman scattering spectroscopic analysis. Specifically the coating is formed by a first layer of microparticles on the member and a metal layer over the first layer. The first layer may form a microstructure surface over which a metal layer is applied. Alternatively the coating may be a material containing microparticles of a metal. An optional layer of a material may be applied to the metal layer to concentrate onto the probe compounds of analytical interest onto the probe. 39 figs.

  19. Vibrational Imaging with High Sensitivity via Epidetected Coherent Anti-Stokes Raman Scattering Microscopy

    SciTech Connect (OSTI)

    Volkmer, Andreas; Cheng, Ji-Xin; Sunney Xie, X.

    2001-07-09

    We demonstrate theoretically and experimentally a novel epidetection scheme for coherent anti-Stokes Raman scattering (CARS) microscopy that significantly improves the detection sensitivity. Calculations show that epidetected CARS (E-CARS) signals are present for scatterers smaller than the wavelength of light, whereas the large background signals from the surrounding bulk solvent are suppressed by destructive interference. E-CARS microscopy is capable of revealing small intracellular features that are otherwise buried by the strong water CARS signal.

  20. Realization of the Dicke model using cavity-assisted Raman transitions

    E-Print Network [OSTI]

    Markus P. Baden; Kyle J. Arnold; Arne L. Grimsmo; Scott Parkins; Murray D. Barrett

    2014-07-11

    We realize an open version of the Dicke model by coupling two hyperfine ground states using two cavity-assisted Raman transitions. The interaction due to only one of the couplings is described by the Tavis-Cummings model and we observe a normal mode splitting in the transmission around the dispersively shifted cavity. With both couplings present the dynamics are described by the Dicke model and we measure the onset of superradiant scattering into the cavity above a critical coupling strength.

  1. Water O?H Stretching Raman Signature for Strong Acid Monitoring via Multivariate Analysis

    SciTech Connect (OSTI)

    Casella, Amanda J.; Levitskaia, Tatiana G.; Peterson, James M.; Bryan, Samuel A.

    2013-04-16

    Spectroscopic techniques have been applied extensively for quantification and analysis of solution compositions. In addition to static measurements, these techniques have been implemented in flow systems providing real-time solution information. A distinct need exists for information regarding acid concentration as it affects extraction efficiency and selectivity of many separation processes. Despite of the seeming simplicity of the problem, no practical solution has been offered yet particularly for the large-scale schemes involving toxic streams such as highly radioactive nuclear wastes. Classic potentiometric technique is not amiable for on-line measurements in nuclear fuel reprocessing due to requirements of frequent calibration/maintenance and poor long-term stability in the aggressive chemical and radiation environments. In this work, the potential of using Raman spectroscopic measurements for on-line monitoring of strong acid concentration in the solutions relevant to the dissolved used fuel was investigated. The Raman water signature was monitored and recorded for nitric and hydrochloric acid solution systems of systematically varied chemical composition, ionic strength, and temperature. The generated Raman spectroscopic database was used to develop predictive chemometric models for the quantification of the acid concentration (H+), neodymium concentration (Nd3+), nitrate concentration (NO3-), density, and ionic strength. This approach was validated using a flow solvent extraction system.

  2. Wide-angle imaging LIDAR (WAIL): a ground-based instrument for monitoring the thickness and density of optically thick clouds.

    SciTech Connect (OSTI)

    Love, Steven P.; Davis, A. B. (Anthony B.); Rohde, C. A. (Charles A.); Ho, Cheng,

    2001-01-01

    Traditional lidar provides little information on dense clouds beyond the range to their base (ceilometry), due to their extreme opacity. At most optical wavelengths, however, laser photons are not absorbed but merely scattered out of the beam, and thus eventually escape the cloud via multiple scattering, producing distinctive extended space- and time-dependent patterns which are, in essence, the cloud's radiative Green functions. These Green functions, essentially 'movies' of the time evolution of the spatial distribution of escaping light, are the primary data products of a new type of lidar: Wide Angle Imaging Lidar (WAIL). WAIL data can be used to infer both optical depth and physical thickness of clouds, and hence the cloud liquid water content. The instrumental challenge is to accommodate a radiance field varying over many orders of magnitude and changing over widely varying time-scales. Our implementation uses a high-speed microchannel plate/crossed delay line imaging detector system with a 60-degree full-angle field of view, and a 532 nm doubled Nd:YAG laser. Nighttime field experiments testing various solutions to this problem show excellent agreement with diffusion theory, and retrievals yield plausible values for the optical and geometrical parameters of the observed cloud decks.

  3. Coherent Anti-Stokes Raman Scattering Spectroscopy of Single Molecules in Solution

    SciTech Connect (OSTI)

    Sunney Xie, Wei Min, Chris Freudiger, Sijia Lu

    2012-01-18

    During this funding period, we have developed two breakthrough techniques. The first is stimulated Raman scattering microscopy, providing label-free chemical contrast for chemical and biomedical imaging based on vibrational spectroscopy. Spontaneous Raman microscopy provides specific vibrational signatures of chemical bonds, but is often hindered by low sensitivity. We developed a three-dimensional multiphoton vibrational imaging technique based on stimulated Raman scattering (SRS). The sensitivity of SRS imaging is significantly greater than that of spontaneous Raman microscopy, which is achieved by implementing high-frequency (megahertz) phase-sensitive detection. SRS microscopy has a major advantage over previous coherent Raman techniques in that it offers background-free and readily interpretable chemical contrast. We demonstrated a variety of biomedical applications, such as differentiating distributions of omega-3 fatty acids and saturated lipids in living cells, imaging of brain and skin tissues based on intrinsic lipid contrast, and monitoring drug delivery through the epidermis. This technology offers exciting prospect for medical imaging. The second technology we developed is stimulated emission microscopy. Many chromophores, such as haemoglobin and cytochromes, absorb but have undetectable fluorescence because the spontaneous emission is dominated by their fast non-radiative decay. Yet the detection of their absorption is difficult under a microscope. We use stimulated emission, which competes effectively with the nonradiative decay, to make the chromophores detectable, as a new contrast mechanism for optical microscopy. We demonstrate a variety of applications of stimulated emission microscopy, such as visualizing chromoproteins, non-fluorescent variants of the green fluorescent protein, monitoring lacZ gene expression with a chromogenic reporter, mapping transdermal drug distribu- tions without histological sectioning, and label-free microvascular imaging based on endogenous contrast of haemoglobin. For all these applications, sensitivity is orders of magnitude higher than for spontaneous emission or absorption contrast, permitting nonfluorescent reporters for molecular imaging. Although we did not accomplish the original goal of detecting single-molecule by CARS, our quest for high sensitivity of nonlinear optical microscopy paid off in providing the two brand new enabling technologies. Both techniques were greatly benefited from the use of high frequency modulation for microscopy, which led to orders of magnitude increase in sensitivity. Extensive efforts have been made on optics and electronics to accomplish these breakthroughs.

  4. Ultraviolet resonance Raman spectroscopy of the integral membrane protein OmpA : elucidating structure and tryptophan microenvironment of folded and unfolded states

    E-Print Network [OSTI]

    Neary, Tiffany Jonean

    2008-01-01

    Elastic Coupling of Integral Membrane Protein Stability toThermodynamic Stability of Integral Membrane Proteins,” J.Raman Spectroscopy of the Integral Membrane Protein OmpA:

  5. Note: Deep ultraviolet Raman spectrograph with the laser excitation line down to 177.3 nm and its application

    SciTech Connect (OSTI)

    Jin, Shaoqing; University of the Chinese Academy of Sciences, Beijing 100049 ; Fan, Fengtao; Guo, Meiling; Zhang, Ying; Feng, Zhaochi E-mail: canli@dicp.ac.cn; Li, Can E-mail: canli@dicp.ac.cn

    2014-04-15

    Deep UV Raman spectrograph with the laser excitation line down to 177.3 nm was developed in this laboratory. An ellipsoidal mirror and a dispersed-subtractive triple monochromator were used to collect and disperse Raman light, respectively. The triple monochromator was arranged in a triangular configuration with only six mirrors used. 177.3 nm laser excited Raman spectrum with cut-off wavenumber down to 200 cm{sup ?1} and spectral resolution of 8.0 cm{sup ?1} can be obtained under the condition of high purity N{sub 2} purging. With the C–C ? bond in Teflon selectively excited by the 177.3 nm laser, resonance Raman spectrum of Teflon with good quality was recorded on the home-built instrument and the ?-?{sup *} transition of C–C bond was studied. The result demonstrates that deep UV Raman spectrograph is powerful for studying the systems with electronic transition located in the deep UV region.

  6. Bandwidth optimization of femtosecond pure-rotational coherent anti-Stokes Raman scattering by pump/Stokes spectral focusing.

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Kearney, Sean Patrick

    2014-07-01

    A simple spectral focusing scheme for bandwidth optimization of gas-phase rotational coherent anti-Stokes Raman scattering (CARS) spectra is presented. The method is useful when femtosecond pump/Stokes preparation of the Raman coherence is utilized. The approach is of practical utility when working with laser pulses that are not strictly transform limited, or when windows or other sources of pulse chirp may be present in the experiment. A delay between the femtosecond preparation pulses is introduced to shift the maximum Raman preparation away from zero frequency and toward the Stokes or anti-Stokes side of the spectrum with no loss in total preparationmore »bandwidth. Shifts of 100 cm-1 or more are attainable and allow for enhanced detection of high-energy (150-300 cm-1) rotational Raman transitions at near transform-limited optimum sensitivity. A simple theoretical treatment for the case of identical pump and Stokes pulses with linear frequency chirp is presented. The approach is then demonstrated experimentally for typical levels of transform-limited laser performance obtained our laboratory with nonresonant CARS in argon and Raman-resonant spectra from a lean H2/air flat flame.« less

  7. Study of structure of the TiO{sub 2}–MoO{sub 3} bilayer films by Raman spectroscopy

    SciTech Connect (OSTI)

    Santos, Elias de Barros; Sigoli, Fernando Aparecido; Mazali, Italo Odone

    2014-12-15

    Highlights: • TiO{sub 2}–MoO{sub 3} bilayer thin films were easily prepared by dip-coating technique. • Ti and Mo metallo-organic compounds were used as source of its respective oxide. • TiO{sub 2} in anatase phase and orthorhombic phase of ?-MoO{sub 3} were identified. • The bilayer structure was investigated by Raman spectroscopy. - Abstract: In this work, TiO{sub 2}–MoO{sub 3} films were easily prepared by dip-coating technique and metallo-organic decomposition process (MOD). Raman analyses indicate the formation of TiO{sub 2} in anatase phase and orthorhombic phase of ?-MoO{sub 3}. It was observed that the Raman bands intensities attributed to TiO{sub 2} and MoO{sub 3} oxides were dependent on the number of decomposition–deposition cycles (DDC). The different number of DDC generates films with different thicknesses and the Raman signal was sensitive to this variation. Raman analyses provided qualitative information about the bilayer structure of the bi-component TiO{sub 2}–MoO{sub 3} films, which was confirmed by scanning electron microscopy. In this direction, the dip-coating technique and MOD process can be an efficient strategy to facile preparation of many samples to be used in applications.

  8. Joint retrievals of cloud and drizzle in marine boundary layer clouds using ground-based radar, lidar and zenith radiances

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Fielding, M. D.; Chiu, J. C.; Hogan, R. J.; Feingold, G.; Eloranta, E.; O'Connor, E. J.; Cadeddu, M. P.

    2015-07-02

    Active remote sensing of marine boundary-layer clouds is challenging as drizzle drops often dominate the observed radar reflectivity. We present a new method to simultaneously retrieve cloud and drizzle vertical profiles in drizzling boundary-layer clouds using surface-based observations of radar reflectivity, lidar attenuated backscatter, and zenith radiances under conditions when precipitation does not reach the surface. Specifically, the vertical structure of droplet size and water content of both cloud and drizzle is characterised throughout the cloud. An ensemble optimal estimation approach provides full error statistics given the uncertainty in the observations. To evaluate the new method, we first perform retrievalsmore »using synthetic measurements from large-eddy simulation snapshots of cumulus under stratocumulus, where cloud water path is retrieved with an error of 31 g m-2. The method also performs well in non-drizzling clouds where no assumption of the cloud profile is required. We then apply the method to observations of marine stratocumulus obtained during the Atmospheric Radiation Measurement MAGIC deployment in the Northeast Pacific. Here, retrieved cloud water path agrees well with independent three-channel microwave radiometer retrievals, with a root mean square difference of 10–20 g m-2.« less

  9. Joint retrievals of cloud and drizzle in marine boundary layer clouds using ground-based radar, lidar and zenith radiances

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Fielding, M. D.; Chiu, J. C.; Hogan, R. J.; Feingold, G.; Eloranta, E.; O'Connor, E. J.; Cadeddu, M. P.

    2015-02-16

    Active remote sensing of marine boundary-layer clouds is challenging as drizzle drops often dominate the observed radar reflectivity. We present a new method to simultaneously retrieve cloud and drizzle vertical profiles in drizzling boundary-layer cloud using surface-based observations of radar reflectivity, lidar attenuated backscatter, and zenith radiances. Specifically, the vertical structure of droplet size and water content of both cloud and drizzle is characterised throughout the cloud. An ensemble optimal estimation approach provides full error statistics given the uncertainty in the observations. To evaluate the new method, we first perform retrievals using synthetic measurements from large-eddy simulation snapshots of cumulusmore »under stratocumulus, where cloud water path is retrieved with an error of 31 g m?2. The method also performs well in non-drizzling clouds where no assumption of the cloud profile is required. We then apply the method to observations of marine stratocumulus obtained during the Atmospheric Radiation Measurement MAGIC deployment in the northeast Pacific. Here, retrieved cloud water path agrees well with independent 3-channel microwave radiometer retrievals, with a root mean square difference of 10–20 g m?2.« less

  10. Raman Scattering Sensor for On-Line Monitoring of Amines and Acid Gases

    SciTech Connect (OSTI)

    Uibel, Rory; Smith, Lee

    2010-05-20

    Sulfur and CO2 removal from hydrocarbon streams and power plant effluents are a major problem. The sulfur is normally in the form of H2S. These two acid gases are scrubbed using aqueous amine solutions that are difficult to control with conventional technology. Process Instruments Inc. developed Raman scattering technology for on-line, real-time monitoring of amine streams to improve their efficiency in scrubbing H2S and CO2 from hydrocarbon streams and power plant effluents. Improved control of amine and acid gas concentrations will allow refineries, natural gas processes and power plants to more efficiently scrub Sulfur and CO2, saving energy, time and financial resources.

  11. Methods and systems for Raman and optical cross-interrogation in flow-through silicon membranes

    DOE Patents [OSTI]

    Bond, Tiziana C.; Letant, Sonia E.

    2014-09-09

    Cross-interrogating photonic detection systems and methods are shown. A flow through photonic crystal membrane with a surface enhanced Raman scattering (SERS) substrate is provided with pores which are distributed along multiple regions. The pores of one region have walls to which a first type of target specific anchor can be attached, while pores of another region have walls to which a second type of target specific anchor can be attached. An optical arrangement out-of-plane to the SERS substrate is also provided for enhanced sensitivity and identification of target organisms.

  12. Numerical investigation of mid-infrared Raman soliton source generation in endless single mode fluoride fibers

    SciTech Connect (OSTI)

    Liu, Lai; Qin, Guan-Shi, E-mail: qings@jlu.edu.cn; Tian, Qi-jun; Zhao, Dan; Qin, Wei-Ping, E-mail: wpqin@jlu.edu.cn [State Key Laboratory on Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University, Changchun 130012 (China)

    2014-04-28

    We numerically investigate Raman soliton generation in a fluoride photonic crystal fiber (PCF) pumped by 1.93 ?m femtosecond fiber lasers in order to get widely tunable laser source in the mid-infrared region. The simulated results show that a continuously tunable range (1.93???3.95??m) over 2000?nm is achieved in 1-m-long fluoride PCF pumped by a 1.93??m femtosecond fiber laser with a pulse width of 200 fs. The power conversion efficiency is also calculated and the maximum efficiency can be up to 84.27%.

  13. Single-pulse phase-control interferometric coherent anti-Stokes Raman scattering spectroscopy

    SciTech Connect (OSTI)

    Lim, S.-H.; Caster, Allison G.; Leone, Stephen R.

    2005-10-15

    In coherent anti-Stokes Raman scattering (CARS) spectroscopy experiments, usually the amplitude of the signal is measured and the phase information is lost. With a polarization- and phase-controlled pulse shaping technique, the relative phase between the resonant and nonresonant CARS signals is controlled, and spectral interferometry is performed without an interferometer. Both the real and imaginary parts of the background-free resonant CARS spectrum are measured via spectral interferometry between the resonant and nonresonant signals from the same sample. The resonant signal is amplified significantly by homodyne mixing with the nonresonant signal as a local oscillator, greatly improving the detection limit.

  14. Nonlinear Raman Techniques in Femtosecond Time Resolved Spectroscopy for the Analysis and Control of Molecular Dynamics

    SciTech Connect (OSTI)

    Materny, Arnulf; Konradi, Jakow; Namboodiri, Vinu; Namboodiri, Mahesh; Scaria, Abraham

    2008-11-14

    The use of four-wave mixing techniques in femtosecond time-resolved spectroscopy has considerable advantages. Due to the many degrees of freedom offered e.g. by coherent anti-Stokes Raman scattering (CARS), the dynamics even of complex systems can be analyzed in detail. Using pulse shaping techniques in combination with a self-learning loop approach, molecular mode excitation can be controlled very efficiently in a multi-photon excitation process. Results obtained from the optimal control of CARS on {beta}-carotene are discussed.

  15. Single pulse phase-control interferometric coherent anti-StokesRaman scattering spectroscopy (CARS)

    SciTech Connect (OSTI)

    Lim, Sang-Hyun; Caster, Allison G.; Leone, Stephen R.

    2005-09-28

    In coherent anti-Stokes Raman scattering spectroscopy (CARS) experiments, usually the amplitude of the signal is measured and the phase information is lost. With a polarization- and phase-controlled pulse shaping technique, the relative phase between the resonant and non-resonant CARS signals is controlled, and spectral interferometry is performed without an interferometer. Both the real and imaginary parts of the background-free resonant CARS spectrum are measured via spectral interferometry between the resonant and non-resonant signals from the same sample. The resonant signal is amplified significantly by homodyne mixing with the non-resonant signal as a local oscillator, greatly improving the detection limit.

  16. Manipulation of the Raman process via incoherent pump, tunable intensity, and phase control 

    E-Print Network [OSTI]

    Wang, Li-Gang; Qamar, Sajid; Zhu, Shi-Yao; Zubairy, M. Suhail

    2008-01-01

    of the Raman process via incoherent pump, tunable intensity, and phase control Li-Gang Wang,1,2,3 Sajid Qamar,1 Shi-Yao Zhu,1,2,3 and M. Suhail Zubairy1,4,5 1Centre for Quantum Physics, COMSATS Institute of Information Technology, Islamabad, Pakistan 2...Department of Physics, Zhejiang University, Hangzhou 310027, China 3Department of Physics, Hong Kong Baptist University, Hong Kong, China 4Institute for Quantum Studies and Department of Physics, Texas A&M University, College Station, Texas 77845, USA 5...

  17. Optimally shaped narrowband pulses for femtosecond stimulated Raman spectroscopy in the range 330-750 nm

    E-Print Network [OSTI]

    Pontecorvo, E.; Ferrante, C.; Elles, Christopher G.

    2013-03-25

    . Capobianco, C. Manzoni, F. Baronio, G. F. Nalesso, C. De Angelis, R. Ramponi, and G. Cerullo, “Synthesis of picosecond pulses by spectral compression and shaping of #181737 - $15.00 USD Received 13 Dec 2012; revised 18 Feb 2013; accepted 19 Feb 2013... demonstrated a convenient and tunable source of narrow bandwidth Raman pump pulses extending from the visible to the UV. The technique is based on spectral compression (SC) of the output of a fs OPA via second harmonic generation (SHG) in a long BBO crystal...

  18. Combined raman and IR fiber-based sensor for gas detection

    DOE Patents [OSTI]

    Carter, Jerry C; Chan, James W; Trebes, James E; Angel, Stanley M; Mizaikoff, Boris

    2014-06-24

    A double-pass fiber-optic based spectroscopic gas sensor delivers Raman excitation light and infrared light to a hollow structure, such as a hollow fiber waveguide, that contains a gas sample of interest. A retro-reflector is placed at the end of this hollow structure to send the light back through the waveguide where the light is detected at the same end as the light source. This double pass retro reflector design increases the interaction path length of the light and the gas sample, and also reduces the form factor of the hollow structure.

  19. Functional Mn–Mg{sub k} cation complexes in GaN featured by Raman spectroscopy

    SciTech Connect (OSTI)

    Devillers, T. Bonanni, A.; Leite, D. M. G.; Department of Physics, São Paulo State University, Bauru–SP ; Dias da Silva, J. H.

    2013-11-18

    The evolution of the optical branch in the Raman spectra of (Ga,Mn)N:Mg epitaxial layers as a function of the Mn and Mg concentrations, reveals the interplay between the two dopants. We demonstrate that the various Mn-Mg-induced vibrational modes can be understood in the picture of functional Mn–Mg{sub k} complexes formed when substitutional Mn cations are bound to k substitutional Mg through nitrogen atoms, the number of ligands k being driven by the ratio between the Mg and the Mn concentrations.

  20. Two-dimensional stimulated resonance Raman spectroscopy of molecules with broadband x-ray pulses

    SciTech Connect (OSTI)

    Biggs, Jason D.; Zhang Yu; Healion, Daniel; Mukamel, Shaul [Department of Chemistry, University of California, Irvine, California 92697-2025 (United States)

    2012-05-07

    Expressions for the two-dimensional stimulated x-ray Raman spectroscopy (2D-SXRS) signal obtained using attosecond x-ray pulses are derived. The 1D- and 2D-SXRS signals are calculated for trans-N-methyl acetamide (NMA) with broad bandwidth (181 as, 14.2 eV FWHM) pulses tuned to the oxygen and nitrogen K-edges. Crosspeaks in 2D signals reveal electronic Franck-Condon overlaps between valence orbitals and relaxed orbitals in the presence of the core-hole.

  1. Rotational-Vibrational Raman Spectroscopy for Measurements of Thermochemistry in Non-isobaric Environments 

    E-Print Network [OSTI]

    Bayeh, Alexander C.

    2010-01-14

    upon Q-switch and flash lamps of the laser, respectively. Preliminary experiments con- ducted with the spectroscopy system were conducted in the non-isobaric flow field in the wake of an underexpanded jet nozzle with an approximate exit Mach number of 2...-VIBRATIONAL RAMAN SPECTROSCOPY FOR MEASUREMENTS OF THERMOCHEMISTRY IN NON-ISOBARIC ENVIRONMENTS A Thesis by ALEXANDER CHRISTIAN BAYEH Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements for the degree...

  2. An Epi-Detected Coherent Anti-Stokes Raman Scattering (E-CARS) Microscope with High Spectral Resolution and High Sensitivity

    E-Print Network [OSTI]

    Xie, Xiaoliang Sunney

    LETTERS An Epi-Detected Coherent Anti-Stokes Raman Scattering (E-CARS) Microscope with High-detected coherent anti-Stokes Raman scattering (E-CARS) microscope that uses two synchronized picosecond pulse (CARS) microscopy provides a unique approach to imaging chemical and biological samples by using

  3. Airborne Multiwavelength High-Spectral-Resolution Lidar (HSRL-2) Observations During TCAP 2012: Vertical Proles of Optical and Microphysical Properties of a Smoke/Urban Haze Plume Over the Northeastern Coast of the US

    SciTech Connect (OSTI)

    Muller, Detlef; Hostetler, Chris A.; Ferrare, R. A.; Burton, S. P.; Chemyakin, Eduard; Kolgotin, A.; Hair, John; Cook, A. L.; Harper, David; Rogers, R. R.; Hare, Rich; Cleckner, Craig; Obland, Michael; Tomlinson, Jason M.; Berg, Larry K.; Schmid, Beat

    2014-10-10

    We present rst measurements with the rst airborne multiwavelength High-Spectral Resolution Lidar (HSRL-2), developed by NASA Langley Research Center. The instrument was operated during the Department of Energy (DOE) Two-Column Aerosol Project (TCAP) in July 2012. We observed out ow of urban haze and fresh biomass burning smoke from the East Coast of the US out over the West Atlantic Ocean. Lidar ratios at 355 and 532 nm were ... sr indicating moderately absorbing aerosols. Extinctionrelated Angstrom exponents were 1.5{2 pointing at comparably small particles. Our novel automated, unsupervised data inversion algorithm retrieves particle e*ective radii of approximately 0.2 *m, which is in agreement with the large Angstrom exponents. We nd reasonable agreement to particle size parameters obtained from situ measurements carried out with the DOE G-1 aircraft that ew during the lidar observations.

  4. Journal of Optoelectronics and Advanced Materials Vol. 7, No. 1, February 2005, p. 473 -476 A RAMAN SPECTROSCOPIC STUDY OF DEFECTS IN Bi4Ge3O12 CRYSTALS

    E-Print Network [OSTI]

    Nabben, Reinhard

    A RAMAN SPECTROSCOPIC STUDY OF DEFECTS IN Bi4Ge3O12 CRYSTALS P. M. Rafailova,b* , T. I. Milenovb , M. N resolved polarized Raman measurements on a Czochralski grown Bi4Ge3O12 crystal, and observed significant) Keywords: Raman spectroscopy, Phonons, Lattice defects 1. Introduction Bi4Ge3O12 is a basic material

  5. Raman and XPS analyses of pristine and annealed N-doped double-walled carbon nanotubes

    E-Print Network [OSTI]

    Shi, Lei; Domanov, Oleg; Rohringer, Philip; Ayala, Paola; Pichler, Thomas

    2015-01-01

    N-doped single/multi-walled carbon nanotubes (CNTs) were studied for long time from synthesis to properties. However, the stability of N in the CNT lattice still needs further developments. In this work, to obtain more stable N-doped CNTs, concentric double-walled (DW) CNTs with more N were synthesized using benzylamine as C and N source. In order to test the stability of N-doped DWCNTs, high-temperature annealing in vacuum was performed. By XPS and Raman spectroscopic measurements, we found that the N-doped DWCNTs are still stable under 1500 $\\,^{\\circ}\\mathrm{C}$: the graphitic N does not change at all, the molecular N is partly removed, and the pyridinic N ratio greatly increases by more than two times. The reason could be that the N atoms from the surrounded N-contained materials combine into the CNT lattice during the annealing. Compared with the undoped DWCNTs, no Raman frequency shift was observed for the RBM, the G-band, and the G'-band of the N-doped DWCNTs.

  6. Solvent effects on the resonance Raman and electronic absorption spectra of bacteriochlorophyll a cation radical

    SciTech Connect (OSTI)

    Misono, Yasuhito; Itoh, Koichi [Waseda Univ., Tokyo (Japan)] [Waseda Univ., Tokyo (Japan); Limanatara, Leenawaty; Koyama, Yasushi [Kwansei Gakuin Univ., Nishinomiya (Japan)] [Kwansei Gakuin Univ., Nishinomiya (Japan)

    1996-02-08

    Resonance Raman and electronic absorption spectra of bacteriocholrophyll a cation radical (BChl a{sup .+}) were recorded in 14 different kinds of solvents. The frequency of the ring-breathing Raman band of BChl a{sup .+} was in the region of 1596-1599 cm{sup -1} in solvents forming the pentacoordinated state in neutral bacteriochlorophyll a (BChl a), while it was in the region of 1584-1588 cm{sup -1} in solvents forming the hexacoordinated state. BChl a{sup .+} exhibited a key absorption band in the regions 546-554 and 557-563 nm in the above penta- and hexa-coordinating solvents. Therefore, it has been concluded that the penta- and hexa-coordinated states are retained even after conversion of BChl a into BChl a{sup .+} (one-electron oxidization). Application of this rule to the case of 2-propanol solution showed transformation from the penta- to the hexa-coordinated state upon one-electron oxidation in this particular solution. The coordination states of BChl a{sup .+} could be correlated with the donor number(DN) and the Taft parameters, {Beta} and {pi}{sup *}, of the solvent: The hexacoordinated state was formed in solvents with DN >= 18 or {Beta} > 0.5 showing higher electron donating power, while the pentacoordinated state was formed in solvents with {pi}{sup *} > 0.65 showing higher dielectric stabilization. 27 refs., 8 figs., 3 tabs.

  7. Boron phosphide under pressure: In situ study by Raman scattering and X-ray diffraction

    SciTech Connect (OSTI)

    Solozhenko, Vladimir L.; Kurakevych, Oleksandr O.; Le Godec, Yann; Kurnosov, Aleksandr V.; Oganov, Artem R.

    2014-07-21

    Cubic boron phosphide, BP, has been studied in situ by X-ray diffraction and Raman scattering up to 55?GPa at 300?K in a diamond anvil cell. The bulk modulus of B{sub 0}?=?174(2) GPa has been established, which is in excellent agreement with our ab initio calculations. The data on Raman shift as a function of pressure, combined with equation-of-state (EOS) data, allowed us to estimate the Grüneisen parameters of the TO and LO modes of zinc-blende structure, ?{sub G}{sup TO?}=?1.26 and ?{sub G}{sup LO?}=?1.13, just like in the case of other A{sup III}B{sup V} diamond-like phases, for which ?{sub G}{sup TO?}>??{sub G}{sup LO?}??1. We also established that the pressure dependence of the effective electro-optical constant ? is responsible for a strong change in relative intensities of the TO and LO modes from I{sub TO}/I{sub LO}???0.25 at 0.1?MPa to I{sub TO}/I{sub LO}???2.5 at 45?GPa, for which we also find excellent agreement between experiment and theory.

  8. Raman Analysis of Perrhenate and Pertechnetate in Alkali Salts and Borosilicate Glasses

    SciTech Connect (OSTI)

    Gassman, Paul L.; McCloy, John S.; Soderquist, Chuck Z.; Schweiger, Michael J.

    2014-01-03

    Sodium borosilicate glasses containing various concentrations of rhenium or technetium were fabricated, and their vibrational spectra studied using a Raman microscope. Spectra were interpreted with reference to new high resolution measurements of alkali pertechnetates and perrhenates NaReO4, KReO4, NaTcO4, and KTcO4. At low concentrations of ReO4- or TcO4-, glass spectra show weak peaks superimposed on a dominant spectrum of glass characteristic of silicate and borate network vibrations. At high concentrations, sharp peaks characteristic of crystal field splitting and C4h symmetry dominate the spectra of glasses, indicating alkali nearby tetrahedral Re or Tc. Often peaks indicative of both the K and Na pertechnetates/ perrhenates are evident in the Raman spectrum, with the latter being favored at high additions of the source chemical, since Na is more prevalent in the glass and ion exchange takes place. These results have significance to immobilization of nuclear waste containing radioactive 99Tc in glass for ultimate disposal.

  9. Distinguishing Unfolding and Functional Conformational Transitions of Calmodulin Using Ultraviolet Resonance Raman Spectroscopy

    SciTech Connect (OSTI)

    Jones, Eric M.; Balakrishnan, G.; Squier, Thomas C.; Spiro, Thomas

    2014-06-14

    Calmodulin (CaM) is a ubiquitous moderator protein for calcium signaling in all eukaryotic cells. This small calcium-binding protein exhibits a broad range of structural transitions, including domain opening and folding-unfolding, that allow it to recognize a wide variety of binding partners in vivo. While the static structures of CaM associated with its various binding activities are fairly well known, it has been challenging to examine the dynamics of transition between these structures in real-time, due to a lack of suitable spectroscopic probes of CaM structure. In this paper, we examine the potential of ultraviolet resonance Raman (UVRR) spectroscopy for clarifying the nature of structural transitions in CaM. We find that the UVRR spectral change (with 229 nm excitation) due to thermal unfolding of CaM is qualitatively different from that associated with opening of the C-terminal domain in response to Ca2+ binding. This spectral difference is entirely due to differences in teritary contacts at the inter-domain tyrosine residue Tyr138, toward which other spectroscopic methods are not sensitive. We conclude that UVRR is ideally suited to identifying the different types of structural transitions in CaM and other proteins with conformation-sensitive tyrosine residues, opening a path to time-resolved studies of CaM dynamics using Raman spectroscopy.

  10. Fiber optic apparatus for detecting molecular species by surface enhanced Raman spectroscopy

    DOE Patents [OSTI]

    Angel, Stanley M. (Livermore, CA); Sharma, Shiv K. (Honolulu, HI)

    1988-01-01

    Optrode apparatus for detecting constituents of a fluid medium includes an optical fiber (13, 13a to 13e) having a metal coating (22, 22a to 22e) on at least a portion of a light transmissive core (17, 17a to 17d). The metal is one, such as silver, gold or copper, which enhances emission of Raman signal frequencies by molecules adsorbed on the surface of the coating when monochromatic probe light of a different frequency is scattered by such molecules and the metal coating is sufficiently thin to transmit light between the absorbed molecules and the core of the fiber. Probe light is directed into one end of the fiber and a detector (16, 16d, 16e) analyzes light emitted from the fiber for Raman frequencies that identify one or more particular molecular species. In one form, the optrode (13e) may function as a working electrode of an electrochemical cell (53) while also serving to detect the products of oxidation or reduction reactions which occur at the electrode surface.

  11. Accelerated Testing of HT-9 with Zirconia Coatings Containing Gallium using Raman Spectroscopy and XPS

    SciTech Connect (OSTI)

    Windisch, Charles F.; Henager, Charles H.; Engelhard, Mark H.; Bennett, Wendy D.

    2009-12-01

    Laser Raman spectroscopy and x-ray photoelectron spectroscopy were used to study the evolution of composition of oxide films in the presence of zirconia coatings on miniature HT-9 alloy specimens subjected to elevated temperature in air. The experiments expanded on previous efforts to develop a quick-screening technique for candidate alloys for cladding materials (HT-9) and actinide-based mixed oxide fuel mixtures (represented by the zirconia coating) by investigating the effect of both coating composition and alloy pretreatment conditions on the high temperature reactions. In particular, the presence of the element Ga (a potential impurity in mixed oxide fuel) in the initial zirconia coating was found to accelerate the rate of oxide growth relative to that of yttria-stabilized zirconia studied previously. In addition, HT-9 samples that were subjected to different thermal pretreatments gave different results. The results suggest that the presence of Ga in a mixed oxide fuel will enhance the corrosion of HT-9 cladding under the conditions of this study, although the extent of enhancement is influenced by thermal pretreatment of the cladding material. The results also demonstrate the need to combine Raman spectroscopy with other techniques, particularly photoelectron spectroscopy, for optimizing composition and/or fabrication conditions of both cladding and oxide fuels for advanced nuclear reactors.

  12. Raman and far ir spectroscopic study of quaternary ammonium polybromide fused salt phases for zinc bromine circulating electrolyte batteries

    SciTech Connect (OSTI)

    Larrabee, J.A.; Graf, K.R.; Grimes, P.G.

    1985-01-01

    The circulating electrolyte zinc bromine battery is an attractive advanced battery system. The electrolyte is a solution of zinc bromide, quaternary ammonium bromides for bromine complexation and added salts to enhance properties. Laser Raman spectroscopy and far infrared spectroscopy were used to characterize the liquid quaternary ammonium polybromide fused salt phases.

  13. Electronic resonance enhanced coherent anti-Stokes Raman scattering technique for detection of combustion species and biological molecules 

    E-Print Network [OSTI]

    Hanna, Sherif Fayez

    2006-10-30

    The application of electronic-resonance enhanced (ERE) coherent anti-Stokes Raman scattering (CARS) for the detection of nitric oxide (NO) and acetylene (C2H2) is experimentally demonstrated and the effects of various parameters on the ERE CARS...

  14. Tuning Gold Nanoparticle Self-Assembly for Optimum Coherent Anti-Stokes Raman Scattering and Second Harmonic Generation Response

    E-Print Network [OSTI]

    Brolo, Alexandre G.

    , PO Box 3065, Victoria, BC, Canada, V8W 3V6, and Department of Electrical and Computer Engineering) techniques: Coherent anti-Stokes Raman scattering (CARS) and second harmonic generation (SHG). The CARS. Maximum signal was observed for 11 NP layers and is attributed to the matching of the CARS signal

  15. Multi-wavelength Raman Spectroscopy of Nanodiamond Particles Paul William May, Philip Overton, James A Smith, and Keith N Rosser

    E-Print Network [OSTI]

    Bristol, University of

    Multi-wavelength Raman Spectroscopy of Nanodiamond Particles Paul William May, Philip Overton significant for lower wavelengths, probably as a result of the increased absorbance by nanodiamond particles of carbon films, including diamond, diamondlike carbon, and nanodiamond particles [1]. For diamond particles

  16. Theoretical study of collinear optical frequency comb generation under multi-wave, transient stimulated Raman scattering in crystals

    SciTech Connect (OSTI)

    Smetanin, S N [A M Prokhorov General Physics Institute, Russian Academy of Sciences, Moscow (Russian Federation)

    2014-11-30

    Using mathematical modelling we have studied the conditions of low-threshold collinear optical frequency comb generation under transient (picosecond) stimulated Raman scattering (SRS) and parametric four-wave coupling of SRS components in crystals. It is shown that Raman-parametric generation of an octave-spanning optical frequency comb occurs most effectively under intermediate, transient SRS at a pump pulse duration exceeding the dephasing time by five-to-twenty times. We have found the optimal values of not only the laser pump pulse duration, but also of the Raman crystal lengths corresponding to highly efficient generation of an optical frequency comb from the second anti-Stokes to the fourth Stokes Raman components. For the KGd(WO{sub 4}){sub 2} (high dispersion) and Ba(NO{sub 3}){sub 2} (low dispersion) crystals pumped at a wavelength of 1.064 ?m and a pulse duration five or more times greater than the dephasing time, the optimum length of the crystal was 0.3 and 0.6 cm, respectively, which is consistent with the condition of the most effective Stokes – anti-Stokes coupling ?kL ? 15, where ?k is the wave detuning from phase matching of Stokes – anti-Stokes coupling, determined by the refractive index dispersion of the SRS medium. (nonlinear optical phenomena)

  17. Optically Controlled Seeding of Raman Forward Scattering and Injection of Electrons in a Self-Modulated Laser-Wakefield Accelerator

    E-Print Network [OSTI]

    Optically Controlled Seeding of Raman Forward Scattering and Injection of Electrons in a Self, Chia-Yi 621, Taiwan 6 Department of Electrical Engineering, National Taiwan University, Taipei 106, Taiwan (Received 5 September 2003; published 20 February 2004) Optical seeding of plasma waves

  18. Depth-resolved confocal micro-Raman spectroscopy for characterizing GaN-based light emitting diode structures

    SciTech Connect (OSTI)

    Chen, Wei-Liang; Lee, Yu-Yang; Chang, Yu-Ming, E-mail: ymchang@ntu.edu.tw [Center for Condensed Matter Sciences, National Taiwan University, 10617 Taipei, Taiwan (China)] [Center for Condensed Matter Sciences, National Taiwan University, 10617 Taipei, Taiwan (China); Chang, Chiao-Yun; Huang, Huei-Min; Lu, Tien-Chang [Department of Photonics, National Chiao Tung University, 30010 Hsinchu, Taiwan (China)] [Department of Photonics, National Chiao Tung University, 30010 Hsinchu, Taiwan (China)

    2013-11-15

    In this work, we demonstrate that depth-resolved confocal micro-Raman spectroscopy can be used to characterize the active layer of GaN-based LEDs. By taking the depth compression effect due to refraction index mismatch into account, the axial profiles of Raman peak intensities from the GaN capping layer toward the sapphire substrate can correctly match the LED structural dimension and allow the identification of unique Raman feature originated from the 0.3 ?m thick active layer of the studied LED. The strain variation in different sample depths can also be quantified by measuring the Raman shift of GaN A{sub 1}(LO) and E{sub 2}(high) phonon peaks. The capability of identifying the phonon structure of buried LED active layer and depth-resolving the strain distribution of LED structure makes this technique a potential optical and remote tool for in operando investigation of the electronic and structural properties of nitride-based LEDs.

  19. Molecular Orientation in Dry and Hydrated Cellulose Fibers: A Coherent Anti-Stokes Raman Scattering Microscopy Study

    E-Print Network [OSTI]

    Potma, Eric Olaf

    Molecular Orientation in Dry and Hydrated Cellulose Fibers: A Coherent Anti-Stokes Raman Scattering the molecular alignment in dry and hydrated cellulose fibers. Two types of cellulose were investigated: natural cellulose I in cotton fibers and regenerated cellulose II in rayon fibers. On the basis of the orientation

  20. Application of scanning angle Raman spectroscopy for determining the location of buried polymer interfaces with tens of nanometer precision

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Damin, Craig A.; Nguyen, Vy H. T.; Niyibizi, Auguste S.; Smith, Emily A.

    2015-02-11

    Near-infrared scanning angle (SA) Raman spectroscopy was utilized to determine the interface location in bilayer films (a stack of two polymer layers) of polystyrene (PS) and polycarbonate (PC). Finite-difference-time-domain (FDTD) calculations of the sum square electric field (SSEF) for films with total bilayer thicknesses of 1200–3600 nm were used to construct models for simultaneously measuring the film thickness and the location of the buried interface between the PS and PC layers. Samples with total thicknesses of 1320, 1890, 2300, and 2750 nm and varying PS/PC interface locations were analyzed using SA Raman spectroscopy. Comparing SA Raman spectroscopy and optical profilometrymore »measurements, the average percent difference in the total bilayer thickness was 2.0% for films less than ~2300 nm thick. The average percent difference in the thickness of the PS layer, which reflects the interface location, was 2.5% when the PS layer was less than ~1800 nm. The SA Raman spectroscopy has been shown to be a viable, non-destructive method capable of determining the total bilayer thickness and buried interface location for bilayer samples consisting of thin polymer films with comparable indices of refraction.« less

  1. Influence of glass polymerisation and oxidation on micro-Raman water analysis in alumino-silicate glasses

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Influence of glass polymerisation and oxidation on micro-Raman water analysis in alumino-silicate glasses Maxime Merciera, Andrea Di Muroab , Daniele Giordanoc , Nicole Métricha , Priscille Lesned of an accurate analytical procedure for determination of dissolved water in complex alumino-silicate glasses via

  2. Resonance Raman Analysis of the Mechanism of Energy Storage and Chromophore Distortion in the Primary Visual Photoproduct

    E-Print Network [OSTI]

    Chang, Belinda

    Resonance Raman Analysis of the Mechanism of Energy Storage and Chromophore Distortion modes and their relation to energy storage in the primary photoproduct. Low-temperature (77 K) resonance interactions of the 9- and 13-methyl groups with surrounding residues. This distortion stores light energy

  3. Ultraviolet (UV) Raman Spectroscopy Study of the Soret Effect in High-Pressure CO2-Water Solutions

    SciTech Connect (OSTI)

    Windisch, Charles F.; Maupin, Gary D.; McGrail, B. Peter

    2012-07-01

    Spatially resolved deep-UV Raman spectroscopy was applied to solutions of CO2 and H2O or D2O subject to a temperature gradient in a thermally regulated high-pressure concentric-tube Raman cell in an attempt to measure a Soret effect in the vicinity of the critical point of CO2. Although Raman spectra of solutions of CO2 dissolved in D2O, at 10 MPa and temperatures near the critical point of CO2, had adequate signal-to-noise and spatial resolution to observe a Soret effect with a Soret coefficient with magnitude |ST| > 0.03, no evidence for an effect of this size was obtained for applied temperature gradients up to 19 C. In contrast, the concentration of CO2 dissolved in H2O was shown to vary significantly across the temperature gradient when excess CO2 was present, but the results could be explained simply by the variation in CO2 solubility over the temperature range and not to kinetic factors. For mixtures of D2O dissolved in scCO2 at 10 MPa and temperatures close to the critical point of CO2, the Raman peaks for D2O were too weak to measure with confidence even at the limit of D2O solubility.

  4. Optical transitions and multiphonon Raman scattering of Cu doped ZnO and MgZnO ceramics

    E-Print Network [OSTI]

    McCluskey, Matthew

    Optical transitions and multiphonon Raman scattering of Cu doped ZnO and MgZnO ceramics Jesse Huso doped ZnO and MgZnO ceramics were created via a process of cold pressing and annealing, and their optical properties and phonon dynamics were studied. It was found that the ceramics exhibit infrared

  5. In situ high P-T Raman spectroscopy and laser heating of carbon dioxide Mario Santoro,a)

    E-Print Network [OSTI]

    Lin, Jung-Fu "Afu"

    In situ high P-T Raman spectroscopy and laser heating of carbon dioxide Mario Santoro,a) Jung interpretation of the high P-T phase diagram of carbon dioxide. Furthermore, our approach opens a new way energy of the electrons. Solid-solid phase transitions thus occur to minimize the overall energy

  6. A novel micro-Raman technique to detect and characterize 4H-SiC stacking faults

    SciTech Connect (OSTI)

    Piluso, N. Camarda, M.; La Via, F.

    2014-10-28

    A novel Micro-Raman technique was designed and used to detect extended defects in 4H-SiC homoepitaxy. The technique uses above band-gap high-power laser densities to induce a local increase of free carriers in undoped epitaxies (n?Raman mode. The Raman shift of the LO phonon-plasmon-coupled mode (LOPC) increases as the free carrier density increases. Crystallographic defects lead to scattering or recombination of the free carriers which results in a loss of coupling with the LOPC, and in a reduction of the Raman shift. Given that the LO phonon-plasmon coupling is obtained thanks to the free carriers generated by the high injection level induced by the laser, we named this technique induced-LOPC (i-LOPC). This technique allows the simultaneous determination of both the carrier lifetime and carrier mobility. Taking advantage of the modifications on the carrier lifetime induced by extended defects, we were able to determine the spatial morphology of stacking faults; the obtained morphologies were found to be in excellent agreement with those provided by standard photoluminescence techniques. The results show that the detection of defects via i-LOPC spectroscopy is totally independent from the stacking fault photoluminescence signals that cover a large energy range up to 0.7?eV, thus allowing for a single-scan simultaneous determination of any kind of stacking fault. Combining the i-LOPC method with the analysis of the transverse optical mode, the micro-Raman characterization can determine the most important properties of unintentionally doped film, including the stress status of the wafer, lattice impurities (point defects, polytype inclusions) and a detailed analysis of crystallographic defects, with a high spectral and spatial resolution.

  7. Rabi Waves and Peculiarities of Raman Scattering in Carbon Nanotubes, Produced by High Energy Ion Beam Modification of Diamond Single Crystals

    E-Print Network [OSTI]

    Dmitry Yearchuck; Alla Dovlatova

    2011-03-06

    QED-model for multichain coupled qubit system, proposed in \\cite{Part1}, was confirmed by Raman scattering studies of carbon zigzag-shaped nanotubes, produced by high energy ion beam modification of natural diamond single crystals. New quantum optics phenomenon - Rabi waves - has been experimentally identified for the first time. Raman spectra in perfect quasi-1D carbon nanotubes are quite different in comparison with well known Raman spectra in 2D carbon nanotubes of larger diameter. They characterized by vibronic mode of Su-Schriffer-Heeger $\\sigma$-polaron lattice and its revival part in frequency representation, which is the consequence of Rabi wave packet formation.

  8. Raman microscopy as a defect microprobe for hydrogen bonding characterization in materials used in fusion applications

    E-Print Network [OSTI]

    Pardanaud, Cédric; Martin, Céline; Roubin, Pascale; Pegourié, Bernard; Oberkofler, Martin; Köppen, Martin; Dittmar, Timo; Linsmeier, Christian

    2014-01-01

    We present the Raman microscopy ability to detect and characterize the way hydrogen is bonded with elements that will be used for ITER's plasma facing components. For this purpose we first use hydrogenated amorphous carbon samples, formed subsequently to plasma-wall interactions (hydrogen implantation, erosion, deposition...) occurring inside tokamaks, to demonstrate how this technique can be used to retrieve useful information. We pay attention in identifying which spectroscopic parameters are sensitive to the local structure (sp 3 /sp 2) and which gives information on the hydrogen content using isothermal and linear temperature ramp studies on reference samples produced by plasma enhanced chemical vapor deposition. We then focus on the possibility to use this fast, non-destructive and non-contact technique to characterize the influence of hydrogen isotope implantation in few nanometers of graphite and beryllium as C is still used in the JT-60 tokamak and Be is used in JET and will be used as plasma-facing c...

  9. Final Technical Report "Study of Efficiency of Raman Backscattering Amplification in Plasma"

    SciTech Connect (OSTI)

    Suckewer, Szymon

    2014-03-31

    General : Our major scientific achievements in Raman Backscattering (RBS) amplification and compression of short laser pulses in plasma. The laser system based on RBS steps in where the current technology of chirped pulse amplification (CPA) (extremely successful in developing ultra-short and ultra-intense laser pulses in last 2 decades) becomes difficult and very expensive to apply. Good base for such RBS laser was created by our recent experiments, which were supported by GPS grants. The main objective of the present grant was: improvement efficiency of energy transfer from pump to seed. The results surpassed our expectations; we improved the efficiency of energy transfer from pump to seed by a factor of 6 compared to the best of our previous results and amplified seed pulse compressed down to about 50 fsec.

  10. Demonstration of Detuning and Wavebreaking Effects on Raman Amplification Effciency in Plasma

    SciTech Connect (OSTI)

    Yampolsky, N. A.; Fisch, N. J.; Malkin, V. M.; Valeo, E. J.; Lindberg, R.; Wurtele, J.; Ren, J.; Li, S.; Morozov, A.; Suckewer, S.

    2008-11-06

    A plasma-based resonant backward Raman amplifier/compressor for high power amplification of short laser pulses might, under ideal conditions, convert as much as 90% of the pump energy to the seed pulse. While the theoretical highest possible efficiency of this scheme has not yet been achieved, larger efficiencies than ever before obtained experimentally (6.4%) are now being reported, and these efficiencies are accompanied by strong pulse compression. Based on these recent extensive experiments, it is now possible to deduce that the experimentally realized efficiency of the amplifier is likely constrained by two factors, namely the pump chirp and the plasma wavebreaking, and that these experimental observations may likely involve favorable compensation between the chirp of the laser and the density variation of the mediating plasma. Several methods for further improvement of the amplifier e?ciency in current experiments are suggested.

  11. Suppression of the four-wave mixing amplification via Raman absorption

    E-Print Network [OSTI]

    Romanov, Gleb; Novikova, I

    2015-01-01

    We propose a method to controllably suppress the effect of the four-wave mixing caused by the coupling of the strong control optical field to both optical transitions in the $\\Lambda$ system under the conditions of electromagnetically induced transparency. At sufficiently high atomic density, this process leads to amplification of a weak optical signal field, that is detrimental for the fidelity of any EIT-based quantum information applications. Here we show that an additional absorption resonance centered around the idler field frequency, generated in such a four-wave mixing process, may efficiently suppress the unwanted signal amplification without affecting properties of the EIT interaction. We discuss the possibility of creating such tunable absorption using two-photon Raman absorption resonances in the other Rb isotope, and present some preliminary experimental results.

  12. With a ground-based Doppler lidar on the Northwest side of a wind farm in the Tehachapi Pass of California, measurements were collected for repeating sector sweeps to the Northwest, measuring up to

    E-Print Network [OSTI]

    With a ground-based Doppler lidar on the Northwest side of a wind farm in the Tehachapi Pass. The method being explored uses real-time measurements of wind velocity made upstream of the wind farm and models the power output of a turbine in the wind farm as though it were located upstream. This determines

  13. ESTIMATION OF THE LIDAR OVERLAP FUNCTION BY NON-LINEAR A. C. Povey1, R. G. Grainger1, D. M. Peters1, J. L. Agnew2, and D. Rees3

    E-Print Network [OSTI]

    Oxford, University of

    for the extinction profile, constrained by aerosol opti- cal thickness. Considering simulated data, the scheme is successful even where the aerosol profile deviates sig- nificantly from the simple model assumed. Application. Further, many methods of lidar analysis are designed to only consider regions where the overlap function

  14. Electron paramagnetic resonance and Raman spectroscopy studies on carbon-doped MgB{sub 2} superconductor nanomaterials

    SciTech Connect (OSTI)

    Bateni, Ali; Somer, Mehmet E-mail: msomer@ku.edu.tr; Erdem, Emre E-mail: msomer@ku.edu.tr; Repp, Sergej; Weber, Stefan; Acar, Selcuk; Kokal, Ilkin; Häßler, Wolfgang

    2015-04-21

    Undoped and carbon-doped magnesium diboride (MgB{sub 2}) samples were synthesized using two sets of mixtures prepared from the precursors, amorphous nanoboron, and as-received amorphous carbon-doped nanoboron. The microscopic defect structures of carbon-doped MgB{sub 2} samples were systematically investigated using X-ray powder diffraction, Raman and electron paramagnetic resonance spectroscopy. Mg vacancies and C-related dangling-bond active centers could be distinguished, and sp{sup 3}-hybridized carbon radicals were detected. A strong reduction in the critical temperature T{sub c} was observed due to defects and crystal distortion. The symmetry effect of the latter is also reflected on the vibrational modes in the Raman spectra.

  15. Multiferroic CuCrO? under high pressure: In situ X-ray diffraction and Raman spectroscopic studies

    SciTech Connect (OSTI)

    Garg, Alka B. Mishra, A. K.; Pandey, K. K.; Sharma, Surinder M.

    2014-10-07

    The compression behavior of delafossite compound CuCrO? has been investigated by in situ x-ray diffraction (XRD) and Raman spectroscopic measurements up to 23.2 and 34 GPa, respectively. X-ray diffraction data show the stability of ambient rhombohedral structure up to ~23 GPa. Material shows large anisotropy in axial compression with c-axis compressibility, ?{sub c} = 1.26 × 10?³(1) GPa?¹ and a-axis compressibility, ?{sub a} = 8.90 × 10?³(6) GPa?¹. Our XRD data show an irreversible broadening of diffraction peaks. Pressure volume data when fitted to 3rd order Birch-Murnaghan equation of state give the value of bulk modulus, B? = 156.7(2.8) GPa with its pressure derivative, B?{sup ’} as 5.3(0.5). All the observed vibrational modes in Raman measurements show hardening with pressure. Appearance of a new mode at ~24 GPa indicates the structural phase transition in the compound. Our XRD and Raman results indicate that CuCrO{sub 2} may be transforming to an ordered rocksalt type structure under compression.

  16. Stimulated Raman scattering of beat wave of two counter-propagating X-mode lasers in a magnetized plasma

    SciTech Connect (OSTI)

    Verma, Kanika; Sajal, Vivek Varshney, Prateek; Kumar, Ravindra; Sharma, Navneet K.

    2014-02-15

    Effects of transverse static magnetic field on stimulated Raman scattering (SRS) of the beat wave excited by two counter-propagating lasers are studied. Two counter-propagating lasers with frequency difference, ?{sub 1}??{sub 2}?2?{sub p}, drive a non resonant space charge beat mode at wave number k{sup ?}{sub 0}?k{sup ?}{sub 1}+k{sup ?}{sub 2} in a plasma, where k{sup ?}{sub 1} and k{sup ?}{sub 2} are wave vectors of lasers having frequencies ?{sub 1} and ?{sub 2}, respectively. The driven beat wave acts as a pump for SRS and excites parametrically a pair of plasma wave (?,k{sup ?}) and side band electromagnetic wave (?{sub 3},k{sup ?}{sub 3}) propagating in the sideward direction in such a way that momentum remains conserved. The growth rate of Raman process is maximum for side scattering at ?{sub s}=?/2 for lower values of applied magnetic field (?1?kG), which can be three fold by applying magnetic field ?5.0?kG. Thus, optimum value of magnetic field can be utilized to achieve maximum electron acceleration in counter propagating geometry of beat wave acceleration by reducing the growth rate of Raman process.

  17. Surface-Enhanced Raman Scattering (SERS) for Detection in Immunoassays: applications, fundamentals, and optimization

    SciTech Connect (OSTI)

    Jeremy Daniel Driskell

    2006-08-09

    Immunoassays have been utilized for the detection of biological analytes for several decades. Many formats and detection strategies have been explored, each having unique advantages and disadvantages. More recently, surface-enhanced Raman scattering (SERS) has been introduced as a readout method for immunoassays, and has shown great potential to meet many key analytical figures of merit. This technology is in its infancy and this dissertation explores the diversity of this method as well as the mechanism responsible for surface enhancement. Approaches to reduce assay times are also investigated. Implementing the knowledge gained from these studies will lead to a more sensitive immunoassay requiring less time than its predecessors. This dissertation is organized into six sections. The first section includes a literature review of the previous work that led to this dissertation. A general overview of the different approaches to immunoassays is given, outlining the strengths and weaknesses of each. Included is a detailed review of binding kinetics, which is central for decreasing assay times. Next, the theoretical underpinnings of SERS is reviewed at its current level of understanding. Past work has argued that surface plasmon resonance (SPR) of the enhancing substrate influences the SERS signal; therefore, the SPR of the extrinsic Raman labels (ERLs) utilized in our SERS-based immunoassay is discussed. Four original research chapters follow the Introduction, each presented as separate manuscripts. Chapter 2 modifies a SERS-based immunoassay previously developed in our group, extending it to the low-level detection of viral pathogens and demonstrating its versatility in terms of analyte type, Chapter 3 investigates the influence of ERL size, material composition, and separation distance between the ERLs and capture substrate on the SERS signal. This chapter links SPR with SERS enhancement factors and is consistent with many of the results from theoretical treatments of SPR and SERS. Chapter 4 introduces a novel method of reducing sample incubation time via capture substrate rotation. Moreover, this work led to a method of virus quantification without the use of standards. Chapter 5 extends the methodology developed in Chapter 4 to both the antigen and ERL labeling step to perform assays with improved analytical performance in less time than can be accomplished in diffusion controlled assays. This dissertation concludes with a general summary and speculates on the future of this exciting approach to carrying out immunoassays.

  18. ARM - Measurement - Lidar polarization

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Comments?govInstrumentsnoaacrnBarrow, Alaska Outreach Home Roomparticle sizefractiongovMeasurementsLatent

  19. Raman Based Process Monitor For Continuous Real-Time Analysis Of High Level Radioactive Waste Components

    SciTech Connect (OSTI)

    Bryan, Samuel A.; Levitskaia, Tatiana G.; Schlahta, Stephan N.

    2008-05-27

    ABSTRACT A new monitoring system was developed at Pacific Northwest National Laboratory (PNNL) to quickly generate real-time data/analysis to facilitate a timely response to the dynamic characteristics of a radioactive high level waste stream. The developed process monitor features Raman and Coriolis/conductivity instrumentation configured for the remote monitoring, MatLab-based chemometric data processing, and comprehensive software for data acquisition/storage/archiving/display. The monitoring system is capable of simultaneously and continuously quantifying the levels of all the chemically significant anions within the waste stream including nitrate, nitrite, phosphate, carbonate, chromate, hydroxide, sulfate, and aluminate. The total sodium ion concentration was also determined independently by modeling inputs from on-line conductivity and density meters. In addition to the chemical information, this monitoring system provides immediate real-time data on the flow parameters, such as flow rate and temperature, and cumulative mass/volume of the retrieved waste stream. The components and analytical tools of the new process monitor can be tailored for a variety of complex mixtures in chemically harsh environments, such as pulp and paper processing liquids, electroplating solutions, and radioactive tank wastes. The developed monitoring system was tested for acceptability before it was deployed for use in Hanford Tank S-109 retrieval activities. The acceptance tests included performance inspection of hardware, software, and chemometric data analysis to determine the expected measurement accuracy for the different chemical species that are encountered during S-109 retrieval.

  20. Raman Based Process Monitor for Continuous Real-Time Analysis Of High Level Radioactive Waste Components

    SciTech Connect (OSTI)

    Bryan, S.; Levitskaia, T.; Schlahta, St. [Pacific Northwest National Laboratory, Richland, Washington (United States)

    2008-07-01

    A new monitoring system was developed at Pacific Northwest National Laboratory (PNNL) to quickly generate real-time data/analysis to facilitate a timely response to the dynamic characteristics of a radioactive high level waste stream. The developed process monitor features Raman and Coriolis/conductivity instrumentation configured for the remote monitoring, MatLab-based chemometric data processing, and comprehensive software for data acquisition/storage/archiving/display. The monitoring system is capable of simultaneously and continuously quantifying the levels of all the chemically significant anions within the waste stream including nitrate, nitrite, phosphate, carbonate, chromate, hydroxide, sulfate, and aluminate. The total sodium ion concentration was also determined independently by modeling inputs from on-line conductivity and density meters. In addition to the chemical information, this monitoring system provides immediate real-time data on the flow parameters, such as flow rate and temperature, and cumulative mass/volume of the retrieved waste stream. The components and analytical tools of the new process monitor can be tailored for a variety of complex mixtures in chemically harsh environments, such as pulp and paper processing liquids, electroplating solutions, and radioactive tank wastes. The developed monitoring system was tested for acceptability before it was deployed for use in Hanford Tank S-109 retrieval activities. The acceptance tests included performance inspection of hardware, software, and chemometric data analysis to determine the expected measurement accuracy for the different chemical species that are encountered during S-109 retrieval. (authors)

  1. Influence of reabsorption and reemission on stimulated Raman scattering of polymethine dyes in multiple scattering media

    SciTech Connect (OSTI)

    Yashchuk, V P; Komyshan, A O; Smaliuk, A P; Prygodiuk, O A; Ishchenko, A A; Olkhovyk, L A

    2013-12-31

    It is shown that reabsorption of the luminescence radiation in the range of its overlapping with the absorption spectrum and the following reemission to a long-wavelength range may noticeably affect the process of stimulated Raman scattering (SRS) in polymethine dyes in multiple scattering media (MSM). This is related to the fact that SRS in such media occurs jointly with the random lasing (RL), which favors SRS and makes up with it a united nonlinear process. Reemission into the long-wavelength spectrum range amplified in MSM causes the RL spectrum to shift to longer wavelengths and initiates the long-wavelength band of RL, in which a main part of the lasing energy is concentrated. This weakens or completely stops the SRS if the band is beyond the range of possible spectral localisation of Stokes lines. This process depends on the efficiency of light scattering, dye concentration, temperature and pump intensity; hence, there exist optimal values of these parameters for obtaining SRS in MSM. (nonlinear optical phenomena)

  2. Field testing the Raman gas composition sensor for gas turbine operation

    SciTech Connect (OSTI)

    Buric, M.; Chorpening, B.; Mullem, J.; Ranalli, J.; Woodruff, S.

    2012-01-01

    A gas composition sensor based on Raman spectroscopy using reflective metal lined capillary waveguides is tested under field conditions for feed-forward applications in gas turbine control. The capillary waveguide enables effective use of low powered lasers and rapid composition determination, for computation of required parameters to pre-adjust burner control based on incoming fuel. Tests on high pressure fuel streams show sub-second time response and better than one percent accuracy on natural gas fuel mixtures. Fuel composition and Wobbe constant values are provided at one second intervals or faster. The sensor, designed and constructed at NETL, is packaged for Class I Division 2 operations typical of gas turbine environments, and samples gas at up to 800 psig. Simultaneous determination of the hydrocarbons methane, ethane, and propane plus CO, CO2, H2O, H2, N2, and O2 are realized. The capillary waveguide permits use of miniature spectrometers and laser power of less than 100 mW. The capillary dimensions of 1 m length and 300 μm ID also enable a full sample exchange in 0.4 s or less at 5 psig pressure differential, which allows a fast response to changes in sample composition. Sensor operation under field operation conditions will be reported.

  3. Analysis of organic pollutant degradation in pulsed plasma by coherent anti-Stokes Raman spectroscopy

    SciTech Connect (OSTI)

    Bratescu, Maria Antoneta; Hieda, Junko; Umemura, Tomonari; Saito, Nagahiro; Takai, Osamu

    2011-05-15

    The degradation of p-benzoquinone (p-BQ) in water was investigated by the coherent anti-Stokes Raman spectroscopy (CARS) method, in which the change of the anti-Stokes signal intensity corresponding to the vibrational transitions of the molecule is monitored during and after solution plasma processing (SPP). In the beginning of SPP treatment, the CARS signal intensity of the ring vibrational molecular transitions at 1233 and 1660 cm{sup -1} increases under the influence of the electric field of the plasma, depending on the delay time between the plasma pulse and the laser firing pulse. At the same time, the plasma contributes to the degradation of p-BQ molecules by generating hydrogen and hydroxyl radicals, which decompose p-BQ into different carboxylic acids. After SPP, the CARS signal intensity of the vibrational bands of p-BQ ceased and the degradation of p-BQ was confirmed by UV-visible absorption spectroscopy and liquid chromatography analysis.

  4. Stokes--anti-Stokes Correlations in Raman Scattering from Diamond Membranes

    E-Print Network [OSTI]

    Kasperczyk, Mark; Neu, Elke; Maletinsky, Patrick; Novotny, Lukas

    2015-01-01

    We investigate the arrival statistics of Stokes (S) and anti-Stokes (aS) Raman photons generated in diamond membranes. Strong quantum correlations between the S and aS signals are observed, which implies that the two processes share the same phonon, that is, the phonon excited by the S process is consumed in the aS process. We show that the intensity cross-correlation $g_{\\rm S,aS}^{(2)}(0)$, which describes the simultaneous detection of Stokes and anti-Stokes photons, decreases steadily with laser power as $1/{\\rm P_L}$. Contrary to many other material systems, diamond exhibits a maximum $g_{\\rm S,aS}^{(2)}(0)$ at very low pump powers, implying that the Stokes-induced aS photons outnumber the thermally generated aS photons. On the other hand, the coincidence rate shows a quadratic plus cubic power dependence, which indicates a departure from the Stokes-induced anti-Stokes process.

  5. Low-frequency Raman 'fingerprints' of two-dimensional metal dichalcogenide layer stacking configurations

    SciTech Connect (OSTI)

    Puretzky, Alexander A; Liang, Liangbo; Li, Xufan; Xiao, Kai; Wang, Kai; Mahjouri-Samani, Masoud; Basile, Leonardo; Idrobo Tapia, Juan Carlos; Sumpter, Bobby G; Meunier, Vincent; Geohegan, David B

    2015-01-01

    Stacked monolayers of two-dimensional (2D) materials present a new class of hybrid materials with tunable optoelectronic properties determined by their stacking orientation, order, and atomic registry. Atomic-resolution Z-contrast scanning transmission electron microscopy (AR-Z-STEM) and electron energy loss spectroscopy (EELS) can be used to determine the exact atomic registration between different layers, in few-layer 2D stacks, however fast optical characterization techniques are essential for rapid development of the field. Here, using two- and three-layer MoSe2 and WSe2 crystals synthesized by chemical vapor deposition we show that the generally unexplored low frequency (LF) Raman modes (< 50 cm-1) that originate from interlayer vibrations can serve as fingerprints to characterize not only the number of layers, but also their stacking configurations. Ab initio calculations and group theory analysis corroborate the experimental assignments determined by AR-Z-STEM and show that the calculated LF mode fingerprints are related to the 2D crystal symmetries.

  6. Anomalous junctions characterized by Raman spectroscopy in Si{sub x}Ge{sub 1?x} nanowires with axially degraded components

    SciTech Connect (OSTI)

    Xia, Minggang, E-mail: xiamg@mail.xjtu.edu.cn [Laboratory of Nanostructure and Physics Properties, and MOE Key Laboratory for Non-equilibrium Synthesis and Modulation of Condensed Matter, School of Science, Xi'an Jiaotong University, 710049 (China); Department of Optical Information Science and Technology, School of Science, Xi'an Jiaotong University, 710049 (China); Han, Jinyun; Cheng, Zhaofang; Liang, Chunping; Zhang, Shengli [Laboratory of Nanostructure and Physics Properties, and MOE Key Laboratory for Non-equilibrium Synthesis and Modulation of Condensed Matter, School of Science, Xi'an Jiaotong University, 710049 (China); Department of Applied Physics, School of Science, Xi'an Jiaotong University, Shaanxi 710049 (China)

    2014-09-08

    The characterization of junctions in nanowires by high-resolution transmission electron microscopy with spherical aberration correction is tricky and tedious. Many disadvantages also exist, including rigorous sample preparation and structural damage inflicted by high-energy electrons. In this work, we present a simple, low-cost, and non-destructive Raman spectroscopy method of characterizing anomalous junctions in nanowires with axially degraded components. The Raman spectra of Si{sub x}Ge{sub 1?x} nanowires with axially degraded components are studied in detail using a confocal micro-Raman spectrometer. Three Raman peaks (?{sub Si–Si}?=?490?cm{sup ?1}, ?{sub Si–Ge}?=?400?cm{sup ?1}, and ?{sub Ge–Ge}?=?284?cm{sup ?1}) up-shift with increased Si content. This up-shift originates in the bond compression induced by a confined effect on the radial direction of nanowire. The anomalous junctions in Si{sub x}Ge{sub 1?x} nanowires with axially degraded components are then observed by Raman spectroscopy and verified by transmission electron microscopy energy-dispersive X-ray spectroscopy. The anomalous junctions of Si{sub x}Ge{sub 1?x} nanowires with axially degraded components are due to the vortex flow of inlet SiH{sub 4} and GeH{sub 4} gas in their synthesis. The anomalous junctions can be used as raw materials for fabricating devices with special functions.

  7. Raman Scattering Sensor for Control of the Acid Alkylation Process in Gasoline Production

    SciTech Connect (OSTI)

    Uibel, Rory, H.; Smith, Lee M.; Benner, Robert, E.

    2006-04-19

    Gasoline refineries utilize a process called acid alkylation to increase the octane rating of blended gasoline, and this is the single most expensive process in the refinery. For process efficiency and safety reasons, the sulfuric acid can only be used while it is in the concentration range of 98 to 86 %. The conventional technique to monitor the acid concentration is time consuming and is typically conducted only a few times per day. This results in running higher acid concentrations than they would like to ensure that the process proceeds uninterrupted. Maintaining an excessively high acid concentration costs the refineries millions of dollars each year. Using SBIR funding, Process Instruments Inc. has developed an inline sensor for real time monitoring of acid concentrations in gasoline refinery alkylation units. Real time data was then collected over time from the instrument and its responses were matched up with the laboratory analysis. A model was then developed to correlate the laboratory acid values to the Raman signal that is transmitted back to the instrument from the process stream. The instrument was then used to demonstrate that it could create real-time predictions of the acid concentrations. The results from this test showed that the instrument could accurately predict the acid concentrations to within ~0.15% acid strength, and this level of prediction proved to be similar or better then the laboratory analysis. By utilizing a sensor for process monitoring the most economic acid concentrations can be maintained. A single smaller refinery (50,000 barrels/day) estimates that they should save over $120,000/year, with larger refineries saving considerably more.

  8. Determination of saccharides and ethanol from biomass conversion using Raman spectroscopy: Effects of pretreatment and enzyme composition

    SciTech Connect (OSTI)

    Shih, Chien-Ju

    2010-05-16

    This dissertation focuses on the development of facile and rapid quantitative Raman spectroscopy measurements for the determination of conversion products in producing bioethanol from corn stover. Raman spectroscopy was chosen to determine glucose, xylose and ethanol in complex hydrolysis and fermentation matrices. Chapter 1 describes the motives and main goals of this work, and includes an introduction to biomass, commonly used pretreatment methods, hydrolysis and fermentation reactions. The principles of Raman spectroscopy, its advantages and applications related to biomass analysis are also illustrated. Chapter 2 and 3 comprise two published or submitted manuscripts, and the thesis concludes with an appendix. In Chapter 2, a Raman spectroscopic protocol is described to study the efficiency of enzymatic hydrolysis of cellulose by measuring the main product in hydrolysate, glucose. Two commonly utilized pretreatment methods were investigated in order to understand their effect on glucose measurements by Raman spectroscopy. Second, a similar method was set up to determine the concentration of ethanol in fermentation broth. Both of these measurements are challenged by the presence of complex matrices. In Chapter 3, a quantitative comparison of pretreatment protocols and the effect of enzyme composition are studied using systematic methods. A multipeak fitting algorithm was developed to analyze spectra of hydrolysate containing two analytes: glucose and xylose. Chapter 4 concludes with a future perspective of this research area. An appendix describes a convenient, rapid spectrophotometric method developed to measure cadmium in water. This method requires relatively low cost instrumentation and can be used in microgravity, such as space shuttles or the International Space Station. This work was performed under the supervision of Professor Marc Porter while at Iowa State University. Research related to producing biofuel from bio-renewable resources, especially bioethanol from biomass, has grown significantly in the past decade due to the high demand and rising costs of fossil fuels. More than 3 percent of the energy consumption in the U.S. is derived from renewable biomass, mostly through industrial heat and steam production by the pulp and paper industry, and electricity generation from municipal solid waste (MSW) and forest industry residues. The utilization of food-based biomass to make fuels has been widely criticized because it may increase food shortages throughout the world and raise the cost of food. Thus, nonfood-based and plentiful lignocellulosic feedstocks, such as corn stover, perennial grass, bagasse, sorghum, wheat/rice straw, herbaceous and woody crops, have great potential to be new bio-renewable sources for energy production. Given that many varieties of biomass are available, there is need for a rapid, simple, high-throughput method to screen the conversion of many plant varieties. The most suitable species for each geographic region must be determined, as well as the optimal stage of harvest, impacts of environmental conditions (temperature, soil, pH, etc.). Various genetically modified plants should be studied in order to establish the desired biomass in bioethanol production. The main screening challenge, however, is the complexity of plant cell wall structures that make reliable and sensitive analysis difficult. To date, one of the most popular methods to produce lignocellulosic ethanol is to perform enzymatic hydrolysis followed by fermentation of the hydrolysate with yeast. There are several vital needs related to the field of chemistry that have been suggested as primary research foci needed to effectively improve lignocellulosic ethanol production. These topics include overcoming the recalcitrance of cellulosic biomass, the pervasiveness of pretreatment, advanced biological processing and better feedstocks. In this thesis, a novel approach using Raman spectroscopy has been developed to address important issues related to bioethanol generation, which will aid the research aimed to solve the topics m

  9. Spatially dependent Rabi oscillations: An approach to sub-diffraction-limited coherent anti-Stokes Raman-scattering microscopy

    SciTech Connect (OSTI)

    Beeker, Willem P.; Lee, Chris J.; Boller, Klaus-Jochen; Gross, Petra; Cleff, Carsten; Fallnich, Carsten; Offerhaus, Herman L.; Herek, Jennifer L.

    2010-01-15

    We present a theoretical investigation of coherent anti-Stokes Raman scattering (CARS) that is modulated by periodically depleting the ground-state population through Rabi oscillations driven by an additional control laser. We find that such a process generates optical sidebands in the CARS spectrum and that the frequency of the sidebands depends on the intensity of the control laser light field. We show that analyzing the sideband frequency upon scanning the beams across the sample allows one to spatially resolve emitter positions where a spatial resolution of 65 nm, which is well below the diffraction limit, can be obtained.

  10. Formation of a heteronuclear tetramer A{sub 3}B via Efimov-resonance-assisted stimulated Raman adiabatic passage

    SciTech Connect (OSTI)

    Li Guanqiang; Peng Ping [Faculty of Science, Shaanxi University of Science and Technology, 710021 Xi'an (China)

    2011-04-15

    We investigate the formation of a heteronuclear tetramer A{sub 3}B by an Efimov-resonance-assisted stimulated Raman adiabatic passage scheme, which is considered a viable means of creating the homonuclear tetramer A{sub 4}[H. Jing and Y. Jiang, Phys. Rev. A 77, 065601 (2008)]. The atom-molecule dark-state solution for the system is derived, and the adiabatic conversion from atoms to heteronuclear tetramers is studied via the concept of adiabatic fidelity. In addition, the effects of external field parameters (including Rabi pulse strength, width, and single photon detuning) on the conversion are discussed.

  11. Enhancement of surface phonon modes in the Raman spectrum of ZnSe nanoparticles on adsorption of 4-mercaptopyridine

    SciTech Connect (OSTI)

    Islam, Syed K.; Lombardi, John R.

    2014-02-21

    By chemically etching a thin film of crystalline ZnSe with acid, we observe a strong Raman enhancement of the surface phonon modes of ZnSe on adsorption of a molecule (4-mercaptopyridine). The surface is composed of oblate hemi-ellipsoids, which has a large surface-to-bulk ratio. The assignment of the observed modes (at 248 and 492 cm{sup ?1}) to a fundamental and first overtone of the surface optical mode is consistent with observations from high-resolution electron energy loss spectroscopy as well as calculations.

  12. Structural phase transition of ternary dielectric SmGdO{sub 3}: Evidence from angle dispersive x-ray diffraction and Raman spectroscopic studies

    SciTech Connect (OSTI)

    Sharma, Yogesh E-mail: satya504@gmail.com Sahoo, Satyaprakash E-mail: satya504@gmail.com Misra, Pankaj; Pavunny, Shojan P.; Katiyar, Ram S. E-mail: satya504@gmail.com; Mishra, A. K.; Dwivedi, Abhilash; Sharma, S. M.

    2015-03-07

    High-pressure synchrotron based angle dispersive x-ray diffraction (ADXRD) studies were carried out on SmGdO{sub 3} (SGO) up to 25.7?GPa at room temperature. ADXRD results indicated a reversible pressure-induced phase transition from ambient monoclinic to hexagonal phase at ?8.9?GPa. The observed pressure-volume data were fitted with the third order Birch-Murnaghan equation of state yielding zero pressure bulk modulus B{sub 0}?=?132(22) and 177(9) GPa for monoclinic (B-type) and hexagonal (A-type) phases, respectively. Pressure dependent micro-Raman spectroscopy further confirmed the monoclinic to hexagonal phase transition at about 5.24?GPa. The mode Grüneisen parameters and pressure coefficients for different Raman modes corresponding to each individual phases of SGO were calculated using pressure dependent Raman mode analysis.

  13. Raman scattering as a tool for the evaluation of strain in GaN/AlN quantum dots: The effect of capping

    SciTech Connect (OSTI)

    Cros, A.; Cantarero, A.; Garro, N.; Coraux, J.; Daudin, B.

    2007-10-15

    The strain state of GaN/AlN quantum dots grown on 6H-SiC has been investigated as a function of AlN capping thickness by three different techniques. On the one hand, resonant Raman scattering allowed the detection of the A{sub 1}(LO) quasiconfined mode. It was found that its frequency increases with AlN deposition, while its linewidth did not evolve significantly. Available experiments of multiwavelength anomalous diffraction and diffraction anomalous fine structure on the same samples provided the determination of the wurtzite lattice parameters a and c of the quantum dots. A very good agreement is found between resonant Raman scattering and x-ray measurements, especially concerning the in-plane strain state. The results demonstrate the adequacy of Raman scattering, in combination with the deformation potential and biaxial approximations, to determine quantitatively values of strain in GaN quantum dot layers.

  14. Spin-phonon and magnetostriction phenomena in CaMn{sub 7}O{sub 12} helimagnet probed by Raman spectroscopy

    SciTech Connect (OSTI)

    Nonato, A.; Araujo, B. S.; Ayala, A. P.; Maciel, A. P.; Yanez-Vilar, S.; Sanchez-Andujar, M.; Senaris-Rodriguez, M. A.; Paschoal, C. W. A.

    2014-12-01

    In this letter, we investigated the temperature-dependent Raman spectra of CaMn{sub 7}O{sub 12} helimagnet from room temperature down to 10?K. The temperature dependence of the Raman mode parameters shows remarkable anomalies for both antiferromagnetic and incommensurate transitions that this compound undergoes at low temperatures. The anomalies observed at the magnetic ordering transition indicate a spin-phonon coupling at higher-temperature magnetic transition in this material, while a magnetostriction effect at the lower-temperature magnetic transition.

  15. Raman spectral studies of aqueous zinc bromide solutions to 300/sup 0/C at pressures of 9 MPa

    SciTech Connect (OSTI)

    Yang, M.M.; Crerar, D.A.; Irish, D.E.

    1988-08-01

    A Raman spectral study of 14 solutions of varying bromide to zinc ratios was conducted up to 300/sup 0/C and 9 MPa. The tetra-, tri-, di- as well as the mono-bromozinc complexes were identified. The signal from the ZnBr/sup +/ complex increased in intensity as temperature increased, for solutions of low bromide- to-zinc ratios. The ZnBr/sub 4//sup 2 -/ species was favored at higher Br/Zn ratios, and higher temperatures favored the formation of the species ZnBr/sub 2/ and ZnBr/sup +/ at the expense of ZnBr/sub 4//sup 2 -/ and ZnBr/sub 3//sup -/. Although solvated water is probably present in these zinc-bromo complexes, they found no evidence of O-Zn vibrations other than for Zn(H/sub 2/O)/sub 6//sup 2 +/. However, spectra of successive dilutions of solutions with high bromide to zinc ratios show a relative change in species populations thereby suggesting that water activity plays a decisive role in complex formation. For the first time trifluoromethanesulfonic acid (HTFMS) has been used as an internal standard in Raman spectroscopy. This permitted quantitative measurement of stepwise stability constants.

  16. Rotational coherent anti-Stokes Raman spectroscopy (CARS) applied to thermometry in high-pressure hydrocarbon flames

    SciTech Connect (OSTI)

    Vestin, Fredrik; Sedarsky, David; Collin, Robert; Alden, Marcus; Linne, Mark; Bengtsson, Per-Erik

    2008-07-15

    Dual-broadband rotational coherent anti-Stokes Raman spectroscopy (DB-RCARS) has been investigated for thermometry under high-pressure and high-temperature conditions, in the product gas of fuel-lean hydrocarbon flames up to 1 MPa. Initial calibration measurements made in nitrogen, oxygen, and air, at pressures up to 1.55 MPa and temperatures up to 1800 K, showed good agreement between experimental and theoretical spectra. In the high-pressure flames, high-quality single-shot spectra were recorded in which nitrogen lines dominated, and peaks from CO{sub 2} and O{sub 2} were also visible. A spectral model including the species N{sub 2}, CO{sub 2}, and O{sub 2}, as well as the best available Raman linewidth models for flame thermometry, were used to evaluate the experimental spectra. Experimental problems as well as considerations related to the spectral evaluation are discussed. This work demonstrates the significant potential of DB-RCARS thermometry for applications in high-pressure and high-temperature environments. (author)

  17. Elastic properties, sp³ fraction, and Raman scattering in low and high pressure synthesized diamond-like boron rich carbides

    SciTech Connect (OSTI)

    Zinin, Pavel V.; Burgess, Katherine; Jia, Ruth; Sharma, Shiv; Ming, Li-Chung; Liu, Yongsheng; Ciston, Jim; Hong, Shiming

    2014-10-07

    Dense BC{sub x} phases with high boron concentration are predicted to be metastable, superhard, and conductors or superconductors depending on boron concentration. However, up to this point, diamond-like boron rich carbides BC{sub x} (dl-BC{sub x}) phases have been thought obtainable only through high pressure and high temperature treatment, necessitating small specimen volume. Here, we use electron energy loss spectroscopy combined with transmission electron microscopy, Raman spectroscopy, surface Brillouin scattering, laser ultrasonics (LU) technique, and analysis of elastic properties to demonstrate that low pressure synthesis (chemical vapor deposition) of BC{sub x} phases may also lead to the creation of diamond-like boron rich carbides. The elastic properties of the dl-BC{sub x} phases depend on the carbon sp²versus sp³ content, which decreases with increasing boron concentration, while the boron bonds determine the shape of the Raman spectra of the dl-BC{sub x} after high pressure-high temperature treatment. Using the estimation of the density value based on the sp³ fraction, the shear modulus ? of dl-BC?, containing 10% carbon atoms with sp³ bonds, and dl-B?C?, containing 38% carbon atoms with sp³ bonds, were found to be ? = 19.3 GPa and ? = 170 GPa, respectively. The presented experimental data also imply that boron atoms lead to a creation of sp³ bonds during the deposition processes.

  18. A new combined nuclear magnetic resonance and Raman spectroscopic probe applied to in situ investigations of catalysts and catalytic processes

    SciTech Connect (OSTI)

    Camp, Jules C. J.; Mantle, Michael D.; York, Andrew P. E.; McGregor, James

    2014-06-15

    Both Raman and nuclear magnetic resonance (NMR) spectroscopies are valuable analytical techniques capable of providing mechanistic information and thereby providing insights into chemical processes, including catalytic reactions. Since both techniques are chemically sensitive, they yield not only structural information but also quantitative analysis. In this work, for the first time, the combination of the two techniques in a single experimental apparatus is reported. This entailed the design of a new experimental probe capable of recording simultaneous measurements on the same sample and/or system of interest. The individual datasets acquired by each spectroscopic method are compared to their unmodified, stand-alone equivalents on a single sample as a means to benchmark this novel piece of equipment. The application towards monitoring reaction progress is demonstrated through the evolution of the homogeneous catalysed metathesis of 1?hexene, with both experimental techniques able to detect reactant consumption and product evolution. This is extended by inclusion of magic angle spinning (MAS) NMR capabilities with a custom made MAS 7 mm rotor capable of spinning speeds up to 1600 Hz, quantified by analysis of the spinning sidebands of a sample of KBr. The value of this is demonstrated through an application involving heterogeneous catalysis, namely the metathesis of 2-pentene and ethene. This provides the added benefit of being able to monitor both the reaction progress (by NMR spectroscopy) and also the structure of the catalyst (by Raman spectroscopy) on the very same sample, facilitating the development of structure-performance relationships.

  19. Synthesis of silver particles on copper substrates using ethanol-based solution for surface-enhanced Raman spectroscopy

    SciTech Connect (OSTI)

    Chen, Li Zhang, Zuojun; Chen, Gang; Zhou, Hui; Lai, Chunhong; School of Physics and Electronic Information, China West Normal University, NanChong 637002

    2014-03-15

    The displacement reaction of AgNO{sub 3} and copper metal is an effective and economical way to fabricate Ag-Cu surface enhanced Raman scattering (SERS) substrates. Aqueous solutions of AgNO{sub 3} are usually used for substrate preparation. In this work, a new method for Ag-Cu SERS substrate preparation is proposed, which uses an ethanol solution rather than an aqueous AgNO{sub 3} solution. Analysis of the surface morphologies of sample substrates by field emission scanning electron microscopy (FESEM) showed that the silver nanoparticles prepared by this new method were more regular than those prepared in the traditional aqueous solution. The SERS spectra of Rhodamine 6G (R6G) adsorbed on these Ag-Cu substrates were then investigated and compared. It was found that the Ag-Cu substrates prepared by this method provide significant improvements in Raman signal sensitivity and large-area uniformity. The enhancement factor of this new substrate is about 330 times higher than that prepared using an aqueous AgNO{sub 3} solution under identical experimental conditions. It was also found that 70% of the original sensitivity of the substrate remains after 15 days of exposure to air.

  20. Coherent Raman spectroscopy of A. Rubano,1 D. Paparo,2 F. Miletto Granozio,2 U. Scotti di Uccio,2,3

    E-Print Network [OSTI]

    Marrucci, Lorenzo

    ­667 (2000). 5. D. S. Chemla and J. Shah, "Many-body and correlation effects in semiconductors," Nature 411 Raman spectroscopy of high-temperature superconductors," in Handbook of vibrational spectroscopy, J. M in semiconductors," J. Appl. Phys. 70, 4317­4321 (1991). 15. B. Fainberg, "Laser-induced grating spectroscopy

  1. Symmetry Analysis for Tetrahedrane Tetrahedrane, C4H4, belongs to the Td point group. Use group theory to predict the number of IR and Raman

    E-Print Network [OSTI]

    Rioux, Frank

    Symmetry Analysis for Tetrahedrane Tetrahedrane, C4H4, belongs to the Td point group. Use group have three IR active modes (3T2) and seven Raman active modes (2A1 + 2E + 3T2). Two of the IR modes

  2. Soret Effect Study on High-Pressure CO2-Water Solutions Using UV-Raman Spectroscopy and a Concentric-Tube Optical Cell

    SciTech Connect (OSTI)

    Windisch, Charles F.; McGrail, B. Peter; Maupin, Gary D.

    2012-01-01

    Spatially resolved deep-UV Raman spectroscopy was applied to solutions of CO2 and H2O (or D2O), which were subject to a temperature gradient in a thermally regulated high-pressure concentric-tube Raman cell in an attempt to measure a Soret effect in the vicinity of the critical point of CO2. Although Raman spectra of solutions of CO2 dissolved in D2O at 10 MPa and temperatures near the critical point of CO2 had adequate signal-to-noise and spatial resolution to observe a Soret effect with a Soret coefficient with magnitude of |ST| > 0.03, no evidence for an effect of this size was obtained for applied temperature gradients up to 19oC. The presence of 1 M NaCl did not make a difference. In contrast, the concentration of CO2 dissolved in H2O was shown to vary significantly across the temperature gradient when excess CO2 was present, but the results could be explained simply by the variation in CO2 solubility over the temperature range and not to kinetic factors. For mixtures of D2O dissolved in scCO2 at 10 MPa and temperatures close to the critical point of CO2, the Raman peaks for H2O were too weak to measure with confidence even at the limit of D2O solubility.

  3. Inner-Shell Excitation Spectroscopy of Fused-Ring Aromatic Molecules by Electron Energy Loss and X-ray Raman Techniques

    E-Print Network [OSTI]

    Hitchcock, Adam P.

    recorded under scattering conditions where electric dipole transitions dominate (2.5 keV residual energy.08). These spectra are interpreted with the aid of ab initio calculations on selected species. They are compared,2-benzanthracene, recorded with inelastic X-ray Raman scattering in the dipole limit (qr

  4. Micro- and nanodomain imaging in uniaxial ferroelectrics: Joint application of optical, confocal Raman, and piezoelectric force microscopy

    SciTech Connect (OSTI)

    Shur, V. Ya., E-mail: vladimir.shur@urfu.ru; Zelenovskiy, P. S. [Ferroelectric Laboratory, Institute of Natural Sciences, Ural Federal University, 620000 Ekaterinburg (Russian Federation)

    2014-08-14

    The application of the most effective methods of the domain visualization in model uniaxial ferroelectrics of lithium niobate (LN) and lithium tantalate (LT) family, and relaxor strontium-barium niobate (SBN) have been reviewed in this paper. We have demonstrated the synergetic effect of joint usage of optical, confocal Raman, and piezoelectric force microscopies which provide extracting of the unique information about formation of the micro- and nanodomain structures. The methods have been applied for investigation of various types of domain structures with increasing complexity: (1) periodical domain structure in LN and LT, (2) nanodomain structures in LN, LT, and SBN, (3) nanodomain structures in LN with modified surface layer, (4) dendrite domain structure in LN. The self-assembled appearance of quasi-regular nanodomain structures in highly non-equilibrium switching conditions has been considered.

  5. Theoretical approach for optical response in electrochemical systems: Application to electrode potential dependence of surface-enhanced Raman scattering

    SciTech Connect (OSTI)

    Iida, Kenji; Noda, Masashi; Nobusada, Katsuyuki, E-mail: nobusada@ims.ac.jp [Department of Theoretical and Computational Molecular Science, Institute for Molecular Science, Okazaki 444-8585 (Japan)

    2014-09-28

    We propose a theoretical approach for optical response in electrochemical systems. The fundamental equation to be solved is based on a time-dependent density functional theory in real-time and real-space in combination with its finite temperature formula treating an electrode potential. Solvation effects are evaluated by a dielectric continuum theory. The approach allows us to treat optical response in electrochemical systems at the atomistic level of theory. We have applied the method to surface-enhanced Raman scattering (SERS) of 4-mercaptopyridine on an Ag electrode surface. It is shown that the SERS intensity has a peak as a function of the electrode potential. Furthermore, the real-space computational approach facilitates visualization of variation of the SERS intensity depending on an electrode potential.

  6. Two-beam ultrabroadband coherent anti-Stokes Raman spectroscopy for high resolution gas-phase multiplex imaging

    SciTech Connect (OSTI)

    Bohlin, Alexis; Kliewer, Christopher J.

    2014-01-20

    We propose and develop a method for wideband coherent anti-Stokes Raman spectroscopy (CARS) in the gas phase and demonstrate the single-shot measurement of N{sub 2}, H{sub 2}, CO{sub 2}, O{sub 2}, and CH{sub 4}. Pure-rotational and vibrational O-, Q-, and S- branch spectra are collected simultaneously, with high spectral and spatial resolution, and within a single-laser-shot. The relative intensity of the rotational and vibrational signals can be tuned arbitrarily using polarization techniques. The ultrashort 7 fs pump and Stokes pulses are automatically overlapped temporally and spatially using a two-beam CARS technique, and the crossed probe beam allows for excellent spatial sectioning of the probed location.

  7. Cost effective nanostructured copper substrates prepared with ultrafast laser pulses for explosives detection using surface enhanced Raman scattering

    SciTech Connect (OSTI)

    Hamad, Syed; Podagatlapalli, G. Krishna; Soma, Venugopal Rao E-mail: soma-venu@yahoo.com; Mohiddon, Md. Ahamad

    2014-06-30

    Ultrafast laser pulses induced surface nanostructures were fabricated on a copper (Cu) target through ablation in acetone, dichloromethane, acetonitrile, and chloroform. Surface morphological information accomplished from the field emission scanning electron microscopic data demonstrated the diversities of ablation mechanism in each case. Fabricated Cu substrates were utilized exultantly to investigate the surface plasmon (localized and propagating) mediated enhancements of different analytes using surface enhance Raman scattering (SERS) studies. Multiple utility of these substrates were efficiently demonstrated by collecting the SERS data of Rhodamine 6G molecule and two different secondary explosive molecules such as 5-amino-3-nitro-l,2,4-triazole and trinitrotoluene on different days which were weeks apart. We achieved significant enhancement factors of >10{sup 5} through an easily adoptable cleaning procedure.

  8. Raman laser with intracavity conversion of 1.34-?m laser radiation in a BaWO{sub 4} crystal

    SciTech Connect (OSTI)

    Gavrilov, A V; Ershkov, M N; Fedin, A V [V.A. Degtyarev Kovrov State Technological Academy, Kovrov, Vladimir region (Russian Federation)

    2013-12-31

    Intracavity Raman conversion of 1.34-?m radiation of a Nd : YAG laser by a BaWO{sub 4} crystal into the 1.53-?m first-Stokes component is studied in different operation regimes. In the case of passive Q-switching of the Nd : YAG laser, the SRS radiation has an average power of 0.28 W with a pulse train energy up to 5 mJ, an individual pulse duration of 19 ns, and a pump pulse repetition rate of 15 Hz. In the case of active Q-switching, the average SRS power is 0.85 W at a pulse energy up to 28 mJ, a pulse duration of 20 ns, and a pump pulse repetition rate of 30 Hz. (lasers)

  9. Book Review: Reiner Salzer and Heinz W. Siesler (Eds.): Infrared and Raman spectroscopic imaging, 2nd ed.

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Moore, David Steven

    2015-05-10

    This second edition of "Infrared and Raman Spectroscopic Imaging" propels practitioners in that wide-ranging field, as well as other readers, to the current state of the art in a well-produced and full-color, completely revised and updated, volume. This new edition chronicles the expanded application of vibrational spectroscopic imaging from yesterday's time-consuming point-by-point buildup of a hyperspectral image cube, through the improvements afforded by the addition of focal plane arrays and line scan imaging, to methods applicable beyond the diffraction limit, instructs the reader on the improved instrumentation and image and data analysis methods, and expounds on their application to fundamentalmore »biomedical knowledge, food and agricultural surveys, materials science, process and quality control, and many others.« less

  10. Development of a Raman spectroscopy technique to detect alternate transportation fuel hydrocarbon intermediates in complex combustion environments.

    SciTech Connect (OSTI)

    Ekoto, Isaac W.; Barlow, Robert S.

    2012-12-01

    Spontaneous Raman spectra for important hydrocarbon fuels and combustion intermediates were recorded over a range of low-to-moderate flame temperatures using the multiscalar measurement facility located at Sandia/CA. Recorded spectra were extrapolated to higher flame temperatures and then converted into empirical spectral libraries that can readily be incorporated into existing post-processing analysis models that account for crosstalk from overlapping hydrocarbon channel signal. Performance testing of the developed libraries and reduction methods was conducted through an examination of results from well-characterized laminar reference flames, and was found to provide good agreement. The diagnostic development allows for temporally and spatially resolved flame measurements of speciated hydrocarbon concentrations whose parent is more chemically complex than methane. Such data are needed to validate increasingly complex flame simulations.

  11. Co-localised Raman and force spectroscopy reveal the roles of hydrogen bonds and ?-? interactions in defining the mechanical properties of diphenylalanine nano- and micro-tubes

    SciTech Connect (OSTI)

    Sinjab, Faris; Bondakov, Georgi; Notingher, Ioan, E-mail: ioan.notingher@nottingham.ac.uk [School of Physics and Astronomy, University of Nottingham, Nottingham (United Kingdom)

    2014-06-23

    An integrated atomic force and polarized Raman microscope were used to measure the elastic properties of individual diphenylalanine (FF) nano- and micro-tubes and to obtain quantitative information regarding the inter-molecular interactions that define their mechanical properties. For individual tubes, co-localised force spectroscopy and Raman spectroscopy measurements allowed the calculation of the Young's and shear moduli (25?±?5?GPa and 0.28?±?0.05?GPa, respectively) and the contribution of hydrogen bonding network to the Young's modulus (?17.6?GPa). The ?-? interactions between the phenyl rings, dominated by T-type arrangements, were estimated based on previously published X-ray data to only 0.20?GPa. These results provide experimental evidence obtained from individual FF tubes that the network of H-bonds dominates the elastic properties of the FF tubes.

  12. Enhancement of Raman Light Scattering in Dye-Labeled Rat Glioma Cells by Langmuir-Blodgett CNT-Bundles Arranged on Metal-Containing Conducting Polymer Film

    E-Print Network [OSTI]

    Egorov, A S; Grushevskaya, H V; Krot, V I; Krylova, N G; Lipnevich, I V; Orekhovskaya, T I; Shulitsky, B G

    2015-01-01

    We have fabricated layered nanocomposite consisting of a nanoporous anodic alumina sublayer (AOA), an ultrathin metal-containing polymer Langmuir-Blodgett (LB) film coating AOA, and multi-walled carbon nanotube (MCNT) - bundles which are arranged on the LB-film. MCNTs were preliminarily chemically modified by carboxyl groups and functionalized by stearic acid. We have experimentally observed an enhancement of Raman light scattering on surface plasmons in the LB-monolayers. This enhancement is due to charge and energy transfer. We demonstrate that propidium iodide (PI) fluorescence is quenched by the MCNT-bundles. A method of two-dimensional system imaging based on the MCNT-enhanced Raman spectroscopy has been proposed. This method has been applied to visualize focal adhesion sites on membranes of living PI-labeled rat glioma cells.

  13. Raman Spectroscopy of the Reaction of Thin Films of Solid-State Benzene with Vapor-Deposited Ag, Mg, and Al

    SciTech Connect (OSTI)

    Schalnat, Matthew C.; Hawkridge, Adam M.; Pemberton, Jeanne E.

    2011-07-21

    Thin films of solid-state benzene at 30 K were reacted with small quantities of vapor-deposited Ag, Mg, and Al under ultrahigh vacuum, and products were monitored using surface Raman spectroscopy. Although Ag and Mg produce small amounts of metal–benzene adduct products, the resulting Raman spectra are dominated by surface enhancement of the normal benzene modes from metallic nanoparticles suggesting rapid Ag or Mg metallization of the film. In contrast, large quantities of Al adduct products are observed. Vibrational modes of the products in all three systems suggest adducts that are formed through a pathway initiated by an electron transfer reaction. The difference in reactivity between these metals is ascribed to differences in ionization potential of the metal atoms; ionization potential values for Ag and Mg are similar but larger than that for Al. These studies demonstrate the importance of atomic parameters, such as ionization potential, in solid-state metal–organic reaction chemistry.

  14. Development of an Integrated Raman and Turbidity Fiber Optic Sensor for the In-Situ Analysis of High Level Nuclear Waste

    SciTech Connect (OSTI)

    Gasbarro, Christina; Bello, Job M.; Bryan, Samuel A.; Lines, Amanda M.; Levitskaia, Tatiana G.

    2013-02-24

    Stored nuclear waste must be retrieved from storage, treated, separated into low- and high-level waste streams, and finally put into a disposal form that effectively encapsulates the waste and isolates it from the environment for a long period of time. Before waste retrieval can be done, waste composition needs to be characterized so that proper safety precautions can be implemented during the retrieval process. In addition, there is a need for active monitoring of the dynamic chemistry of the waste during storage since the waste composition can become highly corrosive. This work describes the development of a novel, integrated fiber optic Raman and light scattering probe for in situ use in nuclear waste solutions. The dual Raman and turbidity sensor provides simultaneous chemical identification of nuclear waste as well as information concerning the suspended particles in the waste using a common laser excitation source.

  15. Development of an Integrated Raman and Turbidity Fiber Optic Sensor for the In-Situ Analysis of High Level Nuclear Waste - 13532

    SciTech Connect (OSTI)

    Gasbarro, Christina; Bello, Job [EIC Laboratories, Inc., 111 Downey St., Norwood, MA, 02062 (United States)] [EIC Laboratories, Inc., 111 Downey St., Norwood, MA, 02062 (United States); Bryan, Samuel; Lines, Amanda; Levitskaia, Tatiana [Pacific Northwest National Laboratory, PO Box 999, Richland, WA, 99352 (United States)] [Pacific Northwest National Laboratory, PO Box 999, Richland, WA, 99352 (United States)

    2013-07-01

    Stored nuclear waste must be retrieved from storage, treated, separated into low- and high-level waste streams, and finally put into a disposal form that effectively encapsulates the waste and isolates it from the environment for a long period of time. Before waste retrieval can be done, waste composition needs to be characterized so that proper safety precautions can be implemented during the retrieval process. In addition, there is a need for active monitoring of the dynamic chemistry of the waste during storage since the waste composition can become highly corrosive. This work describes the development of a novel, integrated fiber optic Raman and light scattering probe for in situ use in nuclear waste solutions. The dual Raman and turbidity sensor provides simultaneous chemical identification of nuclear waste as well as information concerning the suspended particles in the waste using a common laser excitation source. (authors)

  16. Micro-Raman study on the softening and stiffening of phonons in rutile titanium dioxide film: Competing effects of structural defects, crystallite size, and lattice strain

    SciTech Connect (OSTI)

    Gautam, Subodh K.; Singh, Fouran, E-mail: fouran@gmail.com; Sulania, I.; Kulriya, P. K. [Materials Science Group, Inter University Accelerator Centre, Aruna Asaf Ali Marg, New Delhi 110067 (India); Singh, R. G. [Department of Physics, Bhagini Nivedita College, Delhi University, Delhi 110043 (India); Pippel, E. [Max Planck Institute of Microstructure Physics, Weinberg 2, D-06120 Halle (Germany)

    2014-04-14

    Softening and stiffening of phonons in rutile titanium dioxide films are investigated by in situ micro-Raman studies during energetic ion irradiation. The in situ study minimized other possible mechanisms of phonon dynamics. Initial softening and broadening of Raman shift are attributed to the phonon confinement by structural defects and loss of stoichiometry. The stiffening of A{sub 1g} mode is ascribed to large distortion of TiO{sub 6} octahedra under the influence of lattice strain in the (110) plane, which gives rise to lengthening of equatorial Ti-O bond and shortening of apical Ti-O bond. The shortening of apical Ti-O bond induces stiffening of A{sub 1g} mode in the framework of the bond-order-length-strength correlation mechanism.

  17. Lattice parameters and Raman-active phonon modes of (In{sub x}Ga{sub 1–x})?O? for x<0.4

    SciTech Connect (OSTI)

    Kranert, Christian Lenzner, Jörg; Jenderka, Marcus; Lorenz, Michael; Wenckstern, Holger von; Schmidt-Grund, Rüdiger; Grundmann, Marius

    2014-07-07

    We present X-ray diffraction and Raman spectroscopy investigations of (In{sub x}Ga{sub 1–x})?O? thin films and bulk-like ceramics in dependence of their composition. The thin films grown by pulsed laser deposition have a continuous lateral composition spread allowing the determination of phonon mode properties and lattice parameters with high sensitivity to the composition from a single 2-in. wafer. In the regime of low indium concentration, the phonon energies depend linearly on the composition and show a good agreement between both sample types. We determined the slopes of these dependencies for eight different Raman modes. While the lattice parameters of the ceramics follow Vegard's rule, deviations are observed for the thin films. Further, we found indications of the high-pressure phase InGaO? II in the thin films above a critical indium concentration, its value depending on the type of substrate.

  18. Plasmon Mapping in Metallic Nanostructures and its Application to Single Molecule Surface Enhanced Raman Scattering: Imaging Electromagnetic Hot-Spots and Analyte Location

    SciTech Connect (OSTI)

    Camden, Jon P

    2013-07-16

    A major component of this proposal is to elucidate the connection between optical and electron excitation of plasmon modes in metallic nanostructures. These accomplishments are reported: developed a routine protocol for obtaining spatially resolved, low energy EELS spectra, and resonance Rayleigh scattering spectra from the same nanostructures.; correlated optical scattering spectra and plasmon maps obtained using STEM/EELS.; and imaged electromagnetic hot spots responsible for single-molecule surface-enhanced Raman scattering (SMSERS).

  19. Comparison of Mixed Layer Heights from Airborne High Spectral Resolution Lidar, Ground-based Measurements, and the WRP-Chem Model during CalNex and CARES

    SciTech Connect (OSTI)

    Scarino, Amy Jo; Obland, Michael; Fast, Jerome D.; Burton, S. P.; Ferrare, R. A.; Hostetler, Chris A.; Berg, Larry K.; Lefer, Barry; Haman, C.; Hair, John; Rogers, Ray; Butler, Carolyn; Cook, A. L.; Harper, David

    2014-06-05

    The California Research at the Nexus of Air Quality and Climate Change (CalNex) and Carbonaceous Aerosol and Radiative Effects Study (CARES) field campaigns during May and June 2010 provided a data set appropriate for studying characteristics of the planetary boundary layer (PBL). The NASA Langley Research Center (LaRC) airborne High Spectral Resolution Lidar (HSRL) was deployed to California onboard the NASA LaRC B-200 aircraft to aid incharacterizing aerosol properties during these two field campaigns. Measurements of aerosol extinction (532 nm), backscatter (532 and 1064 nm), and depolarization (532 and 1064 nm) profiles during 31 flights, many in coordination with other research aircraft and ground sites, constitute a diverse data set for use in characterizing the spatial and temporal distribution of aerosols, as well as the depth and variability of the daytime mixed layer (ML), which is a subset within the PBL. This work illustrates the temporal and spatial variability of the ML in the vicinity of Los Angeles and Sacramento, CA. ML heights derived from HSRL measurements are compared to PBL heights derived from radiosonde profiles, ML heights measured from ceilometers, and simulated PBL heights from the Weather Research and Forecasting Chemistry (WRF-Chem) community model. Comparisons between the HSRL ML heights and the radiosonde profiles in Sacramento result in a correlation coefficient value (R) of 0.93 (root7 mean-square (RMS) difference of 157 m and bias difference (HSRL radiosonde) of 5 m). HSRL ML heights compare well with those from the ceilometer in the LA Basin with an R of 0.89 (RMS difference of 108 m and bias difference (HSRL Ceilometer) of -9.7 m) for distances of up to 30 km between the B-200 flight track and the ceilometer site. Simulated PBL heights from WRF-Chem were compared with those obtained from all flights for each campaign, producing an R of 0.58 (RMS difference of 604 m and a bias difference (WRF-Chem HSRL) of -157 m) for CalNex and 0.59 (RMS difference of 689 m and a bias difference (WRF-Chem HSRL) of 220 m) for CARES. Aerosol backscatter simulations are also available from WRF15 Chem and are compared to those from HSRL to examine differences among the methods used to derive ML heights.

  20. New topics in coherent anti-stokes raman scattering gas-phase diagnostics : femtosecond rotational CARS and electric-field measurements.

    SciTech Connect (OSTI)

    Lempert, Walter R.; Barnat, Edward V.; Kearney, Sean Patrick; Serrano, Justin Raymond

    2010-07-01

    We discuss two recent diagnostic-development efforts in our laboratory: femtosecond pure-rotational Coherent anti-Stokes Raman scattering (CARS) for thermometry and species detection in nitrogen and air, and nanosecond vibrational CARS measurements of electric fields in air. Transient pure-rotational fs-CARS data show the evolution of the rotational Raman polarization in nitrogen and air over the first 20 ps after impulsive pump/Stokes excitation. The Raman-resonant signal strength at long time delays is large, and we additionally observe large time separation between the fs-CARS signatures of nitrogen and oxygen, so that the pure-rotational approach to fs-CARS has promise for simultaneous species and temperature measurements with suppressed nonresonant background. Nanosecond vibrational CARS of nitrogen for electric-field measurements is also demonstrated. In the presence of an electric field, a dipole is induced in the otherwise nonpolar nitrogen molecule, which can be probed with the introduction of strong collinear pump and Stokes fields, resulting in CARS signal radiation in the infrared. The electric-field diagnostic is demonstrated in air, where the strength of the coherent infrared emission and sensitivity our field measurements is quantified, and the scaling of the infrared signal with field strength is verified.

  1. Complete characterization by Raman spectroscopy of the structural properties of thin hydrogenated diamond-like carbon films exposed to rapid thermal annealing

    SciTech Connect (OSTI)

    Rose, Franck Wang, Na; Smith, Robert; Xiao, Qi-Fan; Dai, Qing; Marchon, Bruno; Inaba, Hiroshi; Matsumura, Toru; Saito, Yoko; Matsumoto, Hiroyuki; Mangolini, Filippo; Carpick, Robert W.

    2014-09-28

    We have demonstrated that multi-wavelength Raman and photoluminescence spectroscopies are sufficient to completely characterize the structural properties of ultra-thin hydrogenated diamond-like carbon (DLC:H) films subjected to rapid thermal annealing (RTA, 1 s up to 659 °C) and to resolve the structural differences between films grown by plasma-enhanced chemical vapor deposition, facing target sputtering and filtered cathodic vacuum arc with minute variations in values of mass density, hydrogen content, and sp³ fraction. In order to distinguish unequivocally between films prepared with different density, thickness, and RTA treatment, a new method for analysis of Raman spectra was invented. This newly developed analysis method consisted of plotting the position of the Raman G band of carbon versus its full width at half maximum. Moreover, we studied the passivation of non-radiative recombination centers during RTA by performing measurements of the increase in photoluminescence in conjunction with the analysis of DLC:H networks simulated by molecular dynamics. The results show that dangling bond passivation is primarily a consequence of thermally-induced sp² clustering rather than hydrogen diffusion in the film.

  2. Diffraction barrier breakthrough in coherent anti-Stokes Raman scattering microscopy by additional probe-beam-induced phonon depletion

    SciTech Connect (OSTI)

    Liu Wei; Niu Hanben

    2011-02-15

    We provide an approach to significantly break the diffraction limit in coherent anti-Stokes Raman scattering (CARS) microscopy via an additional probe-beam-induced photon depletion (APIPD). The additional probe beam, whose profile is doughnut shaped and whose wavelength is different from the Gaussian probe beam, depletes the phonons to yield an unwanted anti-Stokes signal within a certain bandwidth at the rim of the diffraction-limited spot. When the Gaussian probe beam that follows immediately arrives, no anti-Stokes signal is generated in this region, resembling stimulated emission depletion (STED) microscopy, and the spot-generating useful anti-Stokes signals by this beam are substantially suppressed to a much smaller dimension. Scanning the spot renders three-dimensional, label-free, and chemically selective CARS images with subdiffraction resolution. Also, resolution-enhanced images of the molecule, specified by its broadband even-total CARS spectral signals not only by one anti-Stokes signal for its special chemical bond, can be obtained by employing a supercontinuum source.

  3. Effects of phase and coupling between the vibrational modes on selective excitation in coherent anti-Stokes Raman scattering microscopy

    SciTech Connect (OSTI)

    Patel, Vishesha; Malinovsky, Vladimir S.; Malinovskaya, Svetlana

    2010-06-15

    Coherent anti-Stokes Raman scattering (CARS) microscopy has been a major tool of investigation of biological structures as it contains the vibrational signature of molecules. A quantum control method based on chirped pulse adiabatic passage was recently proposed for selective excitation of a predetermined vibrational mode in CARS microscopy [Malinovskaya and Malinovsky, Opt. Lett. 32, 707 (2007)]. The method utilizes the chirp sign variation at the peak pulse amplitude and gives a robust adiabatic excitation of the desired vibrational mode. Using this method, we investigate the impact of coupling between vibrational modes in molecules on controllability of excitation of the CARS signal. We analyze two models of two coupled two-level systems (TLSs) having slightly different transitional frequencies. The first model, featuring degenerate ground states of the TLSs, gives robust adiabatic excitation and maximum coherence in the resonant TLS for positive value of the chirp. In the second model, implying nondegenerate ground states in the TLSs, a population distribution is observed in both TLSs, resulting in a lack of selectivity of excitation and low coherence. It is shown that the relative phase and coupling between the TLSs play an important role in optimizing coherence in the desired vibrational mode and suppressing unwanted transitions in CARS microscopy.

  4. Multimode Raman light-atom interface in warm atomic ensemble as multiple three-mode quantum operations

    E-Print Network [OSTI]

    Micha? Parniak; Daniel P?cak; Wojciech Wasilewski

    2015-06-29

    We analyze the properties of a Raman quantum light-atom interface in long atomic ensemble and its applications as a quantum memory or two-mode squeezed state generator. We consider the weak-coupling regime and include both Stokes and anti-Stokes scattering and the effects of Doppler broadening in buffer gas assuming frequent velocity-averaging collisions. We find the Green functions describing multimode transformation from input to output fields of photons and atomic excitations. Proper mode basis is found via singular value decomposition for short interaction times. It reveals that triples of modes are coupled by a transformation equivalent to a combination of two beamsplitters and a two-mode squeezing operation. We analyze the possible transformations on an example of warm rubidium-87 vapor. The model we present bridges the gap between the Stokes only and anti-Stokes only interactions providing simple, universal description in a temporally and longitudinally multimode situation. Our results also provide an easy way to find an evolution of the states in a Schr\\"odinger picture thus facilitating understanding and design.

  5. A statistical model approximation for perovskite solid-solutions: a Raman study of lead-zirconate- titanate single crystal

    SciTech Connect (OSTI)

    Frantti, Johannes [Aalto University, Finland; Fujioka, Y [Aalto University, Finland; Puretzky, Alexander A [ORNL; Xie, Y [Simon Fraser University, Canada; Glazer, A [Clarendon Laboratory, Department of Physics, University of Oxford

    2013-01-01

    Lead titanate (PbTiO3) is a classical example of a ferroelectric perovskite oxide illustrating a displacive phase transition accompanied by a softening of a symmetry-breaking mode. The underlying assumption justifying the soft-mode theory is that the crystal is macroscopically sufficiently uniform so that a meaningful free energy function can be formed. In contrast to PbTiO3, experimental studies show that the phase transition behaviour of lead-zirconate-titanate solid solution (PZT) is far more subtle. Most of the studies on the PZT system have been dedicated to ceramic or powder samples, in which case an unambiguous soft-mode study is not possible, as modes with different symmetries appear together. Our Raman scattering study on titanium-rich PZT single crystal shows that the phase transitions in PZT cannot be described by a simple soft-mode theory. In strong contrast to PbTiO3, splitting of transverse E-symmetry modes reveals that there are different locally-ordered regions. The role of crystal defects, random distribution of Ti and Zr at the B- cation site and Pb ions shifted away from their ideal positions, dictates the phase transition mechanism. A statistical model explaining the observed peak splitting and phase transformation to a complex state with spatially varying local order in the vicinity of the morphotropic phase boundary is given.

  6. Formation of Raman Scattering Wings around H alpha, H beta and Pa alpha in Active Galactic Nuclei

    E-Print Network [OSTI]

    Chang, Seok-Jun; Di Mille, Francesco; Angeloni, Rodolfo; Palma, Tali; Lee, Hee-Won

    2015-01-01

    Powered by a supermassive black hole with an accretion disk, the spectra of active galactic nuclei (AGNs) are characterized by prominent emission lines including Balmer lines. The unification schemes of AGNs require the existence of a thick molecular torus that may hide the broad emission line region from the view of observers near the equatorial direction. In this configuration, one may expect that the far UV radiation from the central engine can be Raman scattered by neutral hydrogen to reappear around Balmer and Paschen emission lines which can be identified with broad wings. We produce H$\\alpha$, H$\\beta$ and Pa$\\alpha$ wings using a Monte Carlo technique to investigate their properties. The neutral scattering region is assumed to be a cylindrical torus specified by the inner and outer radii and the height. While the covering factor of the scattering region affects the overall strengths of the wings, the wing widths are primarily dependent on the neutral hydrogen column density $N_{\\rm HI}$ being roughly ...

  7. In-situ laser Raman scattering and far infrared spectroscopy studies of corrosion-passivation phenomena in metals.

    SciTech Connect (OSTI)

    Melendres, C. A.

    1999-06-28

    Vibrational spectroscopic and electrochemical techniques are among the most useful tools for the elucidation of corrosion-passivation phenomena in metals. The former can provide information on the structure and composition of corrosion films ''in situ'' in aqueous solution environments, while thermodynamic and kinetic information may be obtained using electrochemical techniques. In this paper, we demonstrate the application of Laser Raman Scattering (LRS) and Synchrotrons Far Infrared Reflectance Spectroscopy (SFIRS), coupled with electrochemical methods, for the determination of the structure and composition of surface films on nickel and copper in aqueous solution environment. The corrosion film on nickel has been found to consist of NiO and Ni(OH){sub 2} in the passive region of potential and NiOOH in the transpassive region. The film on copper consists of Cu{sub 2}O, CUO and Cu(OH){sub 2}. We also show for the first time that SFIRS can be used to obtain information on the adsorption of ions on a metal surface with sub-monolayer sensitivity. Adsorption of Cl{sup {minus}}, Br{sup {minus}}, SO{sup {minus}2}, and PO{sub 4}{sup {minus}3} was found to occur at gold electrodes in perchloric acid solution. We also observed that when two different ions are present in solution, the more strongly adsorbed ion determined the corrosion behavior of the metal.

  8. Crystal structure of fluorite-related Ln{sub 3}SbO{sub 7} (Ln=La–Dy) ceramics studied by synchrotron X-ray diffraction and Raman scattering

    SciTech Connect (OSTI)

    Siqueira, K.P.F.; Borges, R.M.; Granado, E.; Malard, L.M.; Paula, A.M. de; Moreira, R.L.; Bittar, E.M.; Dias, A.

    2013-07-15

    Ln{sub 3}SbO{sub 7} (Ln=La, Pr, Nd, Sm, Eu, Gd, Tb and Dy) ceramics were synthesized by solid-state reaction in optimized conditions of temperature and time to yield single-phase ceramics. The crystal structures of the obtained ceramics were investigated by synchrotron X-ray diffraction, second harmonic generation (SHG) and Raman scattering. All samples exhibited fluorite-type orthorhombic structures with different oxygen arrangements as a function of the ionic radius of the lanthanide metal. For ceramics with the largest ionic radii (La–Nd), the ceramics crystallized into the Cmcm space group, while the ceramics with intermediate and smallest ionic radii (Sm–Dy) exhibited a different crystal structure belonging to the same space group, described under the Ccmm setting. The results from SHG and Raman scattering confirmed these settings and ruled out any possibility for the non-centrosymmetric C222{sub 1} space group describing the structure of the small ionic radii ceramics, solving a recent controversy in the literature. Besides, the Raman modes for all samples are reported for the first time, showing characteristic features for each group of samples. - Graphical abstract: Raman spectrum for La{sub 3}SbO{sub 7} ceramics showing their 22 phonon modes adjusted through Lorentzian lines. According to synchrotron X-ray diffraction and Raman scattering, this material belongs to the space group Cmcm. - Highlights: • Ln{sub 3}SbO{sub 7} ceramics belonging to the space groups Cmcm and Ccmm are synthesized. • SXRD, SHG and Raman scattering confirmed the orthorhombic structures. • Ccmm instead of C222{sub 1} is the correct one based on SHG and Raman data.

  9. Microtopographic characterization of ice-wedge polygon landscape in Barrow, Alaska: a digital map of troughs, rims, centers derived from high resolution (0.25 m) LiDAR data

    SciTech Connect (OSTI)

    Gangodagamage, Chandana; Wullschleger, Stan

    2014-07-03

    The dataset represents microtopographic characterization of the ice-wedge polygon landscape in Barrow, Alaska. Three microtopographic features are delineated using 0.25 m high resolution digital elevation dataset derived from LiDAR. The troughs, rims, and centers are the three categories in this classification scheme. The polygon troughs are the surface expression of the ice-wedges that are in lower elevations than the interior polygon. The elevated shoulders of the polygon interior immediately adjacent to the polygon troughs are the polygon rims for the low center polygons. In case of high center polygons, these features are the topographic highs. In this classification scheme, both topographic highs and rims are considered as polygon rims. The next version of the dataset will include more refined classification scheme including separate classes for rims ad topographic highs. The interior part of the polygon just adjacent to the polygon rims are the polygon centers.

  10. Microtopographic characterization of ice-wedge polygon landscape in Barrow, Alaska: a digital map of troughs, rims, centers derived from high resolution (0.25 m) LiDAR data

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Gangodagamage, Chandana; Wullschleger, Stan

    The dataset represents microtopographic characterization of the ice-wedge polygon landscape in Barrow, Alaska. Three microtopographic features are delineated using 0.25 m high resolution digital elevation dataset derived from LiDAR. The troughs, rims, and centers are the three categories in this classification scheme. The polygon troughs are the surface expression of the ice-wedges that are in lower elevations than the interior polygon. The elevated shoulders of the polygon interior immediately adjacent to the polygon troughs are the polygon rims for the low center polygons. In case of high center polygons, these features are the topographic highs. In this classification scheme, both topographic highs and rims are considered as polygon rims. The next version of the dataset will include more refined classification scheme including separate classes for rims ad topographic highs. The interior part of the polygon just adjacent to the polygon rims are the polygon centers.

  11. Effects of alloy disorder and confinement on phonon modes and Raman scattering in Si{sub x}Ge{sub 1?x} nanocrystals: A microscopic modeling

    SciTech Connect (OSTI)

    Vasin, A. S.; Vikhrova, O. V. [Department of Physics and NIFTI, N. I. Lobachevskii University of Nizhnii Novgorod, Nizhnii Novgorod 603600 (Russian Federation); Vasilevskiy, M. I., E-mail: mikhail@fisica.uminho.pt [Centro de Física, Universidade do Minho, Campus de Gualtar, 4710-057 Braga (Portugal)

    2014-04-14

    Confinement and alloy disorder effects on the lattice dynamics and Raman scattering in Si{sub 1?x}Ge{sub x} nanocrystals (NCs) are investigated numerically employing two different empirical inter-atomic potentials. Relaxed NCs of different compositions (x) were built using the Molecular Dynamics method and applying rigid boundary conditions mimicking the effect of surrounding matrix. The resulting variation of bond lengths with x was checked against Vegard's law and the NC phonon modes were calculated using the same inter-atomic potential. The localization of the principal Raman-active (Si-Si, Si-Ge, and Ge-Ge) modes is investigated by analysing representative eigenvectors and their inverse participation ratio. The dependence of the position and intensity of these modes upon x and NC size is presented and compared to previous calculated results and available experimental data. In particular, it is argued that the composition dependence of the intensity of the Si-Ge and Ge-Ge modes does not follow the fraction of the corresponding nearest-neighbour bonds as it was suggested by some authors. Possible effects of alloy segregation are considered by comparing the calculated properties of random and clustered Si{sub x}Ge{sub 1?x} NCs. It is found that the Si-Si mode and Ge-Ge mode are enhanced and blue-shifted (by several cm{sup ?1}for the Si-Si mode), while the intensity of the Si-Ge Raman mode is strongly suppressed by clustering.

  12. More light on the 2?{sub 5} Raman overtone of SF{sub 6}: Can a weak anisotropic spectrum be due to a strong transition anisotropy?

    SciTech Connect (OSTI)

    Kremer, D.; Rachet, F.; Chrysos, M., E-mail: michel.chrysos@univ-angers.fr [LUNAM Université, Université d’Angers, CNRS UMR 6200, Laboratoire MOLTECH-Anjou, 2 Bd Lavoisier, 49045 Angers (France)

    2014-01-21

    Long known as a fully polarized band with a near vanishing depolarization ratio [?{sub s} = 0.05, W. Holzer and R. Ouillon, Chem. Phys. Lett. 24, 589 (1974)], the 2?{sub 5} Raman overtone of SF{sub 6} has so far been considered as of having a prohibitively weak anisotropic spectrum [D. P. Shelton and L. Ulivi, J. Chem. Phys. 89, 149 (1988)]. Here, we report the first anisotropic spectrum of this overtone, at room temperature and for 13 gas densities ranging between 2 and 27 amagat. This spectrum is 10 times broader and 50 times weaker than the isotropic counterpart of the overtone [D. Kremer, F. Rachet, and M. Chrysos, J. Chem. Phys. 138, 174308 (2013)] and its profile much more sensitive to pressure effects than the profile of the isotropic spectrum. From our measurements an accurate value for the anisotropy matrix-element |?000020|??|000000?| was derived and this value was found to be comparable to that of the mean-polarizability ((000020), ?{sup ¯} (000000)). Among other conclusions our study offers compelling evidence that, in Raman spectroscopy, highly polarized bands or tiny depolarization ratios are not necessarily incompatible with large polarizability anisotropy transition matrix-elements. Our findings and the way to analyze them suggest that new strategies should be developed on the basis of the complementarity inherent in independent incoherent Raman experiments that run with two different incident-beam polarizations, and on concerted efforts to ab initio calculate accurate data for first and second polarizability derivatives. Values for these derivatives are still rarities in the literature of SF{sub 6}.

  13. Structural dynamics of phenylisothiocyanate in the light-absorbing excited states: Resonance Raman and complete active space self-consistent field calculation study

    SciTech Connect (OSTI)

    Ouyang, Bing, E-mail: ouyangbing.zj@foxmail.com; Xue, Jia-Dan, E-mail: jenniexue@126.com; Zheng, Xuming, E-mail: zhengxuming126@126.com, E-mail: zxm@zstu.edu.cn, E-mail: fangwh@dnu.edu.cn [Department of Chemistry, Zhejiang Sci-Tech University, Hangzhou 310018 (China)] [Department of Chemistry, Zhejiang Sci-Tech University, Hangzhou 310018 (China); Fang, Wei-Hai, E-mail: zxm@zstu.edu.cn, E-mail: fangwh@dnu.edu.cn, E-mail: fangwh@dnu.edu.cn [Department of Chemistry, Beijing Normal University, Beijing 100875 (China)] [Department of Chemistry, Beijing Normal University, Beijing 100875 (China)

    2014-05-21

    The excited state structural dynamics of phenyl isothiocyanate (PITC) after excitation to the light absorbing S{sub 2}(A?), S{sub 6}(A?), and S{sub 7}(A?) excited states were studied by using the resonance Raman spectroscopy and complete active space self-consistent field method calculations. The UV absorption bands of PITC were assigned. The vibrational assignments were done on the basis of the Fourier transform (FT)-Raman and FT-infrared measurements, the density-functional theory computations, and the normal mode analysis. The A-, B-, and C-bands resonance Raman spectra in cyclohexane, acetonitrile, and methanol solvents were, respectively, obtained at 299.1, 282.4, 266.0, 252.7, 228.7, 217.8, and 208.8 nm excitation wavelengths to probe the corresponding structural dynamics of PITC. The results indicated that the structural dynamics in the S{sub 2}(A?), S{sub 6}(A?), and S{sub 7}(A?) excited states were very different. The conical intersection point CI(S{sub 2}/S{sub 1}) were predicted to play important role in the low-lying excited state decay dynamics. Two major decay channels were predicted for PITC upon excitation to the S{sub 2}(A?) state: the radiative S{sub 2,min} ? S{sub 0} transition and the nonradiative S{sub 2} ? S{sub 1} internal conversion via CI(S{sub 2}/S{sub 1}). The differences in the decay dynamics between methyl isothiocyanate and PITC in the first light absorbing excited state were discussed. The role of the intersystem crossing point ISC(S{sub 1}/T{sub 1}) in the excited state decay dynamics of PITC is evaluated.

  14. Tuning the interaction between propagating and localized surface plasmons for surface enhanced Raman scattering in water for biomedical and environmental applications

    SciTech Connect (OSTI)

    Shioi, Masahiko; Jans, Hilde; Lodewijks, Kristof; Van Dorpe, Pol; Lagae, Liesbet; Kawamura, Tatsuro

    2014-06-16

    With a view to biomedical and environmental applications, we investigate the plasmonic properties of a rectangular gold nanodisk array in water to boost surface enhanced Raman scattering (SERS) effects. To control the resonance wavelengths of the surface plasmon polariton and the localized surface plasmon, their dependence on the array period and diameter in water is studied in detail using a finite difference time domain method. A good agreement is obtained between calculated resonant wavelengths and those of gold nanodisk arrays fabricated using electron beam lithography. For the optimized structure, a SERS enhancement factor of 7.8?×?10{sup 7} is achieved in water experimentally.

  15. Nonequilibrium vibrational excitation of H{sub 2} in radiofrequency discharges: A theoretical approach based on coherent anti-Stokes Raman spectroscopy measurements

    SciTech Connect (OSTI)

    Hassouni, K.; Lombardi, G.; Gicquel, A.; Capitelli, M.; Shakhatov, V.A.; De Pascale, O.

    2005-07-15

    Vibrational and rotational experimental temperatures of molecular hydrogen obtained by coherent anti-Stokes Raman spectroscopy in radiofrequency inductive plasmas have been analyzed and interpreted in terms of vibration, electron, dissociation-recombination, and attachment kinetics by using a sophisticated kinetic model recently developed. The analysis clarifies the role of atomic hydrogen in affecting the vibrational content of the molecules. Theoretical plasma composition and population and electron energy distributions are presented as a function of the recombination coefficient {gamma}{sub H} of atomic hydrogen on the surfaces. The agreement between theoretical and experimental results is achieved for recombination coefficients consistent with those found in the literature.

  16. Synchrotron X-ray diffraction and Raman spectroscopy of Ln{sub 3}NbO{sub 7} (Ln=La, Pr, Nd, Sm-Lu) ceramics obtained by molten-salt synthesis

    SciTech Connect (OSTI)

    Siqueira, K.P.F.; Soares, J.C.; Granado, E.; Bittar, E.M.; Paula, A.M. de; Moreira, R.L.; Dias, A.

    2014-01-15

    Ln{sub 3}NbO{sub 7} (Ln=La, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu) ceramics were obtained by molten-salt synthesis and their structures were systematically investigated by synchrotron X-ray diffraction (SXRD), second harmonic generation (SHG) and Raman spectroscopy. It was observed that ceramics with the largest ionic radii (La, Pr, Nd) crystallized into the Pmcn space group, while the ceramics with intermediate ionic radii (Sm-Gd) exhibited a different crystal structure belonging to the Ccmm space group. For this last group of ceramics, this result was corroborated by SHG and Raman scattering and ruled out any possibility for the non-centrosymmetric C 222{sub 1} space group, solving a recent controversy in the literature. Finally, according to SXRD, Tb-Lu containing samples exhibited an average defect fluorite structure (Fm3{sup ¯}m space group). Nonetheless, broad scattering at forbidden Bragg reflections indicates the presence of short-range domains with lower symmetry. Vibrational spectroscopy showed the presence of six Raman-active modes, inconsistent with the average cubic fluorite structure, and in line with the existence of lower-symmetry nano-domains immersed in the average fluorite structure of these ceramics. - Graphical abstract: Raman spectrum for Sm{sub 3}NbO{sub 7} ceramics showing their 27 phonon modes adjusted through Lorentzian lines. According to synchrotron X-ray diffraction and Raman scattering, this material belongs to the space group Cmcm. Display Omitted - Highlights: • Ln{sub 3}NbO{sub 7} ceramics were obtained by molten-salt synthesis. • SXRD, SHG and Raman scattering confirmed orthorhombic and cubic structures. • Ccmm instead of C222{sub 1} is the correct structure for Sm–Gd ceramics. • Pmcn space group was confirmed for La-, Pr- and Nd-based ceramics. • For Tb–Lu ceramics, ordered domains of a pyrochlore structure were observed.

  17. Growth of ring ripple in a collisionless plasma in relativistic-ponderomotive regime and its effect on stimulated Raman backscattering process

    SciTech Connect (OSTI)

    Rawat, Priyanka; Purohit, Gunjan, E-mail: gunjan75@gmail.com [Department of Physics, DAV PG College, Dehradun, Uttarakhand 248001 (India); Gauniyal, Rakhi [Uttarakhand Technical University, Dehradun, Uttarakhand 248007 (India)

    2014-06-15

    A theoretical and numerical study has been made of the propagation of a ring rippled laser beam in collisionless plasma with dominant relativistic ponderomotive nonlinearity and its effect on the excitation of electron plasma wave and stimulated Raman backscattering process. The growth of ring ripple, riding on an intense Gaussian laser beam in plasma has also been studied. A paraxial-ray and WKB approximation has been invoked to understand the nature of propagation of the ring rippled Gaussian laser beam in plasma, electron plasma wave and back reflectivity under the influence of both nonlinearities. The growth rate and focusing of a ring rippled beam is found to be considerably affected by the power of the main beam and the phase angle between the electric vectors of the main beam and the ring ripple. It has also been observed that the focusing is released by the coupling of relativistic and ponderomotive nonlinearities, which significantly affected the dynamics of the excitation of electron plasma wave and back reflectivity of stimulated Raman scattering (SRS). Due to the strong coupling between ring rippled laser beam and the excited electron plasma wave, back reflectivity of SRS is enhanced. It has been observed from the computational results that the effect of the increased intensity leads to suppression of SRS back reflectivity. The results have been presented for established laser and plasma parameters.

  18. Direct Growth Graphene on Cu Nanoparticles by Chemical Vapor Deposition as Surface-Enhanced Raman Scattering Substrate for Label-Free Detection of Adenosine

    E-Print Network [OSTI]

    Xu, Shicai; Jiang, Shouzhen; Wang, Jihua; Wei, Jie; Xu, Shida; Liu, Hanping

    2015-01-01

    We present a graphene/Cu nanoparticle hybrids (G/CuNPs) system as a surface-enhanced Raman scattering (SERS) substrate for adenosine detection. The Cu nanoparticles wrapped around a monolayer graphene shell were directly synthesized on flat quartz by chemical vapor deposition in a mixture of methane and hydrogen. The G/CuNPs showed an excellent SERS enhancement activity for adenosine. The minimum detected concentration of the adenosine in serum was demonstrated as low as 5 nM, and the calibration curve showed a good linear response from 5 to 500 nM. The capability of SERS detection of adenosine in real normal human urine samples based on G/CuNPs was also investigated and the characteristic peaks of adenosine were still recognizable. The reproducible and the ultrasensitive enhanced Raman signals could be due to the presence of an ultrathin graphene layer. The graphene shell was able to enrich and fix the adenosine molecules, which could also efficiently maintain chemical and optical stability of G/CuNPs. Based...

  19. Searching for minicharged particles via birefringence, dichroism and Raman spectroscopy of the vacuum polarized by a high-intensity laser wave

    SciTech Connect (OSTI)

    Villalba-Chávez, S. Müller, C.

    2013-12-15

    Absorption and dispersion of probe photons in the field of a high-intensity circularly polarized laser wave are investigated. The optical theorem is applied for determining the absorption coefficients in terms of the imaginary part of the vacuum polarization tensor. Compact expressions for the vacuum refraction indices and the photon absorption coefficients are obtained in various asymptotic regimes of interest. The outcomes of this analysis reveal that, far from the region relatively close to the threshold of the two-photon reaction, the birefringence and dichroism of the vacuum are small and, in some cases, strongly suppressed. On the contrary, in a vicinity of the region in which the photo-production of a pair occurs, these optical properties are manifest with lasers of moderate intensities. We take advantage of such a property in the search of minicharged particles by considering high-precision polarimetric experiments. In addition, Raman-like electromagnetic waves resulting from the inelastic part of the vacuum polarization tensor are suggested as an alternative form for finding exclusion limits on these hypothetical charge carriers. The envisaged parameters of upcoming high-intensity laser facilities are used for establishing upper bounds on the minicharged particles. -- Highlights: •Via dichroism and birefringence of the vacuum by a strong laser wave, minicharged particles can be probed. •The discovery potential is the highest in a vicinity of the first pair production threshold. •As alternative observable, Raman scattered waves are put forward.

  20. Raman spectra of R{sub 2}O{sub 3} (R—rare earth) sesquioxides with C-type bixbyite crystal structure: A comparative study

    SciTech Connect (OSTI)

    Abrashev, M. V.; Todorov, N. D.; Geshev, J.

    2014-09-14

    Raman spectra of R{sub 2}O{sub 3} (R—Sc, Er, Y, Ho, Gd, Eu, and Sm) powders with C-type bixbyite crystal structure are measured. With the help of these data and ones, previously published for other oxides from the same structural family, general dependencies of the frequencies of the Raman peaks on the cubic crystal unit cell parameter are constructed. Using these dependencies and knowing the symmetry of the peaks for one of the oxides, determined from previous single-crystal measurements, it is possible to find out the symmetry of the peaks from the spectra of all compounds. It was found that the frequency of the six lowest frequency peaks scales with the square root of the mass of the rare earth showing that mainly R ions take part in these vibrations. These results agree with performed here lattice dynamical calculations. The anomalous softening of the frequency of some peaks in the spectra of Eu{sub 2}O{sub 3} is discussed.

  1. In situ apparatus for the study of clathrate hydrates relevant to solar system bodies using synchrotron X-ray diffraction and Raman spectroscopy

    E-Print Network [OSTI]

    Day, Sarah J; Evans, Aneurin; Parker, Julia E

    2015-01-01

    Clathrate hydrates are believed to play a significant role in various solar system environments, e.g. comets, and the surfaces and interiors of icy satellites, however the structural factors governing their formation and dissociation are poorly understood. We demonstrate the use of a high pressure gas cell, combined with variable temperature cooling and time-resolved data collection, to the in situ study of clathrate hydrates under conditions relevant to solar system environments. Clathrates formed and processed within the cell are monitored in situ using synchrotron X-ray powder diffraction and Raman spectroscopy. X-ray diffraction allows the formation of clathrate hydrates to be observed as CO2 gas is applied to ice formed within the cell. Complete conversion is obtained by annealing at temperatures just below the ice melting point. A subsequent rise in the quantity of clathrate is observed as the cell is thermally cycled. Four regions between 100-5000cm-1 are present in the Raman spectra that carry feature...

  2. Phonon renormalization and Raman spectral evolution through amorphous to crystalline transitions in Sb{sub 2}Te{sub 3} thin films

    SciTech Connect (OSTI)

    Secor, Jeff; Zhao, Lukas; Krusin-Elbaum, Lia; Harris, Matt A.; Deng, Haiming; Raoux, Simone

    2014-06-02

    A symmetry specific phonon mode renormalization is observed across an amorphous to crystalline phase transformation in thin films of the topological material Sb{sub 2}Te{sub 3} using Raman spectroscopy. We present evidence for local crystalline symmetry in the amorphous state, eventhough, the q?=?0 Raman selection rule is broken due to strong structural disorder. At crystallization, the in-plane polarized (E{sub g}{sup 2}) mode abruptly sharpens while the out-of-plane polarized (A{sub 1g}) modes are only weakly effected. This effect unique to the E{sub g} symmetry is exceptional considering that polarized spectra and comparison of the single phonon density of states between the amorphous and crystalline phases suggest that short range order of the amorphous phase is, on the average, similar to that of the crystalline material while electrical transport measurements reveal a sharp insulator-to-metal transition. Our findings point to the important role of anisotropic disorder affecting potential applications of topological and phase-change based electronics.

  3. Raman Nanometrology of Graphene

    E-Print Network [OSTI]

    Calizo, Irene Gonzales

    2009-01-01

    graphene is a promising material for the electronic applications beyond the conventional complementary metal-oxide semiconductor (graphene is considered for applications in the integrated circuits beyond the conventional silicon complementary metal- oxide semiconductor

  4. Raman Nanometrology of Graphene

    E-Print Network [OSTI]

    Calizo, Irene Gonzales

    2009-01-01

    2D) electron gas physics it reveals, graphene is a promising material for the electronic applications beyond the conventional complementary metal-oxide semiconductor (

  5. Raman spectroscopy of single human tumour cells exposed to ionizing radiation in vitro This article has been downloaded from IOPscience. Please scroll down to see the full text article.

    E-Print Network [OSTI]

    Brolo, Alexandre G.

    Raman spectroscopy of single human tumour cells exposed to ionizing radiation in vitro This article tissue samples which will survive long enough in a lab to perform a radiation experiment. Animal in non-human systems to radiation therapy patient outcomes. As such, prescribed doses for tumour control

  6. Molecular near-field antenna effect in resonance hyper-Raman scattering: Intermolecular vibronic intensity borrowing of solvent from solute through dipole-dipole and dipole-quadrupole interactions

    SciTech Connect (OSTI)

    Shimada, Rintaro; Hamaguchi, Hiro-o

    2014-05-28

    We quantitatively interpret the recently discovered intriguing phenomenon related to resonance Hyper-Raman (HR) scattering. In resonance HR spectra of all-trans-?-carotene (?-carotene) in solution, vibrations of proximate solvent molecules are observed concomitantly with the solute ?-carotene HR bands. It has been shown that these solvent bands are subject to marked intensity enhancements by more than 5 orders of magnitude under the presence of ?-carotene. We have called this phenomenon the molecular-near field effect. Resonance HR spectra of ?-carotene in benzene, deuterated benzene, cyclohexane, and deuterated cyclohexane have been measured precisely for a quantitative analysis of this effect. The assignments of the observed peaks are made by referring to the infrared, Raman, and HR spectra of neat solvents. It has been revealed that infrared active and some Raman active vibrations are active in the HR molecular near-field effect. The observed spectra in the form of difference spectra (between benzene/deuterated benzene and cyclohexane/deuterated cyclohexane) are quantitatively analyzed on the basis of the extended vibronic theory of resonance HR scattering. The theory incorporates the coupling of excited electronic states of ?-carotene with the vibrations of a proximate solvent molecule through solute–solvent dipole–dipole and dipole–quadrupole interactions. It is shown that the infrared active modes arise from the dipole–dipole interaction, whereas Raman active modes from the dipole–quadrupole interaction. It is also shown that vibrations that give strongly polarized Raman bands are weak in the HR molecular near-field effect. The observed solvent HR spectra are simulated with the help of quantum chemical calculations for various orientations and distances of a solvent molecule with respect to the solute. The observed spectra are best simulated with random orientations of the solvent molecule at an intermolecular distance of 10 Å.

  7. Development and Deployment of a Compact Eye-Safe Scanning Differential absorption Lidar (DIAL) for Spatial Mapping of Carbon Dioxide for Monitoring/Verification/Accounting at Geologic Sequestration Sites

    SciTech Connect (OSTI)

    Repasky, Kevin

    2014-03-31

    A scanning differential absorption lidar (DIAL) instrument for monitoring carbon dioxide has been developed. The laser transmitter uses two tunable discrete mode laser diodes (DMLD) operating in the continuous wave (cw) mode with one locked to the online absorption wavelength and the other operating at the offline wavelength. Two in-line fiber optic switches are used to switch between online and offline operation. After the fiber optic switch, an acousto- optic modulator (AOM) is used to generate a pulse train used to injection seed an erbium doped fiber amplifier (EDFA) to produce eye-safe laser pulses with maximum pulse energies of 66 {micro}J, a pulse repetition frequency of 15 kHz, and an operating wavelength of 1.571 {micro}m. The DIAL receiver uses a 28 cm diameter Schmidt-Cassegrain telescope to collect that backscattered light, which is then monitored using a photo-multiplier tube (PMT) module operating in the photon counting mode. The DIAL instrument has been operated from a laboratory environment on the campus of Montana State University, at the Zero Emission Research Technology (ZERT) field site located in the agricultural research area on the western end of the Montana State University campus, and at the Big Sky Carbon Sequestration Partnership site located in north-central Montana. DIAL data has been collected and profiles have been validated using a co-located Licor LI-820 Gas Analyzer point sensor.

  8. Imaging of the spatial distribution of atoms in an optical-breakdown plasma with one-dimensional coherent hyper-Raman scattering

    SciTech Connect (OSTI)

    Akimov, Denis A; Zheltikov, Aleksei M; Koroteev, Nikolai I; Naumov, A N; Fedotov, Andrei B; Miles, R B; Sidorov-Biryukov, D A

    1998-12-31

    A technique based on coherent four-wave mixing with a hyper-Raman resonance in wide beams was developed for line-by-line reconstruction of the spatial distribution of excited atoms in a laser-produced plasma. This method was used to study the spatial distribution of excited lead atoms in an optical-breakdown plasma formed on a metal target. A comparison was made of the technique of constructing plasma images line-by-line with a four-photon technique of point-by-point measurements. Estimates were obtained of the spatial resolution of the proposed technique. Potential applications of this approach in plasma diagnostics were analysed. (interaction of laser radiation with matter. laser plasma)

  9. Phase transitions in heated Sr{sub 2}MgTeO{sub 6} double perovskite oxide probed by X-ray diffraction and Raman spectroscopy

    SciTech Connect (OSTI)

    Manoun, Bouchaib Tamraoui, Y.; Lazor, P.; Yang, Wenge

    2013-12-23

    Double-perovskite oxide Sr{sub 2}MgTeO{sub 6} has been synthetized, and its crystal structure was probed by the technique of X-ray diffraction at room temperature. The structure is monoclinic, space group I2/m. Temperature-induced phase transitions in this compound were investigated by Raman spectroscopy up to 550?°C. Two low-wavenumber modes corresponding to external lattice vibrations merge at temperature of around 100?°C, indicating a phase transition from the monoclinic (I2/m) to the tetragonal (I4/m) structure. At 300?°C, changes in the slopes of temperature dependencies of external and O–Te–O bending modes are detected and interpreted as a second phase transition from the tetragonal (I4/m) to the cubic (Fm-3m) structure.

  10. In situ resonant Raman scattering and reversible photoinduced structural change in YBa{sub 2}Cu{sub 3}O{sub 6+x}

    SciTech Connect (OSTI)

    Osada, Minoru; Kaell, Mikael; Baeckstroem, Joakim; Kakihana, Masato; Andersen, Niels Hessel; Boerjesson, Lars

    2005-06-01

    We report on bidirectional photoswitching associated with the CuO chains in oxygen-deficient YBa{sub 2}Cu{sub 3}O{sub 6+x} single crystals. By varying the wavelength of light polarized along the CuO chains, the material can be reversibly switched between two metastable states characterized by the existence or absence of a specific Raman scattering resonance. A comparison of the spectral efficiencies for this photoswitching with analogous data for the persistent photoconductivity and photoconductivity quenching effects suggests that the two phenomena have the same microscopic origin. We argue that the effects are due to photoinduced Cu-O charge-transfer excitations, which destabilize chains of different length depending on wavelength, and promote the growth of thermally inaccessible oxygen ordering configurations.

  11. Infrared and Raman spectra of the fluoroxysulfate ion, SO/sub 4/F/sup -1 -/, and of fluorine perchlorate, ClO/sub 4/F

    SciTech Connect (OSTI)

    Appelman, E.H.; Basile, L.J.; Kim, H.

    1982-07-01

    The infrared and Raman spectra of solid cesium and rubidium fluoroxysulfates, CsSO/sub 4/F and RbSO/sub 4/F, have been measured, along with the gas-phase spectra of the isoelectronic molecule fluorine perchlorate, ClO/sub 4/F. The spectra are consistent with a perchloric acid type structure of C/sub s/ symmetry, and the vibrational bands have been assigned with reference to the analogous species of C/sub 3..nu../ symmetry: the fluorosulfate ion, SO/sub 3/F/sup -/, and perchloryl fluoride, ClO/sub 3/F. Normal-coordinate analyses have been carried out for both ClO/sub 4/F and SO/sub 4/F/sup -/. 6 figures, 4 tables.

  12. Near-resonance enhanced O2 detection for dual-broadband pure rotational coherent anti-Stokes Raman scattering with an ultraviolet-visible setup at 266 nm

    SciTech Connect (OSTI)

    Schenk, Martin; Seeger, Thomas; Leipertz, Alfred

    2005-07-01

    Broadband and dual-broadband coherent anti-Stokes Raman scattering (CARS) are widely established tools for nonintrusive gas diagnostics. Up to now the investigations have been mainly performed for electronic nonresonant conditions of the gas species of interest. We report on the enhancement of the O2-N2 detection limit of dual-broadband pure rotational CARS by shifting the wavelength of the narrowband pump laser from the commonly used 532-266 nm. This enhancement is caused when the Schumann-Runge absorption band is approached near 176 nm. The principal concept of this experiment, i.e., covering the Raman resonance with a single- or dual-broadband combination of lasers in the visible range and moving only the narrowband probe laser near or directly into electronic resonant conditions in the UV range, should also be applicable to broadband CARS experiments to directly exploit electronic resonance effects for the purpose of single-shot concentration measurements of minority species. To quantify the enhancement in O2 sensitivity, comparative measurements at both a 266 and a 532 nm narrowband pump laser wavelength are presented, employing a 4-dicyanomethylene-2-methyl-6-(p-dimethylaminostyryl)-4H-pyram (DCM) dye laser as a broadband laser source at 635 nm. An increase of approximately 13% in the ratio of the rotational CARS cross sections of O2 and N2 was obtained. The broad spectral width of the CARS excitation profile was approximately equal for both setups. Further enhancement should be achievable by shifting the narrowband pump laser closer toward 176 nm, for example, with a frequency-doubled optical parametric oscillator or an excimer laser. The principal concept of this experiment should also be applicable to broadband CARS experiments to directly exploit electronic resonance effects of the narrowband pump laser with electronic transitions of minority species for the purpose of single-shot concentration measurements of those species.

  13. Sci—Fri AM: Mountain — 04: Label-free Raman spectroscopy of single tumour cells detects early radiation-induced glycogen synthesis associated with increased radiation resistance

    SciTech Connect (OSTI)

    Matthews, Q; Lum, JJ; Isabelle, M; Harder, S; Jirasek, A; Brolo, AG

    2014-08-15

    Purpose: To use label-free Raman spectroscopy (RS) for early treatment monitoring of tumour cell radioresistance. Methods: Three human tumour cell lines, two radioresistant (H460, SF{sub 2} = 0.57 and MCF7, SF{sub 2} = 0.70) and one radiosensitive (LNCaP, SF{sub 2} = 0.36), were irradiated with single fractions of 2, 4, 6, 8 or 10 Gy. In additional experiments, H460 and MCF7 cells were irradiated under co-treatment with the anti-diabetic drug metformin, a known radiosensitizing agent. Treated and control cultures were analyzed with RS daily for 3 days post-treatment. Single-cell Raman spectra were acquired from 20 live cells per sample, and experiments were repeated in triplicate. The combined data sets were analyzed with principal component analysis using standard algorithms. Cells from each culture were also subjected to standard assays for viability, proliferation, cell cycle, and radiation clonogenic survival. Results: The radioresistant cells (H460, MCF7) exhibited a RS molecular radiation response signature, detectable as early as 1 day post-treatment, of which radiation-induced glycogen synthesis is a significant contributor. The radiosensitive cells (LNCaP) exhibited negligible glycogen synthesis. Co-treatment with metformin in MCF7 cells blocked glycogen synthesis, reduced viability and proliferation, and increased radiosensitivity. Conversely, metformin co-treatment in H460 cells did not produce these same effects; importantly, both radiation-induced synthesis of glycogen and radiosensitivity were unaffected. Conclusions: Label-free RS can detect early glycogen synthesis post-irradiation, a previously undocumented metabolic mechanism associated with tumour cell radioresistance that can be targeted to increase radiosensitivity. RS monitoring of intratumoral glycogen may provide new opportunities for personalized combined modality radiotherapy treatments.

  14. Laser Raman spectroscopy study of the zinc and bromide ion complex equilibrium in zinc/bromine battery electrolytes. [2M ZnBr/sub 2/ and 1M KBr solution

    SciTech Connect (OSTI)

    Grimes, P.G.; Larrabee, J.A.

    1985-01-01

    Laser Raman spectroscopy was used to study the zinc and bromide ion complex equilibrium in zinc bromine battery model electrolytes. Solutions of zinc bromide with added KBr, HBr and N-methyl, N-ethyl morpholinium (MEM) bromide were examined and compared. Solutions studied ranged from 1 to 3 molar in zinc and from 2.5 to 8 molar in bromide. A typical Raman spectrum of a zinc bromide solution is shown in Figure 1. Each of the zinc species is identified, Zn/sup + +/ (aq), ZnBr/sup +/, ZnBr/sub 2/ (aq), ZnBr/sub 3//sup -/ and ZnBr/sub 4//sup 2 -/. By the use of peak heights or deconvolution/integration along with published Raman cross sections, the amount of each zinc species could be quantitatively determined. The addition of bromide ions to the zinc bromide solutions will shift the equilibrium toward higher bromide complexes. The added cations will influence the shifts. It has been noted that the conductivity of the electrolyte decreases when the quaternary ammonium ions are present compared to cations such as potassium or hydrogen. Significantly more free zinc is present in zinc bromide solutions with added KBr than with either MEMBr or HBr. Shifts are also noted with the other zinc ion containing species. It appears that the quaternary ammonium ions and possibly the pH could have a stabilizing effect on zinc bromide complex ion formation. 2 figs.

  15. A high resolution and large solid angle x-ray Raman spectroscopy end-station at the Stanford Synchrotron Radiation Lightsource

    SciTech Connect (OSTI)

    Sokaras, D.; Nordlund, D.; Weng, T.-C.; Velikov, P.; Wenger, D.; Garachtchenko, A.; George, M.; Borzenets, V.; Johnson, B.; Rabedeau, T.; Mori, R. Alonso; Bergmann, U.; Qian, Q.

    2012-04-15

    We present a new x-ray Raman spectroscopy end-station recently developed, installed, and operated at the Stanford Synchrotron Radiation Lightsource. The end-station is located at wiggler beamline 6-2 equipped with two monochromators-Si(111) and Si(311) as well as collimating and focusing optics. It consists of two multi-crystal Johann type spectrometers arranged on intersecting Rowland circles of 1 m diameter. The first one, positioned at the forward scattering angles (low-q), consists of 40 spherically bent and diced Si(110) crystals with 100 mm diameters providing about 1.9% of 4{pi} sr solid angle of detection. When operated in the (440) order in combination with the Si (311) monochromator, an overall energy resolution of 270 meV is obtained at 6462.20 eV. The second spectrometer, consisting of 14 spherically bent Si(110) crystal analyzers (not diced), is positioned at the backward scattering angles (high-q) enabling the study of non-dipole transitions. The solid angle of this spectrometer is about 0.9% of 4{pi} sr, with a combined energy resolution of 600 meV using the Si (311) monochromator. These features exceed the specifications of currently existing relevant instrumentation, opening new opportunities for the routine application of this photon-in/photon-out hard x-ray technique to emerging research in multidisciplinary scientific fields, such as energy-related sciences, material sciences, physical chemistry, etc.

  16. Finite temperature effects on the X-ray absorption spectra of lithium compounds: First-principles interpretation of X-ray Raman measurements

    SciTech Connect (OSTI)

    Pascal, Tod A.; Prendergast, David, E-mail: dgprendergast@lbl.gov [The Molecular Foundry, Materials Science Division, Lawrence Berkeley National Laboratory (LBNL), Berkeley, California 94720 (United States)] [The Molecular Foundry, Materials Science Division, Lawrence Berkeley National Laboratory (LBNL), Berkeley, California 94720 (United States); Boesenberg, Ulrike; Kostecki, Robert; Richardson, Thomas J. [Environmental Energy Technologies Division, LBNL, Berkeley, California 94720 (United States)] [Environmental Energy Technologies Division, LBNL, Berkeley, California 94720 (United States); Weng, Tsu-Chien; Sokaras, Dimosthenis; Nordlund, Dennis [Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Stanford, California 94720 (United States)] [Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Stanford, California 94720 (United States); McDermott, Eamon; Moewes, Alexander [University of Saskatchewan, Department of Physics and Engineering Physics, Saskatoon, Saskatchewan S7N 5E2 (Canada)] [University of Saskatchewan, Department of Physics and Engineering Physics, Saskatoon, Saskatchewan S7N 5E2 (Canada); Cabana, Jordi [Environmental Energy Technologies Division, LBNL, Berkeley, California 94720 (United States) [Environmental Energy Technologies Division, LBNL, Berkeley, California 94720 (United States); Department of Chemistry, University of Illinois at Chicago, Chicago, Illinois 60605 (United States)

    2014-01-21

    We elucidate the role of room-temperature-induced instantaneous structural distortions in the Li K-edge X-ray absorption spectra (XAS) of crystalline LiF, Li{sub 2}SO{sub 4}, Li{sub 2}O, Li{sub 3}N, and Li{sub 2}CO{sub 3} using high resolution X-ray Raman spectroscopy (XRS) measurements and first-principles density functional theory calculations within the eXcited electron and Core Hole approach. Based on thermodynamic sampling via ab initio molecular dynamics simulations, we find calculated XAS in much better agreement with experiment than those computed using the rigid crystal structure alone. We show that local instantaneous distortion of the atomic lattice perturbs the symmetry of the Li 1s core-excited-state electronic structure, broadening spectral line-shapes and, in some cases, producing additional spectral features. The excellent agreement with high-resolution XRS measurements validates the accuracy of our first-principles approach to simulating XAS, and provides both accurate benchmarks for model compounds and a predictive theoretical capability for identification and characterization of multi-component systems, such as lithium-ion batteries, under working conditions.

  17. Local structures of polar wurtzites Zn1-xMgxO studied by raman and 67Zn/25Mg NMR spectroscopies and by total neutron scattering

    SciTech Connect (OSTI)

    Proffen, Thomas E; Kim, Yiung- Il; Cadars, Sylvian; Shayib, Ramzy; Feigerle, Charles S; Chmelka, Bradley F; Seshadri, Ram

    2008-01-01

    Research in the area of polar semiconductor heterostructures has been growing rapidly, driven in large part by interest in two-dimensional electron gas (2DEG) systems. 2DEGs are known to form at heterojunction interfaces that bear polarization gradients. They can display extremely high electron mobilities, especially at low temperatures, owing to spatial confinement of carrier motions. Recent reports of 2DEG behaviors in Ga{sub 1-x}Al{sub x}N/GaN and Zn{sub 1-x}Mg{sub x}O/ZnO heterostructures have great significance for the development of quantum Hall devices and novel high-electron-mobility transistors (HEMTs). 2DEG structures are usually designed by interfacing a polar semiconductor with its less or more polar alloys in an epitaxial manner. Since the quality of the 2DEG depends critically on interface perfection, as well as the polarization gradient at the heterojunction, understanding compositional and structural details of the parent and alloy semiconductors is an important component in 2DEG design and fabrication. Zn{sub 1-x}Mg{sub x}O/ZnO is one of the most promising heterostructure types for studies of 2DEGs, due to the large polarization of ZnO, the relatively small lattice mismatch, and the large conduction band offsets in the Zn{sub 1-x}Mg{sub x}O/ZnO heterointerface. Although 2DEG formation in Zn{sub 1-x}Mg{sub x}O/ZnO heterostructures have been researched for some time, a clear understanding of the alloy structure of Zn{sub 1-x}Mg{sub x}O is currently lacking. Here, we conduct a detailed and more precise study of the local structure of Zn{sub 1-x}Mg{sub x}O alloys using Raman and solid-state nuclear magnetic resonance (NMR), in conjunction with neutron diffraction techniques.

  18. Evaluating Global Aerosol Models and Aerosol and Water Vapor Properties Near Clouds

    SciTech Connect (OSTI)

    Turner, David, D.; Ferrare, Richard, A.

    2011-07-06

    The 'Evaluating Global Aerosol Models and Aerosol and Water Vapor Properties Near Clouds' project focused extensively on the analysis and utilization of water vapor and aerosol profiles derived from the ARM Raman lidar at the Southern Great Plains ARM site. A wide range of different tasks were performed during this project, all of which improved quality of the data products derived from the lidar or advanced the understanding of atmospheric processes over the site. These activities included: upgrading the Raman lidar to improve its sensitivity; participating in field experiments to validate the lidar aerosol and water vapor retrievals; using the lidar aerosol profiles to evaluate the accuracy of the vertical distribution of aerosols in global aerosol model simulations; examining the correlation between relative humidity and aerosol extinction, and how these change, due to horizontal distance away from cumulus clouds; inferring boundary layer turbulence structure in convective boundary layers from the high-time-resolution lidar water vapor measurements; retrieving cumulus entrainment rates in boundary layer cumulus clouds; and participating in a field experiment that provided data to help validate both the entrainment rate retrievals and the turbulent profiles derived from lidar observations.

  19. Dependence of the surface topology and raman scattering spectra of Ge{sub x}Si{sub 1-x}/Si films on the composition variation over the layer thickness

    SciTech Connect (OSTI)

    Lunin, L. S.; Sysoev, I. A. [Russian Academy of Sciences, Southern Scientific Center (Russian Federation); Bavizhev, M. D.; Lapin, V. A., E-mail: viacheslavlapin@yandex.ru [North Caucasus Federal University (Russian Federation); Kuleshov, D. S.; Malyavin, F. F. [South Russian State Technical University (Russian Federation)

    2013-05-15

    The surface topology and Raman scattering spectra of Ge{sub x}Si{sub 1-x}/Si(100) films are investigated in dependence of the composition variation over the film thickness. It is shown that the character of the Ge content variation in the Ge{sub x}Si{sub 1-x} alloy at the constant cumulative Ge fraction in the film (x{sub int} = 0.5) affects the surface morphology of the grown Ge{sub x}Si{sub 1-x}/Si layer. The heterostructures were grown by molecular-beam epitaxy.

  20. Efficient Open Source Lidar for Desktop Users

    E-Print Network [OSTI]

    Flanagan, Jacob Patrick

    2015-01-01

    handle this data in a more efficiently manner has become athe search methods for efficiently extracting the “area ofbased analysis, their efficiently falls short when handling

  1. Systematic Sampling of Scanning Lidar Swaths 

    E-Print Network [OSTI]

    Marcell, Wesley Tyler

    2011-02-22

    classical SyS arises from fact that SyS induces within-level (h) and between-level components of variance and that the between-level component is unmeasured (Cochran, 1977). The SRS-based estimator (2) is unbiased if the order of units... squared error is depicted differently in the graphics of Appendix E. On each page the panels are histograms of MSE for all h = 1, ? , k and i= 1, 2? , n possibilities, each 29 panel representing one of our eight estimators. The SRS histogram...

  2. Sandia Multispectral Airborne Lidar for UAV Deployment

    SciTech Connect (OSTI)

    Daniels, J.W.; Hargis,Jr. P.J.; Henson, T.D.; Jordan, J.D.; Lang, A.R.; Schmitt, R.L.

    1998-10-23

    Sandia National Laboratories has initiated the development of an airborne system for W laser remote sensing measurements. System applications include the detection of effluents associated with the proliferation of weapons of mass destruction and the detection of biological weapon aerosols. This paper discusses the status of the conceptual design development and plans for both the airborne payload (pointing and tracking, laser transmitter, and telescope receiver) and the Altus unmanned aerospace vehicle platform. Hardware design constraints necessary to maintain system weight, power, and volume limitations of the flight platform are identified.

  3. ARM - Campaign Instrument - co2lidar

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of NaturalDukeWakefieldSulfateSciTechtail.TheoryTuesday,air Comments? We would love to hear from you! Send us a note belowlidar

  4. ARM - Campaign Instrument - lidar-dial

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of NaturalDukeWakefieldSulfateSciTechtail.TheoryTuesday,air Comments? WegovInstrumentsirt-airgovInstrumentslidar-dial Comments?

  5. LiDAR | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QA J-E-1 SECTION J APPENDIXsource History ViewInformationWinds Jump to:LaredoLeelanauLeonicsLewisville,LiLiDAR

  6. Doppler Lidar Wind Value-Added Product

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration would like submit theCovalentLaboratory |Sector Full reportTown2008Donald Raby Donald_ -498

  7. Micropulse Lidar The ARM Program studies

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration wouldMass map shines light on darkMicroorganisms to Speed Production of Biofuels Oak1 Micropulse

  8. Phase transformations in multiferroic Bi{sub 1?x}La{sub x}Fe{sub 1?y}Ti{sub y}O{sub 3} ceramics probed by temperature dependent Raman scattering

    SciTech Connect (OSTI)

    Xu, L. P.; Zhang, X. L.; Zhang, J. Z.; Hu, Z. G. Chu, J. H.; Zhang, L. L.; Yu, J.

    2014-10-28

    Optical phonons and phase transitions of Bi{sub 1?x}La{sub x}Fe{sub 1?y}Ti{sub y}O{sub 3} (BLFTO, 0.02 ? x ? 0.12, 0.01 ? y ? 0.08) ceramics have been investigated by Raman scattering in the temperature range from 80 to 680?K. Four phase transitions around 140, 205, 570, and 640?K can be observed. The Raman modes are sensitive to the spin reorientation around 140 and 205?K, owing to the strong magnon-phonon coupling. The transformation around 570?K is a structural transition from rhombohedral to orthorhombic phase due to an external pressure induced by the chemical substitution. The anomalies of the phonon frequencies near Néel temperature T{sub N} have been discussed in the light of the multiferroicity. Moreover, it was found that the structural transition temperature and T{sub N} of BLFTO ceramics decrease towards room temperature with increasing doping composition as a result of size mismatch between substitution and host cations.

  9. JOURNAL OF RAMAN SPECTROSCOPY J. Raman Spectrosc. 2007; 38: 853858

    E-Print Network [OSTI]

    Lombardi, John R.

    enhancement in the FT-SERS spectrum of the out-of-plane ring system bending deformation mode at 729 cm-1 minimizing the sample size is an absolute priority. This paper will describe the identification as a dye for paper and silk, and it had a reputation for protecting paper from insect attack, owing to its

  10. Highly Efficient Coherent Raman Generation 

    E-Print Network [OSTI]

    Hua, Xia

    2014-08-04

    explore detection and sensing applications, and achieve further improvement of efficiency by using field enhancement due to surface plasmon resonances in aggregates of gold nanoparticles. By scanning the time delay of the probe pulse, we demonstrate a new...

  11. 32ND INTERNATIONAL COSMIC RAY CONFERENCE, BEIJING 2011 Atmospheric "Super Test Beam" for the Pierre Auger Observatory

    E-Print Network [OSTI]

    _spokespersons@fnal.gov Abstract: We present results from 200 hours of operation of an atmospheric super test beam system developed system combines a Raman backscatter LIDAR receiver with a calibrated pulsed UV laser system to generate Facilities (CLF [1] & XLF) generate tracks that are recorded by the Auger Observatory fluorescence detector

  12. Measurement of vibrational, gas, and rotational temperatures of H{sub 2} (X{sup 1} {sigma}{sub g}{sup +}) in radio frequency inductive discharge plasma by multiplex coherent anti-Stokes Raman scattering spectroscopy technique

    SciTech Connect (OSTI)

    Shakhatov, V.A.; De Pascale, O.; Capitelli, M.; Hassouni, K.; Lombardi, G.; Gicquel, A.

    2005-02-01

    Translational, rotational, and vibrational temperatures of H{sub 2} in radio frequency inductive discharge plasmas at pressures and power release ranges, respectively, of 0.5-8 torr and 0.5-2 W/cm{sup 3} have been measured by using multiplex coherent anti-Stokes Raman scattering (CARS) spectroscopy. Computational codes have been developed to determine the rotational and vibrational temperatures and to analyze H{sub 2} CARS spectrum for nonequilibrium conditions. The results show a decrease of the vibrational temperature from 4250 to 2800 K by increasing the pressure from 0.5 to 8 torr and a corresponding increase of the rotational temperature from 525 to 750 K.

  13. H irradiation effects on the GaAs-like Raman modes in GaAs{sub 1-x}N{sub x}/GaAs{sub 1-x}N{sub x}:H planar heterostructures

    SciTech Connect (OSTI)

    Giulotto, E. Geddo, M.; Patrini, M.; Guizzetti, G.; Felici, M.; Capizzi, M.; Polimeni, A.; Martelli, F.; Rubini, S.

    2014-12-28

    The GaAs-like longitudinal optical phonon frequency in two hydrogenated GaAs{sub 1-x}N{sub x}/GaAs{sub 1-x}N{sub x}:H microwire heterostructures—with similar N concentration, but different H dose and implantation conditions—has been investigated by micro-Raman mapping. In the case of GaAs{sub 0.991}N{sub 0.009} wires embedded in barriers where GaAs-like properties are recovered through H irradiation, the phonon frequency in the barriers undergoes a blue shift with respect to the wires. In GaAs{sub 0.992}N{sub 0.008} wires embedded in less hydrogenated barriers, the phonon frequency exhibits an opposite behavior (red shift). Strain, disorder, phonon localization effects induced by H-irradiation on the GaAs-like phonon frequency are discussed and related to different types of N-H complexes formed in the hydrogenated barriers. It is shown that the red (blue) character of the frequency shift is related to the dominant N-2H (N-3H) type of complexes. Moreover, for specific experimental conditions, an all-optical determination of the uniaxial strain field is obtained. This may improve the design of recently presented devices that exploit the correlation between uniaxial stress and the degree of polarization of photoluminescence.

  14. Simultaneous presence of (Si{sub 3}O{sub 10}){sup 8?} and (Si{sub 2}O{sub 7}){sup 6?} groups in new synthetic mixed sorosilicates: BaY{sub 4}(Si{sub 2}O{sub 7})(Si{sub 3}O{sub 10}) and isotypic compounds, studied by single-crystal X-ray diffraction, Raman spectroscopy and DFT calculations

    SciTech Connect (OSTI)

    Wierzbicka-Wieczorek, Maria; Többens, Daniel M.; Kolitsch, Uwe; Tillmanns, Ekkehart

    2013-11-15

    Three new, isotypic silicate compounds, BaY{sub 4}(Si{sub 2}O{sub 7})(Si{sub 3}O{sub 10}), SrYb{sub 4}(Si{sub 2}O{sub 7})(Si{sub 3}O{sub 10}) and SrSc{sub 4}(Si{sub 2}O{sub 7})(Si{sub 3}O{sub 10}), were synthesized using high-temperature flux growth techniques, and their crystal structures were solved from single-crystal X-ray intensity data: monoclinic, P2{sub 1}/m, with a=5.532(1)/5.469(1)/5.278(1), b=19.734(4)/19.447(4)/19.221(4), c=6.868(1)/6.785(1)/6.562(1) Å, ?=106.53(3)/106.20(3)/106.50(3)°, V=718.8(2)/693.0(2)/638.3(2) Å{sup 3}, R(F)=0.0225/0.0204/0.0270, respectively. The topology of the novel structure type contains isolated horseshoe-shaped Si{sub 3}O{sub 10} groups (Si–Si–Si=93.15–95.98°), Si{sub 2}O{sub 7} groups (Si–O{sub bridge}–Si=180°, symmetry-restricted) and edge-sharing M(1)O{sub 6} and M(2)O{sub 6} octahedra. Single-crystal Raman spectra of the title compounds were measured and compared with Raman spectroscopic data of chemically and topologically related disilicates and trisilicates, including BaY{sub 2}(Si{sub 3}O{sub 10}) and SrY{sub 2}(Si{sub 3}O{sub 10}). The band assignments are supported by additional theoretical calculation of Raman vibrations by DFT methods. - Graphical abstract: View of BaY{sub 4}(Si{sub 2}O{sub 7})(Si{sub 3}O{sub 10}) along [100], showing zigzag chains and the tri- and disilicate groups. The unit cell is outlined. Display Omitted - Highlights: • We report a novel interesting crystal structure type for mixed sorosilicates containing Y, Yb, and Sc. • Synthesis of such mixed sorosilicates is possible by a high-temperature flux-growth technique. • Calculation of Raman vibrations by advanced DFT methods allows a considerably improved interpretation of measured Raman spectra.

  15. Observations of Ferroelastic Switching by Raman Spectroscopy 

    E-Print Network [OSTI]

    Bolon, Amy Marie

    2012-02-14

    Thermal barrier coatings (TBCs) have become an important part of turbine technology by providing thermal protection to the underlying metallic components. These coatings are typically made from a zirconia-based ceramics ...

  16. Transcutaneous measurement of glucose using Raman spectroscopy

    E-Print Network [OSTI]

    Oh, Jeankun, 1968-

    2004-01-01

    Transcutaneous glucose measurement would provide the ability to obtain frequent measurements without the pain and risk of infection associated with obtaining a blood sample and eliminates the need for reagents. Because of ...

  17. FY2009 Run Campaign Highlights Roger Raman

    E-Print Network [OSTI]

    Princeton Plasma Physics Laboratory

    Capabilities for 2009: · Routine Li usage ( 65% of shots) · CHI absorber PF coils · HHFW antenna grounding to Retention Milestone Important for Understanding Li pumping, ITER T Retention PMI probe measurements show Li increases global retention from 87% to 93% in NBI-heated plasmas With Li Without Li 4 #12;NSTXNSTX

  18. Online Raman spectroscopy for bioprocess monitoring

    E-Print Network [OSTI]

    Gil, Gustavo Adolfo

    2005-01-01

    Online monitoring of bioprocesses is essential to expanding the potential of biotechnology. In this thesis, a system to estimate concentrations of chemical components of an Escherichia Coli fermentation growth medium via ...

  19. Raman spectroscopic investigation of the murine oocyte 

    E-Print Network [OSTI]

    Davidson, Bryony Kathryn

    2010-01-01

    Over recent years, the application of assisted reproductive techniques in the treatment of infertility has increased exponentially, yet these methodologies still remain inherently inefficient. It has long been established that the single greatest...

  20. Lane estimation for autonomous vehicles using vision and LIDAR

    E-Print Network [OSTI]

    Huang, Albert Shuyu

    2010-01-01

    Autonomous ground vehicles, or self-driving cars, require a high level of situational awareness in order to operate safely and eciently in real-world conditions. A system able to quickly and reliably estimate the location ...