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Sample records for nonlinear waveguides view

  1. All-optical switching in optically induced nonlinear waveguide couplers

    SciTech Connect (OSTI)

    Diebel, Falko Boguslawski, Martin; Rose, Patrick; Denz, Cornelia; Leykam, Daniel; Desyatnikov, Anton S.

    2014-06-30

    We experimentally demonstrate all-optical vortex switching in nonlinear coupled waveguide arrays optically induced in photorefractive media. Our technique is based on multiplexing of nondiffracting Bessel beams to induce various types of waveguide configurations. Using double- and quadruple-well potentials, we demonstrate precise control over the coupling strength between waveguides, the linear and nonlinear dynamics and symmetry-breaking bifurcations of guided light, and a power-controlled optical vortex switch.

  2. Dynamic time expansion and compression using nonlinear waveguides

    DOE Patents [OSTI]

    Findikoglu, Alp T.; Hahn, Sangkoo F.; Jia, Quanxi

    2004-06-22

    Dynamic time expansion or compression of a small-amplitude input signal generated with an initial scale is performed using a nonlinear waveguide. A nonlinear waveguide having a variable refractive index is connected to a bias voltage source having a bias signal amplitude that is large relative to the input signal to vary the reflective index and concomitant speed of propagation of the nonlinear waveguide and an electrical circuit for applying the small-amplitude signal and the large amplitude bias signal simultaneously to the nonlinear waveguide. The large amplitude bias signal with the input signal alters the speed of propagation of the small-amplitude signal with time in the nonlinear waveguide to expand or contract the initial time scale of the small-amplitude input signal.

  3. Dynamic Time Expansion and Compression Using Nonlinear Waveguides

    DOE Patents [OSTI]

    Findikoglu, Alp T.; Hahn, Sangkoo F.; Jia, Quanxi

    2004-06-22

    Dynamic time expansion or compression of a small amplitude input signal generated with an initial scale is performed using a nonlinear waveguide. A nonlinear waveguide having a variable refractive index is connected to a bias voltage source having a bias signal amplitude that is large relative to the input signal to vary the reflective index and concomitant speed of propagation of the nonlinear waveguide and an electrical circuit for applying the small amplitude signal and the large amplitude bias signal simultaneously to the nonlinear waveguide. The large amplitude bias signal with the input signal alters the speed of propagation of the small-amplitude signal with time in the nonlinear waveguide to expand or contract the initial time scale of the small-amplitude input signal.

  4. Linear-array ultrasonic waveguide transducer for under sodium viewing.

    SciTech Connect (OSTI)

    Sheen, S. H.; Chien, H. T.; Wang, K.; Lawrence, W. P.; Engel, D.; Nuclear Engineering Division

    2010-09-01

    In this report, we first present the basic design of a low-noise waveguide and its performance followed by a review of the array transducer technology. The report then presents the concept and basic designs of arrayed waveguide transducers that can apply to under-sodium viewing for in-service inspection of fast reactors. Depending on applications, the basic waveguide arrays consist of designs for sideway and downward viewing. For each viewing application, two array geometries, linear and circular, are included in design analysis. Methods to scan a 2-D target using a linear array waveguide transducer are discussed. Future plan to develop a laboratory array waveguide prototype is also presented.

  5. Nonlinear optical coupler using a doped optical waveguide

    DOE Patents [OSTI]

    Pantell, Richard H.; Sadowski, Robert W.; Digonnet, Michel J. F.; Shaw, Herbert J.

    1994-01-01

    An optical mode coupling apparatus includes an Erbium-doped optical waveguide in which an optical signal at a signal wavelength propagates in a first spatial propagation mode and a second spatial propagation mode of the waveguide. The optical signal propagating in the waveguide has a beat length. The coupling apparatus includes a pump source of perturbational light signal at a perturbational wavelength that propagates in the waveguide in the first spatial propagation mode. The perturbational signal has a sufficient intensity distribution in the waveguide that it causes a perturbation of the effective refractive index of the first spatial propagation mode of the waveguide in accordance with the optical Kerr effect. The perturbation of the effective refractive index of the first spatial propagation mode of the optical waveguide causes a change in the differential phase delay in the optical signal propagating in the first and second spatial propagation modes. The change in the differential phase delay is detected as a change in the intensity distribution between two lobes of the optical intensity distribution pattern of an output signal. The perturbational light signal can be selectively enabled and disabled to selectively change the intensity distribution in the two lobes of the optical intensity distribution pattern.

  6. Nonlinear waves in an array of zigzag waveguides with alternating positive and negative refractive indices

    SciTech Connect (OSTI)

    Kazantseva, E V; Maimistov, A I

    2013-09-30

    Interaction of coupled waves propagating in a system of waveguides with alternating positive and negative refractive indices is studied theoretically. The zigzag configuration of the waveguides in the array allows communication not only between the nearest neighbours, but also with the waveguides beyond them. It is shown that the spectrum of linear waves in such a waveguide system has a bandgap. Partial solutions are found to the system of coupled waves corresponding to a stationary electromagnetic field pulse that propagates along the array of tunnel-coupled waveguides as a whole. Investigation of the interaction of nonlinear solitary waves has demonstrated numerically the stability of their relatively weak disturbances and collisions with each other. (nanogradient dielectric coatings and metamaterials)

  7. A nonlinear analysis of the terahertz serpentine waveguide traveling-wave amplifier

    SciTech Connect (OSTI)

    Li, Ke Cao, Miaomiao; Liu, Wenxin Wang, Yong

    2015-04-15

    A nonlinear model for the numerical simulation of terahertz serpentine waveguide traveling-wave tube (SW-TWT) is described. In this model, the electromagnetic wave transmission in the SW is represented as an infinite set of space harmonics to interact with an electron beam. Analytical expressions for axial electric fields in axisymmetric interaction gaps of SW-TWTs are derived and compared with the results from CST simulation. The continuous beam is treated as discrete macro-particles with different initial phases. The beam-tunnel field equations, space-charge field equations, and motion equations are combined to solve the beam-wave interaction. The influence of backward wave and relativistic effect is also considered in the series of equations. The nonlinear model is used to design a 340 GHz SW-TWT. Several favorable comparisons of model predictions with results from a 3-D Particle-in-cell simulation code CHIPIC are presented, in which the output power versus beam voltage and interaction periods are illustrated. The relative error of the predicted output power is less than 15% in the 3 dB bandwidth and the relative error of the saturated length is less than 8%.The results show that the 1-D nonlinear analysis model is appropriate to solve the terahertz SW-TWT operation characteristics.

  8. Observation of nonlinear bands in near-field scanning optical microscopy of a photonic-crystal waveguide

    SciTech Connect (OSTI)

    Singh, A.; Huisman, S. R.; Ctistis, G. Mosk, A. P.; Pinkse, P. W. H.; Korterik, J. P.; Herek, J. L.

    2015-01-21

    We have measured the photonic bandstructure of GaAs photonic-crystal waveguides with high resolution in energy as well as in momentum using near-field scanning optical microscopy. Intriguingly, we observe additional bands that are not predicted by eigenmode solvers, as was recently demonstrated by Huisman et al. [Phys. Rev. B 86, 155154 (2012)]. We study the presence of these additional bands by performing measurements of these bands while varying the incident light power, revealing a non-linear power dependence. Here, we demonstrate experimentally and theoretically that the observed additional bands are caused by a waveguide-specific near-field tip effect not previously reported, which can significantly phase-modulate the detected field.

  9. Graphene-doped polymer nanofibers for low-threshold nonlinear optical waveguiding

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

    Meng, Chao; Yu, Shao-Liang; Wang, Hong -Qing; Cao, Yue; Tong, Li -Min; Liu, Wei -Tao; Shen, Yuen -Ron

    2015-11-06

    Graphene-doped polymer nanofibers are fabricated by taper drawing of solvated polyvinyl alcohol doped with liquid-phase exfoliated graphene flakes. Nanofibers drawn this way typically have diameters measured in hundreds of nanometers and lengths in tens of millimeters; they show excellent uniformity and surface smoothness for optical waveguiding. Owing to their tightly confined waveguiding behavior, light–matter interaction in these subwavelength-diameter nanofibers is significantly enhanced. Using approximately 1350-nm-wavelength femto-second pulses, we demonstrate saturable absorption behavior in these nanofibers with a saturation threshold down to 0.25 pJ pulse-1 (peak power ~1.3 W). Additionally, using 1064-nm-wavelength nanosecond pulses as switching light, we show all-optical modulationmore » of a 1550-nm-wavelength signal light guided along a single nanofiber with a switching peak power of ~3.2 W.« less

  10. Graphene-doped polymer nanofibers for low-threshold nonlinear optical waveguiding

    SciTech Connect (OSTI)

    Meng, Chao; Yu, Shao-Liang; Wang, Hong -Qing; Cao, Yue; Tong, Li -Min; Liu, Wei -Tao; Shen, Yuen -Ron

    2015-11-06

    Graphene-doped polymer nanofibers are fabricated by taper drawing of solvated polyvinyl alcohol doped with liquid-phase exfoliated graphene flakes. Nanofibers drawn this way typically have diameters measured in hundreds of nanometers and lengths in tens of millimeters; they show excellent uniformity and surface smoothness for optical waveguiding. Owing to their tightly confined waveguiding behavior, light–matter interaction in these subwavelength-diameter nanofibers is significantly enhanced. Using approximately 1350-nm-wavelength femto-second pulses, we demonstrate saturable absorption behavior in these nanofibers with a saturation threshold down to 0.25 pJ pulse-1 (peak power ~1.3 W). Additionally, using 1064-nm-wavelength nanosecond pulses as switching light, we show all-optical modulation of a 1550-nm-wavelength signal light guided along a single nanofiber with a switching peak power of ~3.2 W.

  11. Electrodynamic properties of coplanar waveguides made from high-temperature superconducting YBa{sub 2}Cu{sub 3}O{sub 7{minus}{delta}} electrodes on nonlinear dielectric SrTiO{sub 3} substrates

    SciTech Connect (OSTI)

    Findikoglu, A.T.; Reagor, D.W.; Rasmussen, K.O.; Bishop, A.R.; Gro Jia, Q.X.; Fan, Y.; Kwon, C.; Ostrovsky, L.A.

    1999-08-01

    We present a comprehensive study of broadband (0{endash}2 GHz) electrodynamic properties of coplanar waveguides made from high-temperature superconducting thin-film YBa{sub 2}Cu{sub 3}O{sub 7{minus}{delta}} electrodes on nonlinear dielectric single-crystal SrTiO{sub 3} substrates. The waveguides exhibit strong dielectric nonlinearities, in addition to temperature-, dc-bias-, and frequency-dependent dissipation and refractive index. By using parameters determined from small-signal (linear) transmission characteristics of the waveguides as a function of dc bias, we develop a model equation that successfully predicts and describes large-signal (nonlinear) behavior. {copyright} {ital 1999 American Institute of Physics.}

  12. Guided wave methods and apparatus for nonlinear frequency generation

    DOE Patents [OSTI]

    Durfee, III, Charles G.; Rundquist, Andrew; Kapteyn, Henry C.; Murnane, Margaret M.

    2000-01-01

    Methods and apparatus are disclosed for the nonlinear generation of sum and difference frequencies of electromagnetic radiation propagating in a nonlinear material. A waveguide having a waveguide cavity contains the nonlinear material. Phase matching of the nonlinear generation is obtained by adjusting a waveguide propagation constant, the refractive index of the nonlinear material, or the waveguide mode in which the radiation propagates. Phase matching can be achieved even in isotropic nonlinear materials. A short-wavelength radiation source uses phase-matched nonlinear generation in a waveguide to produce high harmonics of a pulsed laser.

  13. LOADED WAVEGUIDES

    DOE Patents [OSTI]

    Mullett, L.B.; Loach, B.G.; Adams, G.L.

    1958-06-24

    >Loaded waveguides are described for the propagation of electromagnetic waves with reduced phase velocities. A rectangular waveguide is dimensioned so as to cut-off the simple H/sub 01/ mode at the operating frequency. The waveguide is capacitance loaded, so as to reduce the phase velocity of the transmitted wave, by connecting an electrical conductor between directly opposite points in the major median plane on the narrower pair of waveguide walls. This conductor may take a corrugated shape or be an aperature member, the important factor being that the electrical length of the conductor is greater than one-half wavelength at the operating frequency. Prepared for the Second U.N. International ConferThe importance of nuclear standards is duscussed. A brief review of the international callaboration in this field is given. The proposal is made to let the International Organization for Standardization (ISO) coordinate the efforts from other groups. (W.D.M.)

  14. Parabolic tapers for overmoded waveguides

    DOE Patents [OSTI]

    Doane, J.L.

    1983-11-25

    A waveguide taper with a parabolic profile, in which the distance along the taper axis varies as the square of the tapered dimension, provides less mode conversion than equal length linear tapers and is easier to fabricate than other non-linear tapers.

  15. Nonlinear

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

    magnetohydrodynamics of pulsed parallel current drive in reversed-field pinches J. M. Reynolds, a͒ C. R. Sovinec, and S. C. Prager University of Wisconsin-Madison, Madison, Wisconsin 53706, USA ͑Received 28 April 2008; accepted 9 May 2008; published online 27 June 2008͒ Nonlinear simulation with a simple resistive magnetohydrodynamics model is used to investigate the stabilization of magnetic fluctuations in reversed-field pinch plasmas subject to pulsed-parallel current drive. Numerical

  16. Waveguide gas laser

    SciTech Connect (OSTI)

    Zedong, C.

    1982-05-01

    Waveguide gas lasers are described. Transmission loss of hollow tube light waveguides, coupling loss, the calculation of output power, and the width of the oscillation belt are discussed. The structure of a waveguide CO/sub 2/ laser is described.

  17. Optical analogue of relativistic Dirac solitons in binary waveguide arrays

    SciTech Connect (OSTI)

    Tran, Truong X.; Longhi, Stefano; Biancalana, Fabio; School of Engineering and Physical Sciences, Heriot-Watt University, EH14 4AS Edinburgh

    2014-01-15

    We study analytically and numerically an optical analogue of Dirac solitons in binary waveguide arrays in the presence of Kerr nonlinearity. Pseudo-relativistic soliton solutions of the coupled-mode equations describing dynamics in the array are analytically derived. We demonstrate that with the found soliton solutions, the coupled mode equations can be converted into the nonlinear relativistic 1D Dirac equation. This paves the way for using binary waveguide arrays as a classical simulator of quantum nonlinear effects arising from the Dirac equation, something that is thought to be impossible to achieve in conventional (i.e. linear) quantum field theory. -- Highlights: •An optical analogue of Dirac solitons in nonlinear binary waveguide arrays is suggested. •Analytical solutions to pseudo-relativistic solitons are presented. •A correspondence of optical coupled-mode equations with the nonlinear relativistic Dirac equation is established.

  18. January 2013 Most Viewed Documents for Physics | OSTI, US Dept...

    Office of Scientific and Technical Information (OSTI)

    Dynamic Time Expansion and Compression Using Nonlinear Waveguides Findikoglu, Alp T.; ... replaceable unit transport and handling systems Hall, T B Heating Distributions in the ...

  19. Waveguide disturbance detection method

    DOE Patents [OSTI]

    Korneev, Valeri A.; Nihei, Kurt T.; Myer, Larry R.

    2000-01-01

    A method for detection of a disturbance in a waveguide comprising transmitting a wavefield having symmetric and antisymmetric components from a horizontally and/or vertically polarized source and/or pressure source disposed symmetrically with respect to the longitudinal central axis of the waveguide at one end of the waveguide, recording the horizontal and/or vertical component or a pressure of the wavefield with a vertical array of receivers disposed at the opposite end of the waveguide, separating the wavenumber transform of the wavefield into the symmetric and antisymmetric components, integrating the symmetric and antisymmetric components over a broad frequency range, and comparing the magnitude of the symmetric components and the antisymmetric components to an expected magnitude for the symmetric components and the antisymmetric components for a waveguide of uniform thickness and properties thereby determining whether or not a disturbance is present inside the waveguide.

  20. Broad band waveguide spectrometer

    DOE Patents [OSTI]

    Goldman, Don S.

    1995-01-01

    A spectrometer for analyzing a sample of material utilizing a broad band source of electromagnetic radiation and a detector. The spectrometer employs a waveguide possessing an entry and an exit for the electromagnetic radiation emanating from the source. The waveguide further includes a surface between the entry and exit portions which permits interaction between the electromagnetic radiation passing through the wave guide and a sample material. A tapered portion forms a part of the entry of the wave guide and couples the electromagnetic radiation emanating from the source to the waveguide. The electromagnetic radiation passing from the exit of the waveguide is captured and directed to a detector for analysis.

  1. Birefringent corrugated waveguide

    DOE Patents [OSTI]

    Moeller, Charles P.

    1990-01-01

    A corrugated waveguide having a circular bore and noncircularly symmetric corrugations, and preferably elliptical corrugations, provides birefringence for rotation of polarization in the HE.sub.11 mode. The corrugated waveguide may be fabricated by cutting circular grooves on a lathe in a cylindrical tube or rod of aluminum of a diameter suitable for the bore of the waveguide, and then cutting an approximation to ellipses for the corrugations using a cutting radius R.sub.0 from the bore axis that is greater than the bore radius, and then making two circular cuts using a radius R.sub.1 less than R.sub.0 at centers +b and -b from the axis of the waveguide bore. Alternatively, stock for the mandrel may be formed with an elliptical transverse cross section, and then only the circular grooves need be cut on a lathe, leaving elliptical corrugations between the grooves. In either case, the mandrel is first electroplated and then dissolved leaving a corrugated waveguide with noncircularly symmetric corrugations. A transition waveguide is used that gradually varies from circular to elliptical corrugations to couple a circularly corrugated waveguide to an elliptically corrugated waveguide.

  2. Zero-mode waveguides

    DOE Patents [OSTI]

    Levene, Michael J.; Korlach, Jonas; Turner, Stephen W.; Craighead, Harold G.; Webb, Watt W.

    2007-02-20

    The present invention is directed to a method and an apparatus for analysis of an analyte. The method involves providing a zero-mode waveguide which includes a cladding surrounding a core where the cladding is configured to preclude propagation of electromagnetic energy of a frequency less than a cutoff frequency longitudinally through the core of the zero-mode waveguide. The analyte is positioned in the core of the zero-mode waveguide and is then subjected, in the core of the zero-mode waveguide, to activating electromagnetic radiation of a frequency less than the cut-off frequency under conditions effective to permit analysis of the analyte in an effective observation volume which is more compact than if the analysis were carried out in the absence of the zero-mode waveguide.

  3. Nanocrystal waveguide (NOW) laser

    DOE Patents [OSTI]

    Simpson, John T.; Simpson, Marcus L.; Withrow, Stephen P.; White, Clark W.; Jaiswal, Supriya L.

    2005-02-08

    A solid state laser includes an optical waveguide and a laser cavity including at least one subwavelength mirror disposed in or on the optical waveguide. A plurality of photoluminescent nanocrystals are disposed in the laser cavity. The reflective subwavelength mirror can be a pair of subwavelength resonant gratings (SWG), a pair of photonic crystal structures (PC), or a distributed feedback structure. In the case of a pair of mirrors, a PC which is substantially transmissive at an operating wavelength of the laser can be disposed in the laser cavity between the subwavelength mirrors to improve the mode structure, coherence and overall efficiency of the laser. A method for forming a solid state laser includes the steps of providing an optical waveguide, creating a laser cavity in the optical waveguide by disposing at least one subwavelength mirror on or in the waveguide, and positioning a plurality of photoluminescent nanocrystals in the laser cavity.

  4. A bright PPKTP waveguide source of polarization entangled photons

    SciTech Connect (OSTI)

    Fanto, Michael; Tison, Christoper C.; Holwand, Gregory A; Preble, Dr. Stefan F; Alsing, Paul; Smith IV, Amos M

    2015-01-01

    The need for bright efficient sources of entangled photons has been a subject of tremendous research over the last decade. Researchers have been working to increase the brightness and purity to help overcome the spontaneous nature of the sources. Periodic poling has been implemented to allow for the use of crystals that would not normally satisfy the phase matching conditions. Utilizing periodic poling and single mode waveguide confinement of the pump field has yielded extremely large effective nonlinearities in sources easily producing millions of photon pairs. Here we will demonstrate these large nonlinearity effects in a periodically poled potassium titanyl phosphate (PPKTP) waveguide as well as characterizing the source purity.

  5. Compound semiconductor optical waveguide switch

    DOE Patents [OSTI]

    Spahn, Olga B.; Sullivan, Charles T.; Garcia, Ernest J.

    2003-06-10

    An optical waveguide switch is disclosed which is formed from III-V compound semiconductors and which has a moveable optical waveguide with a cantilevered portion that can be bent laterally by an integral electrostatic actuator to route an optical signal (i.e. light) between the moveable optical waveguide and one of a plurality of fixed optical waveguides. A plurality of optical waveguide switches can be formed on a common substrate and interconnected to form an optical switching network.

  6. Microfabricated bragg waveguide

    DOE Patents [OSTI]

    Fleming, James G.; Lin, Shawn-Yu; Hadley, G. Ronald

    2004-10-19

    A microfabricated Bragg waveguide of semiconductor-compatible material having a hollow core and a multilayer dielectric cladding can be fabricated by integrated circuit technologies. The microfabricated Bragg waveguide can comprise a hollow channel waveguide or a hollow fiber. The Bragg fiber can be fabricated by coating a sacrificial mandrel or mold with alternating layers of high- and low-refractive-index dielectric materials and then removing the mandrel or mold to leave a hollow tube with a multilayer dielectric cladding. The Bragg channel waveguide can be fabricated by forming a trench embedded in a substrate and coating the inner wall of the trench with a multilayer dielectric cladding. The thicknesses of the alternating layers can be selected to satisfy the condition for minimum radiation loss of the guided wave.

  7. Surface modification to waveguides

    DOE Patents [OSTI]

    Timberlake, John R.; Ruzic, David N.; Moore, Richard L.; Cohen, Samuel A.; Manos, Dennis M.

    1983-01-01

    A method of treating the interior surfaces of a waveguide to improve power transmission comprising the steps of mechanically polishing to remove surface protrusions; electropolishing to remove embedded particles; ultrasonically cleaning to remove any residue; coating the interior waveguide surfaces with an alkyd resin solution or electrophoretically depositing carbon lamp black suspended in an alkyd resin solution to form a 1.mu. to 5.mu. thick film; vacuum pyrolyzing the film to form a uniform adherent carbon coating.

  8. Surface modification to waveguides

    DOE Patents [OSTI]

    Timberlake, J.R.; Ruzic, D.N.; Moore, R.L.; Cohen, S.A.; Manos, D.M.

    1982-06-16

    A method is described for treating the interior surfaces of a waveguide to improve power transmission comprising the steps of mechanically polishing to remove surface protrusions; electropolishing to remove embedded particles; ultrasonically cleaning to remove any residue; coating the interior waveguide surfaces with an alkyd resin solution or electrophoretically depositing carbon lamp black suspended in an alkyd resin solution to form a 1..mu.. to 5..mu.. thick film; vacuum pyrolyzing the film to form a uniform adherent carbon coating.

  9. Higher-order Dirac solitons in binary waveguide arrays

    SciTech Connect (OSTI)

    Tran, Truong X.; Duong, Dũng C.

    2015-10-15

    We study optical analogues of higher-order Dirac solitons (HODSs) in binary waveguide arrays. Like higher-order solitons obtained from the well-known nonlinear Schrödinger equation governing the pulse propagation in an optical fiber, these HODSs have amplitude profiles which are numerically shown to be periodic over large propagation distances. At the same time, HODSs possess some unique features. Firstly, the period of a HODS depends on its order parameter. Secondly, the discrete nature in binary waveguide arrays imposes the upper limit on the order parameter of HODSs. Thirdly, the order parameter of HODSs can vary continuously in a certain range. - Highlights: • Higher-order Dirac solitons in nonlinear binary waveguide arrays are numerically demonstrated. • Amplitude profiles of higher-order Dirac solitons are periodic during propagation. • The period of higher-order Dirac solitons decreases when the soliton order increases.

  10. NOVEL SIGNAL PROCESSING WITH NONLINEAR TRANSMISSION LINES

    SciTech Connect (OSTI)

    D. REAGOR; ET AL

    2000-08-01

    Nonlinear dielectrics offer uniquely strong and tunable nonlinearities that make them attractive for current devices (for example, frequency-agile microwave filters) and for future signal-processing technologies. The goal of this project is to understand pulse propagation on nonlinear coplanar waveguide prototype devices. We have performed time-domain and frequency-domain experimental studies of simple waveguide structures and pursued a theoretical understanding of the propagation of signals on these nonlinear waveguides. To realistically assess the potential applications, we used a time-domain measurement and analysis technique developed during this project to perform a broadband electrodynamics characterization in terms of nonlinear, dispersive, and dissipative effects. We completed a comprehensive study of coplanar waveguides made from high-temperature superconducting thin-film YBa{sub 2}Cu{sub 3}O{sub 7{minus}{delta}} electrodes on nonlinear dielectric single-crystal SrTiO{sub 3} substrates. By using parameters determined from small-signal (linear) transmission characteristics of the waveguides, we develop a model equation that successfully predicts and describes large-signal (nonlinear) behavior.

  11. Optical waveguides in lithium niobate: Recent developments and applications

    SciTech Connect (OSTI)

    Bazzan, Marco Sada, Cinzia

    2015-12-15

    The state of the art of optical waveguide fabrication in lithium niobate is reviewed, with particular emphasis on new technologies and recent applications. The attention is mainly devoted to recently developed fabrication methods, such as femtosecond laser writing, ion implantation, and smart cut waveguides as well as to the realization of waveguides with tailored functionalities, such as photorefractive or domain engineered structures. More exotic systems, such as reconfigurable and photorefractive soliton waveguides, are also considered. Classical techniques, such as Ti in-diffusion and proton exchange, are cited and briefly reviewed as a reference standpoint to highlight the recent developments. In all cases, the application-oriented point of view is preferred, in order to provide the reader with an up-to date panorama of the vast possibilities offered by lithium niobate to integrated photonics.

  12. Gap soliton formation in a nonlinear anti-directional coupler

    SciTech Connect (OSTI)

    Ryzhov, M S; Maimistov, Andrei I

    2012-11-30

    We consider propagation of electromagnetic solitary waves in two tunnel-coupled waveguides. It is assumed that one of the waveguides is made of a positive-index dielectric, having a Kerr nonlinearity. The other waveguide is made of a linear optical metamaterial characterised by the so-called negative refraction. The gap soliton formation in such a system, which, as shown, has a threshold character, is studied numerically. (solitons)

  13. Aqueous carrier waveguide in a flow cytometer

    DOE Patents [OSTI]

    Mariella, Jr., Raymond P.; van den Engh, Gerrit; Northrup, M. Allen

    1995-01-01

    The liquid of a flow cytometer itself acts as an optical waveguide, thus transmitting the light to an optical filter/detector combination. This alternative apparatus and method for detecting scattered light in a flow cytometer is provided by a device which views and detects the light trapped within the optical waveguide formed by the flow stream. A fiber optic or other light collecting device is positioned within the flow stream. This provides enormous advantages over the standard light collection technique which uses a microscope objective. The signal-to-noise ratio is greatly increased over that for right-angle-scattered light collected by a microscope objective, and the alignment requirements are simplified.

  14. Aqueous carrier waveguide in a flow cytometer

    DOE Patents [OSTI]

    Mariella, R.P. Jr.; Engh, G. van den; Northrup, M.A.

    1995-12-12

    The liquid of a flow cytometer itself acts as an optical waveguide, thus transmitting the light to an optical filter/detector combination. This alternative apparatus and method for detecting scattered light in a flow cytometer is provided by a device which views and detects the light trapped within the optical waveguide formed by the flow stream. A fiber optic or other light collecting device is positioned within the flow stream. This provides enormous advantages over the standard light collection technique which uses a microscope objective. The signal-to-noise ratio is greatly increased over that for right-angle-scattered light collected by a microscope objective, and the alignment requirements are simplified. 6 figs.

  15. Experimental investigation of plasmofluidic waveguides

    SciTech Connect (OSTI)

    Ku, Bonwoo; Kwon, Min-Suk; Shin, Jin-Soo

    2015-11-16

    Plasmofluidic waveguides are based on guiding light which is strongly confined in fluid with the assistance of a surface plasmon polariton. To realize plasmofluidic waveguides, metal-insulator-silicon-insulator-metal (MISIM) waveguides, which are hybrid plasmonic waveguides fabricated using standard complementary metal-oxide-semiconductor technology, are employed. The insulator of the MISIM waveguide is removed to form 30-nm-wide channels, and they are filled with fluid. The plasmofluidic waveguide has a subwavelength-scale mode area since its mode is strongly confined in the fluid. The waveguides are experimentally characterized for different fluids. When the refractive index of the fluid is 1.440, the plasmofluidic waveguide with 190-nm-wide silicon has propagation loss of 0.46 dB/μm; the coupling loss between it and an ordinary silicon photonic waveguide is 1.79 dB. The propagation and coupling losses may be reduced if a few fabrication-induced imperfections are removed. The plasmofluidic waveguide may pave the way to a dynamically phase-tunable ultracompact device.

  16. January 2013 Most Viewed Documents for Physics | OSTI, US Dept of Energy

    Office of Scientific and Technical Information (OSTI)

    Office of Scientific and Technical Information January 2013 Most Viewed Documents for Physics Dynamic Time Expansion and Compression Using Nonlinear Waveguides Findikoglu, Alp T.; Hahn, Sangkoo F.; Jia, Quanxi Atmospheric PSF Interpolation for Weak Lensing in Short Exposure Imaging Data Chang, C.; Marshall, P.J.; Jernigan, J.G.; Peterson, J.R.; Kahn, S.M.; Gull, S.F.; AlSayyad, Y.; Ahmad, Z.; Bankert, J.; Bard, D.; Connolly, A.; Gibson, R.R.; Gilmore, K.; Grace, E.; Hannel, M.; Hodge, M.A.;

  17. Influence of ponderomotive force on the microwave and plasma interaction in an elliptical waveguide

    SciTech Connect (OSTI)

    Abdoli-Arani, A., E-mail: abdoliabbas@kashanu.ac.ir [Department of Photonics, Faculty of Physics, University of Kashan, Kashan, Islamic Republic of Iran (Iran, Islamic Republic of)

    2014-02-15

    The interaction effect of a high-power microwave with the plasma in an elliptical waveguide taking into account the ponderomotive force is presented. Here, we assume the fundamental mode that propagates in an evacuated elliptical waveguide and encounters a plasma, which is filled in another elliptical waveguide of the same size. Here, we consider a balance between the effects of ponderomotive force and the electron pressure and consider the plasma effect through its dielectric permittivity because the electron density distribution of the plasma is modified. The propagation of the mode is described by two nonlinear coupled differential equations obtained using the Maxwell's equations. These equations are solved numerically using fourth order Runge-Kutta method for the field amplitude of the microwave in the waveguide considering the waveguide to be made up of a perfect conductor and filled with homogeneous plasma density distribution. The effects of the electron temperature, the microwave filed, and the frequency on the perturbed density profile are studied.

  18. Microwave waveguide manifold and method

    DOE Patents [OSTI]

    Staehlin, John H.

    1987-01-01

    A controllably electrically coupled, physically intersecting plural waveguide manifold assembly wherein the intersecting waveguide elements are fabricated in integral unitary relationship from a single piece of metal in order to avoid the inaccuracies and difficult-to-control fabrication steps associated with uniting separate waveguide elements into a unitary structure. An X-band aluminum airborne radar manifold example is disclosed, along with a fabrication sequence for the manifold and the electrical energy communicating apertures joining the manifold elements.

  19. Folded waveguide coupler

    DOE Patents [OSTI]

    Owens, Thomas L.

    1988-03-01

    A resonant cavity waveguide coupler for ICRH of a magnetically confined plasma. The coupler consists of a series of inter-leaved metallic vanes disposed withn an enclosure analogous to a very wide, simple rectangular waveguide that has been "folded" several times. At the mouth of the coupler, a polarizing plate is provided which has coupling apertures aligned with selected folds of the waveguide through which rf waves are launched with magnetic fields of the waves aligned in parallel with the magnetic fields confining the plasma being heated to provide coupling to the fast magnetosonic wave within the plasma in the frequency usage of from about 50-200 mHz. A shorting plate terminates the back of the cavity at a distance approximately equal to one-half the guide wavelength from the mouth of the coupler to ensure that the electric field of the waves launched through the polarizing plate apertures are small while the magnetic field is near a maximum. Power is fed into the coupler folded cavity by means of an input coaxial line feed arrangement at a point which provides an impedance match between the cavity and the coaxial input line.

  20. Scintillator Waveguide For Sensing Radiation

    DOE Patents [OSTI]

    Bliss, Mary; Craig, Richard A.; Reeder; Paul L.

    2003-04-22

    The present invention is an apparatus for detecting ionizing radiation, having: a waveguide having a first end and a second end, the waveguide formed of a scintillator material wherein the therapeutic ionizing radiation isotropically generates scintillation light signals within the waveguide. This apparatus provides a measure of radiation dose. The apparatus may be modified to permit making a measure of location of radiation dose. Specifically, the scintillation material is segmented into a plurality of segments; and a connecting cable for each of the plurality of segments is used for conducting scintillation signals to a scintillation detector.

  1. Waveguides for performing enzymatic reactions

    DOE Patents [OSTI]

    Levene; Michael J. , Korlach; Jonas , Turner; Stephen W. , Craighead; Harold G. , Webb; Watt W.

    2007-11-06

    The present invention is directed to a method and an apparatus for analysis of an analyte. The method involves providing a zero-mode waveguide which includes a cladding surrounding a core where the cladding is configured to preclude propagation of electromagnetic energy of a frequency less than a cutoff frequency longitudinally through the core of the zero-mode waveguide. The analyte is positioned in the core of the zero-mode waveguide and is then subjected, in the core of the zero-mode wave guide, to activating electromagnetic radiation of a frequency less than the cut-off frequency under conditions effective to permit analysis of the analyte in an effective observation volume which is more compact than if the analysis were carried out in the absence of the zero-mode waveguide.

  2. Temporal waveguides for optical pulses

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

    Plansinis, Brent W.; Donaldson, William R.; Agrawal, Govind P.

    2016-05-12

    Here we discuss, temporal total internal reflection (TIR), in analogy to the conventional TIR of an optical beam at a dielectric interface, is the total reflection of an optical pulse inside a dispersive medium at a temporal boundary across which the refractive index changes. A pair of such boundaries separated in time acts as the temporal analog of planar dielectric waveguides. We study the propagation of optical pulses inside such temporal waveguides, both analytically and numerically, and show that the waveguide supports a finite number of temporal modes. We also discuss how a single-mode temporal waveguide can be created inmore » practice. In contrast with the spatial case, the confinement can occur even when the central region has a lower refractive index.« less

  3. Simplified flangeless unisex waveguide coupler assembly

    DOE Patents [OSTI]

    Michelangelo, Dimartino; Moeller, Charles P.

    1993-01-01

    A unisex coupler assembly is disclosed capable of providing a leak tight coupling for waveguides with axial alignment of the waveguides and rotational capability. The sealing means of the coupler assembly are not exposed to RF energy, and the coupler assembly does not require the provision of external flanges on the waveguides. In a preferred embodiment, O ring seals are not used and the coupler assembly is, therefore, bakeable at a temperature up to about 150.degree. C. The coupler assembly comprises a split collar which clamps around the waveguides and a second collar which fastens to the split collar. The split collar contains an inner annular groove. Each of the waveguides is provided with an external annular groove which receives a retaining ring. The split collar is clamped around one of the waveguides with the inner annular groove of the split collar engaging the retaining ring carried in the external annular groove in the waveguide. The second collar is then slipped over the second waveguide behind the annular groove and retaining ring therein and the second collar is coaxially secured by fastening means to the split collar to draw the respective waveguides together by coaxial force exerted by the second collar against the retaining ring on the second waveguide. A sealing ring is placed against an external sealing surface at a reduced external diameter end formed on one waveguide to sealingly engage a corresponding sealing surface on the other waveguide as the waveguides are urged toward each other.

  4. Simplified flangeless unisex waveguide coupler assembly

    DOE Patents [OSTI]

    Michelangelo, D.; Moeller, C.P.

    1993-05-04

    A unisex coupler assembly is disclosed capable of providing a leak tight coupling for waveguides with axial alignment of the waveguides and rotational capability. The sealing means of the coupler assembly are not exposed to RF energy, and the coupler assembly does not require the provision of external flanges on the waveguides. In a preferred embodiment, O ring seals are not used and the coupler assembly is, therefore, bakeable at a temperature up to about 150 C. The coupler assembly comprises a split collar which clamps around the waveguides and a second collar which fastens to the split collar. The split collar contains an inner annular groove. Each of the waveguides is provided with an external annular groove which receives a retaining ring. The split collar is clamped around one of the waveguides with the inner annular groove of the split collar engaging the retaining ring carried in the external annular groove in the waveguide. The second collar is then slipped over the second waveguide behind the annular groove and retaining ring therein and the second collar is coaxially secured by fastening means to the split collar to draw the respective waveguides together by coaxial force exerted by the second collar against the retaining ring on the second waveguide. A sealing ring is placed against an external sealing surface at a reduced external diameter end formed on one waveguide to sealingly engage a corresponding sealing surface on the other waveguide as the waveguides are urged toward each other.

  5. Integration of a waveguide self-electrooptic effect device and a vertically coupled interconnect waveguide

    DOE Patents [OSTI]

    Vawter, G. Allen

    2008-02-26

    A self-electrooptic effect device ("SEED") is integrated with waveguide interconnects through the use of vertical directional couplers. Light initially propagating in the interconnect waveguide is vertically coupled to the active waveguide layer of the SEED and, if the SEED is in the transparent state, the light is coupled back to the interconnect waveguide.

  6. Optical panel system including stackable waveguides

    DOE Patents [OSTI]

    DeSanto, Leonard; Veligdan, James T.

    2007-03-06

    An optical panel system including stackable waveguides is provided. The optical panel system displays a projected light image and comprises a plurality of planar optical waveguides in a stacked state. The optical panel system further comprises a support system that aligns and supports the waveguides in the stacked state. In one embodiment, the support system comprises at least one rod, wherein each waveguide contains at least one hole, and wherein each rod is positioned through a corresponding hole in each waveguide. In another embodiment, the support system comprises at least two opposing edge structures having the waveguides positioned therebetween, wherein each opposing edge structure contains a mating surface, wherein opposite edges of each waveguide contain mating surfaces which are complementary to the mating surfaces of the opposing edge structures, and wherein each mating surface of the opposing edge structures engages a corresponding complementary mating surface of the opposite edges of each waveguide.

  7. Optical panel system including stackable waveguides

    DOE Patents [OSTI]

    DeSanto, Leonard; Veligdan, James T.

    2007-11-20

    An optical panel system including stackable waveguides is provided. The optical panel system displays a projected light image and comprises a plurality of planar optical waveguides in a stacked state. The optical panel system further comprises a support system that aligns and supports the waveguides in the stacked state. In one embodiment, the support system comprises at least one rod, wherein each waveguide contains at least one hole, and wherein each rod is positioned through a corresponding hole in each waveguide. In another embodiment, the support system comprises at least two opposing edge structures having the waveguides positioned therebetween, wherein each opposing edge structure contains a mating surface, wherein opposite edges of each waveguide contain mating surfaces which are complementary to the mating surfaces of the opposing edge structures, and wherein each mating surface of the opposing edge structures engages a corresponding complementary mating surface of the opposite edges of each waveguide.

  8. Ultranarrow linewidth waveguide excimer lasers

    SciTech Connect (OSTI)

    Christensen, C.P. ); Feldman, B.J.; Huston, A.

    1989-09-01

    We have constructed a single longitudinal mode XeCl laser using microwave discharge waveguide laser technology. The pulse duration, repetition rate, and simplicity of construction associated with waveguide excimer lasers lend this system unique capabilities and a broad utility for interfacing with other excimer devices. The coherence length of the laser emission has been found to be {similar to}6 m with a corresponding bandwidth of {l brace}22 MHz that is near the transform limit. The laser has been used to demonstrate pulsed UV Doppler velocity measurement in a simple homodyne configuration.

  9. Non-degenerate two-photon absorption in silicon waveguides: Analytical and experimental study

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

    Zhang, Yanbing; Husko, Chad; Lefrancois, Simon; Rey, Isabella H.; Krauss, Thomas F.; Schrder, Jochen; Eggleton, Benjamin J.

    2015-06-22

    We theoretically and experimentally investigate the nonlinear evolution of two optical pulses in a silicon waveguide. We provide an analytic solution for the weak probe wave undergoing non-degenerate two-photon absorption (TPA) from the strong pump. At larger pump intensities, we employ a numerical solution to study the interplay between TPA and photo-generated free carriers. We develop a simple and powerful approach to extract and separate out the distinct loss contributions of TPA and free-carrier absorption from readily available experimental data. Our analysis accounts accurately for experimental results in silicon photonic crystal waveguides.

  10. Non-degenerate two-photon absorption in silicon waveguides. Analytical and experimental study

    SciTech Connect (OSTI)

    Zhang, Yanbing; Husko, Chad; Lefrancois, Simon; Rey, Isabella H.; Krauss, Thomas F.; Schröder, Jochen; Eggleton, Benjamin J.

    2015-06-22

    We theoretically and experimentally investigate the nonlinear evolution of two optical pulses in a silicon waveguide. We provide an analytic solution for the weak probe wave undergoing non-degenerate two-photon absorption (TPA) from the strong pump. At larger pump intensities, we employ a numerical solution to study the interplay between TPA and photo-generated free carriers. We develop a simple and powerful approach to extract and separate out the distinct loss contributions of TPA and free-carrier absorption from readily available experimental data. Our analysis accounts accurately for experimental results in silicon photonic crystal waveguides.

  11. Enhanced four-wave mixing in graphene-silicon slow-light photonic crystal waveguides

    SciTech Connect (OSTI)

    Zhou, Hao E-mail: tg2342@columbia.edu; Gu, Tingyi E-mail: tg2342@columbia.edu McMillan, James F.; Wong, Chee Wei E-mail: tg2342@columbia.edu; Petrone, Nicholas; Zande, Arend van der; Hone, James C.; Yu, Mingbin; Lo, Guoqiang; Kwong, Dim-Lee; Feng, Guoying; Zhou, Shouhuan

    2014-09-01

    We demonstrate the enhanced four-wave mixing of monolayer graphene on slow-light silicon photonic crystal waveguides. 200-μm interaction length, a four-wave mixing conversion efficiency of −23 dB is achieved in the graphene-silicon slow-light hybrid, with an enhanced 3-dB conversion bandwidth of about 17 nm. Our measurements match well with nonlinear coupled-mode theory simulations based on the measured waveguide dispersion, and provide an effective way for all-optical signal processing in chip-scale integrated optics.

  12. Dynamic Time Expansion and Compression Using Nonlinear Waveguides...

    Office of Scientific and Technical Information (OSTI)

    Country of Publication: United States Language: English Subject: 71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; AMPLITUDES; COMPRESSION; REFRACTIVE INDEX; VELOCITY; ...

  13. Wideband unbalanced waveguide power dividers and combiners

    DOE Patents [OSTI]

    Halligan, Matthew; McDonald, Jacob Jeremiah; Strassner, II, Bernd H.

    2016-05-17

    The various technologies presented herein relate to waveguide dividers and waveguide combiners for application in radar systems, wireless communications, etc. Waveguide dividers-combiners can be manufactured in accordance with custom dimensions, as well as in accordance with waveguide standards such that the input and output ports are of a defined dimension and have a common impedance. Various embodiments are presented which can incorporate one or more septum(s), one or more pairs of septums, an iris, an input matching region, a notch located on the input waveguide arm, waveguide arms having stepped transformer regions, etc. The various divider configurations presented herein can be utilized in high fractional bandwidth applications, e.g., a fractional bandwidth of about 30%, and RF applications in the Ka frequency band (e.g., 26.5-40 GHz).

  14. Optical fiber having wave-guiding rings

    DOE Patents [OSTI]

    Messerly, Michael J.; Dawson, Jay W.; Beach, Raymond J.; Barty, Christopher P. J.

    2011-03-15

    A waveguide includes a cladding region that has a refractive index that is substantially uniform and surrounds a wave-guiding region that has an average index that is close to the index of the cladding. The wave-guiding region also contains a thin ring or series of rings that have an index or indices that differ significantly from the index of the cladding. The ring or rings enable the structure to guide light.

  15. RF window assembly comprising a ceramic disk disposed within a cylindrical waveguide which is connected to rectangular waveguides through elliptical joints

    DOE Patents [OSTI]

    Tantawi, Sami G.; Dolgashev, Valery A.; Yeremian, Anahid D.

    2016-03-15

    A high-power microwave RF window is provided that includes a cylindrical waveguide, where the cylindrical waveguide includes a ceramic disk concentrically housed in a central region of the cylindrical waveguide, a first rectangular waveguide, where the first rectangular waveguide is connected by a first elliptical joint to a proximal end of the cylindrical waveguide, and a second rectangular waveguide, where the second rectangular waveguide is connected by a second elliptical joint to a distal end of the cylindrical waveguide.

  16. Planar Optical Waveguide Coupler Transformers for High-Power...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Planar Optical Waveguide Coupler Transformers for High-Power Solar Enegy Collection and Transmission Planar Optical Waveguide Coupler Transformers for High-Power Solar Enegy ...

  17. Dynamics of optical pulses in waveguides with a large self-steepening parameter

    SciTech Connect (OSTI)

    Zhuravlev, V M; Zolotovskii, I O; Korobko, D A; Fotiadi, A A

    2013-11-30

    We study the dynamics of a high-energy laser pulse in dispersive optical media with large values of self-steepening. We consider the formation of soliton-like peaks at the front of the envelope in such media with anomalous dispersion. We show the possibility of realisation of a medium based on a photonic crystal waveguide with a very large absolute value of the self-steepening parameter in a certain frequency range. (nonlinear optical phenomena)

  18. Free-carrier-induced soliton fission unveiled by in situ measurements in nanophotonic waveguides

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

    Husko, Chad; Wulf, Matthias; Lefrancois, Simon; Combrié, Sylvain; Lehoucq, Gaëlle; De Rossi, Alfredo; Eggleton, Benjamin J.; Kuipers, L.

    2016-04-15

    Solitons are localized waves formed by a balance of focusing and defocusing effects. These nonlinear waves exist in diverse forms of matter yet exhibit similar properties including stability, periodic recurrence and particle-like trajectories. One important property is soliton fission, a process by which an energetic higher-order soliton breaks apart due to dispersive or nonlinear perturbations. Here we demonstrate through both experiment and theory that nonlinear photocarrier generation can induce soliton fission. Using near-field measurements, we directly observe the nonlinear spatial and temporal evolution of optical pulses in situ in a nanophotonic semiconductor waveguide. We develop an analytic formalism describing themore » free-carrier dispersion (FCD) perturbation and show the experiment exceeds the minimum threshold by an order of magnitude. We confirm these observations with a numerical nonlinear Schrodinger equation model. Finally, these results provide a fundamental explanation and physical scaling of optical pulse evolution in free-carrier media and could enable improved supercontinuum sources in gas based and integrated semiconductor waveguides.« less

  19. Ultralow loss cavities and waveguides scattering loss cancellation

    DOE Patents [OSTI]

    Rakich, Peter T

    2014-01-07

    A waveguide system includes a first waveguide having surface roughness along at least one surface and a second waveguide substantially identical to the first waveguide and having substantially identical surface roughness along a corresponding side. The first and second waveguides are separated from each other by a predermined distance and are configured to receive respective first and second light signals having antisymmetric modes. The predetermined distance between the first and second waveguide tends to cause cancellation of at least far-field polarization radiation emanating from the first and second waveguides and resulting from surface roughness.

  20. Waveguide device and method for making same

    DOE Patents [OSTI]

    Forman, Michael A. (San Francisco, CA)

    2007-08-14

    A monolithic micromachined waveguide device or devices with low-loss, high-power handling, and near-optical frequency ranges is set forth. The waveguide and integrated devices are capable of transmitting near-optical frequencies due to optical-quality sidewall roughness. The device or devices are fabricated in parallel, may be mass produced using a LIGA manufacturing process, and may include a passive component such as a diplexer and/or an active capping layer capable of particularized signal processing of the waveforms propagated by the waveguide.

  1. Method of making a scintillator waveguide

    DOE Patents [OSTI]

    Bliss, Mary; Craig, Richard A.; Reeder, Paul L.

    2000-01-01

    The present invention is an apparatus for detecting ionizing radiation, having: a waveguide having a first end and a second end, the waveguide formed of a scintillator material wherein the therapeutic ionizing radiation isotropically generates scintillation light signals within the waveguide. This apparatus provides a measure of radiation dose. The apparatus may be modified to permit making a measure of location of radiation dose. Specifically, the scintillation material is segmented into a plurality of segments; and a connecting cable for each of the plurality of segments is used for conducting scintillation signals to a scintillation detector.

  2. Waveguide-based optical chemical sensor

    DOE Patents [OSTI]

    Grace, Karen M.; Swanson, Basil I.; Honkanen, Seppo

    2007-03-13

    The invention provides an apparatus and method for highly selective and sensitive chemical sensing. Two modes of laser light are transmitted through a waveguide, refracted by a thin film host reagent coating on the waveguide, and analyzed in a phase sensitive detector for changes in effective refractive index. Sensor specificity is based on the particular species selective thin films of host reagents which are attached to the surface of the planar optical waveguide. The thin film of host reagents refracts laser light at different refractive indices according to what species are forming inclusion complexes with the host reagents.

  3. Waveguides having patterned, flattened modes

    DOE Patents [OSTI]

    Messerly, Michael J; Pax, Paul H; Dawson, Jay W

    2015-11-05

    Field-flattening strands may be added to and arbitrarily positioned within a field-flattening shell to create a waveguide that supports a patterned, flattened mode. Patterning does not alter the effective index or flattened nature of the mode, but does alter the characteristics of other modes. Compared to a telecom fiber, a hexagonal pattern of strands allows for a three-fold increase in the flattened mode's area without reducing the separation between its effective index and that of its bend-coupled mode. Hexagonal strand and shell elements prove to be a reasonable approximation, and, thus, to be of practical benefit vis-a-vis fabrication, to those of circular cross section. Patterned flattened modes offer a new and valuable path to power scaling.

  4. Waveguides having patterned, flattened modes

    DOE Patents [OSTI]

    Messerly, Michael J.; Pax, Paul H.; Dawson, Jay W.

    2015-10-27

    Field-flattening strands may be added to and arbitrarily positioned within a field-flattening shell to create a waveguide that supports a patterned, flattened mode. Patterning does not alter the effective index or flattened nature of the mode, but does alter the characteristics of other modes. Compared to a telecom fiber, a hexagonal pattern of strands allows for a three-fold increase in the flattened mode's area without reducing the separation between its effective index and that of its bend-coupled mode. Hexagonal strand and shell elements prove to be a reasonable approximation, and, thus, to be of practical benefit vis-a-vis fabrication, to those of circular cross section. Patterned flattened modes offer a new and valuable path to power scaling.

  5. Multistaged stokes injected Raman capillary waveguide amplifier

    DOE Patents [OSTI]

    Kurnit, Norman A.

    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.

  6. Propagation of nonlinearly generated harmonic spin waves in microscopic stripes

    SciTech Connect (OSTI)

    Rousseau, O.; Yamada, M.; Miura, K.; Ogawa, S.; Otani, Y.

    2014-02-07

    We report on the experimental study of the propagation of nonlinearly generated harmonic spin waves in microscopic CoFeB stripes. Using an all electrical technique with coplanar waveguides, we find that two kinds of spin waves can be generated by nonlinear frequency multiplication. One has a non-uniform spatial geometry and thus requires appropriate detector geometry to be identified. The other corresponds to the resonant fundamental propagative spin waves and can be efficiently excited by double- or triple-frequency harmonics with any geometry. Nonlinear excited spin waves are particularly efficient in providing an electrical signal arising from spin wave propagation.

  7. Multi-mode interference revealed by two photon absorption in silicon rich SiO{sub 2} waveguides

    SciTech Connect (OSTI)

    Manna, S. E-mail: mattia.mancinelli@unitn.it; Ramiro-Manzano, F.; Mancinelli, M. E-mail: mattia.mancinelli@unitn.it; Turri, F.; Pavesi, L.; Ghulinyan, M.; Pucker, G.

    2015-02-16

    Photoluminescence (PL) from Si nanocrystals (NCs) excited by two-photon absorption (TPA) has been observed in Si nanocrystal-based waveguides fabricated by plasma enhanced chemical vapor deposition. The TPA excited photoluminescence emission resembles the one-photon excited photoluminescence arising from inter-band transitions in the quantum confined Si nanocrystals. By measuring the non-linear transmission of waveguides, a large TPA coefficient of β up to 10{sup −8 }cm/W has been measured at 1550 nm. These values of β depend on the Si NCs size and are two orders of magnitude larger than the bulk silicon value. Here, we propose to use the TPA excited visible PL emission as a tool to map the spatial intensity profile of the 1550 nm propagating optical modes in multimode waveguides. In this way, multimode interference has been revealed experimentally and confirmed through a finite element simulation.

  8. Optical waveguide device with an adiabatically-varying width

    DOE Patents [OSTI]

    Watts; Michael R. , Nielson; Gregory N.

    2011-05-10

    Optical waveguide devices are disclosed which utilize an optical waveguide having a waveguide bend therein with a width that varies adiabatically between a minimum value and a maximum value of the width. One or more connecting members can be attached to the waveguide bend near the maximum value of the width thereof to support the waveguide bend or to supply electrical power to an impurity-doped region located within the waveguide bend near the maximum value of the width. The impurity-doped region can form an electrical heater or a semiconductor junction which can be activated with a voltage to provide a variable optical path length in the optical waveguide. The optical waveguide devices can be used to form a tunable interferometer (e.g. a Mach-Zehnder interferometer) which can be used for optical modulation or switching. The optical waveguide devices can also be used to form an optical delay line.

  9. Control of light diffusion in a disordered photonic waveguide

    SciTech Connect (OSTI)

    Sarma, Raktim; Cao, Hui; Golubev, Timofey; Yamilov, Alexey

    2014-07-28

    We control the diffusion of light in a disordered photonic waveguide by modulating the waveguide geometry. In a single waveguide of varying cross-section, the diffusion coefficient changes spatially in two dimensions due to localization effects. The intensity distribution inside the waveguide agrees with the prediction of the self-consistent theory of localization. Our work shows that wave diffusion can be efficiently manipulated without modifying the structural disorder.

  10. Microminiature optical waveguide structure and method for fabrication

    DOE Patents [OSTI]

    Strand, O.T.; Deri, R.J.; Pocha, M.D.

    1998-12-08

    A method for manufacturing low-cost, nearly circular cross section waveguides comprises starting with a substrate material that a molten waveguide material can not wet or coat. A thin layer is deposited of an opposite material that the molten waveguide material will wet and is patterned to describe the desired surface-contact path pedestals for a waveguide. A waveguide material, e.g., polymer or doped silica, is deposited. A resist material is deposited and unwanted excess is removed to form pattern masks. The waveguide material is etched away to form waveguide precursors and the masks are removed. Heat is applied to reflow the waveguide precursors into near-circular cross-section waveguides that sit atop the pedestals. The waveguide material naturally forms nearly circular cross sections due to the surface tension effects. After cooling, the waveguides will maintain the round shape. If the width and length are the same, then spherical ball lenses are formed. Alternatively, the pedestals can be patterned to taper along their lengths on the surface of the substrate. This will cause the waveguides to assume a conical taper after reflowing by heat. 32 figs.

  11. Microminiature optical waveguide structure and method for fabrication

    DOE Patents [OSTI]

    Strand, Oliver T. (Castro Valley, CA); Deri, Robert J. (Pleasanton, CA); Pocha, Michael D. (Livermore, CA)

    1998-01-01

    A method for manufacturing low-cost, nearly circular cross section waveguides comprises starting with a substrate material that a molten waveguide material can not wet or coat. A thin layer is deposited of an opposite material that the molten waveguide material will wet and is patterned to describe the desired surface-contact path pedestals for a waveguide. A waveguide material, e.g., polymer or doped silica, is deposited. A resist material is deposited and unwanted excess is removed to form pattern masks. The waveguide material is etched away to form waveguide precursors and the masks are removed. Heat is applied to reflow the waveguide precursors into near-circular cross-section waveguides that sit atop the pedestals. The waveguide material naturally forms nearly circular cross sections due to the surface tension effects. After cooling, the waveguides will maintain the round shape. If the width and length are the same, then spherical ball lenses are formed. Alternatively, the pedestals can be patterned to taper along their lengths on the surface of the substrate. This will cause the waveguides to assume a conical taper after reflowing by heat.

  12. Integrated optical tamper sensor with planar waveguide

    DOE Patents [OSTI]

    Carson, Richard F.; Casalnuovo, Stephen A.

    1993-01-01

    A monolithic optical tamper sensor, comprising an optical emitter and detector, connected by an optical waveguide and placed into the critical entry plane of an enclosed sensitive region, the tamper sensor having a myriad of scraps of a material optically absorbent at the wavelength of interest, such that when the absorbent material is in place on the waveguide, an unique optical signature can be recorded, but when entry is attempted into the enclosed sensitive region, the scraps of absorbent material will be displaced and the optical/electrical signature of the tamper sensor will change and that change can be recorded.

  13. Integrated optical tamper sensor with planar waveguide

    DOE Patents [OSTI]

    Carson, R.F.; Casalnuovo, S.A.

    1993-01-05

    A monolithic optical tamper sensor, comprising an optical emitter and detector, connected by an optical waveguide and placed into the critical entry plane of an enclosed sensitive region, the tamper sensor having a myriad of scraps of a material optically absorbent at the wavelength of interest, such that when the absorbent material is in place on the waveguide, an unique optical signature can be recorded, but when entry is attempted into the enclosed sensitive region, the scraps of absorbent material will be displaced and the optical/electrical signature of the tamper sensor will change and that change can be recorded.

  14. DIELECTRIC-LOADED WAVE-GUIDES

    DOE Patents [OSTI]

    Robertson-Shersby-Harvie, R.B.; Mullett, L.B.

    1957-04-23

    This patent presents a particular arrangement for delectric loading of a wave-guide carrying an electromagnetic wave in the E or TM mode of at least the second order, to reduce the power dissipated as the result of conduction loss in the wave-guide walls. To achieve this desirabie result, the effective dielectric constants in the radial direction of adjacent coaxial tubular regions bounded approximateiy by successive nodai surfaces within the electromagnetic field are of two different values alternating in the radial direction, the intermost and outermost regions being of the lower value, and the dielectric constants between nodes are uniform.

  15. Gamma-ray irradiated polymer optical waveguides

    SciTech Connect (OSTI)

    Lai, C.-C.; Wei, T.-Y.; Chang, C.-Y.; Wang, W.-S.; Wei, Y.-Y.

    2008-01-14

    Optical waveguides fabricated by gamma-ray irradiation on polymer through a gold mask are presented. The gamma-ray induced index change is found almost linearly dependent on the dose of the irradiation. And the measured propagation losses are low enough for practical application. Due to the high penetrability of gamma ray, uniform refractive index change in depth can be easily achieved. Moreover, due to large-area printing, the uniformity of waveguide made by gamma-ray irradiation is much better than that by e-beam direct writing.

  16. Compact waveguide power divider with multiple isolated outputs

    DOE Patents [OSTI]

    Moeller, Charles P. (Del Mar, CA)

    1987-01-01

    A waveguide power divider (10) for splitting electromagnetic microwave power and directionally coupling the divided power includes an input waveguide (21) and reduced height output waveguides (23) interconnected by axial slots (22) and matched loads (25) and (26) positioned at the unused ends of input and output guides (21) and (23) respectively. The axial slots are of a length such that the wave in the input waveguide (21) is directionally coupled to the output waveguides (23). The widths of input guide (21) and output guides (23) are equal and the width of axial slots (22) is one half of the width of the input guide (21).

  17. Dielectric waveguide gas-filled stark shift modulator

    DOE Patents [OSTI]

    Hutchinson, Donald P.; Richards, Roger K.

    2003-07-22

    An optical modulator includes a dielectric waveguide for receiving an optical beam and coupling energy of the optical beam into the waveguide. At least one Stark material is provided in the waveguide. A bias circuit generates a bias signal to produce an electrical field across the Stark material to shift at least one of the Stark absorption frequencies towards the frequency of the optical beam. A circuit for producing a time varying electric field across the Stark material modulates the optical beam. At least a portion of the bias field can be generated by an alternating bias signal, such as a square wave. A method of modulating optical signals includes the steps of providing a dielectric waveguide for receiving an optical beam and coupling energy of the optical beam into the waveguide, the waveguide having at least one Stark material disposed therein, and varying an electric field imposed across the Stark material.

  18. Surface enhanced Raman scattering spectroscopic waveguide

    SciTech Connect (OSTI)

    Lascola, Robert J; McWhorter, Christopher S; Murph, Simona H

    2015-04-14

    A waveguide for use with surface-enhanced Raman spectroscopy is provided that includes a base structure with an inner surface that defines a cavity and that has an axis. Multiple molecules of an analyte are capable of being located within the cavity at the same time. A base layer is located on the inner surface of the base structure. The base layer extends in an axial direction along an axial length of an excitation section. Nanoparticles are carried by the base layer and may be uniformly distributed along the entire axial length of the excitation section. A flow cell for introducing analyte and excitation light into the waveguide and a method of applying nanoparticles may also be provided.

  19. Waveguide mode converter and method using same

    DOE Patents [OSTI]

    Moeller, Charles P.

    1990-01-01

    A waveguide mode converter converts electromagnetic power being transmitted in a TE.sub.0n or a TM.sub.0n mode, where n is an integer, to an HE.sub.11 mode. The conversion process occurs in a single stage without requiring the power to pass through any intermediate modes. The converter comprises a length of circular corrugated waveguide formed in a multiperiod periodic curve. The period of the curve is selected to couple the desired modes and decouple undesired modes. The corrugation depth is selected to control the phase propagation constant, or wavenumbers, of the input and output modes, thereby preventing coherent coupling to competing modes. In one embodiment, both the period and amplitude of the curve may be selectively adjusted, thereby allowing the converter to be tuned to maximize the conversion efficiency.

  20. Wideband unbalanced waveguide power dividers and combiners (Patent...

    Office of Scientific and Technical Information (OSTI)

    Patent: Wideband unbalanced waveguide power dividers and combiners Citation Details ... DOE Contract Number: AC04-94AL85000 Resource Type: Patent Resource Relation: Patent File ...

  1. Pulse shaping using nonlinear dielectric SrTiO{sub 3}

    SciTech Connect (OSTI)

    Findikoglu, A.T.; Reagor, D.W.; Rasmussen, K.O.; Bishop, A.R.; Gronbech-Jensen, N.; Jia, Q.X.; Fan, Y.; Kwon, C.

    1999-03-01

    We have studied electromagnetic pulse shaping in coplanar waveguide delay lines made from superconducting YBa{sub 2}Cu{sub 3}O{sub 7{minus}{delta}} electrodes on nonlinear dielectric SrTiO{sub 3} single-crystal substrates. The delay lines exhibited bias- and temperature-dependent nonlinearity and dispersion, with associated pulse-shaping effects. At low temperatures and under certain bias conditions, the interplay of dispersion and nonlinearity has led to stable and compact wave forms, reminiscent of microwave solitons. {copyright} {ital 1999 American Institute of Physics.}

  2. Center for Nonlinear Studies

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

    Applied Geophysical Experiences Materials Design Calendar NSEC Center for Nonlinear Studies Center for Nonlinear Studies Serving as an interface between mission...

  3. Hollow cylindrical plasma filament waveguide with discontinuous finite thickness cladding

    SciTech Connect (OSTI)

    Alshershby, Mostafa; Hao Zuoqiang; Lin Jingquan

    2013-01-15

    We have explored here a hollow cylindrical laser plasma multifilament waveguide with discontinuous finite thickness cladding, in which the separation between individual filaments is in the range of several millimeters and the waveguide cladding thickness is in the order of the microwave penetration depth. Such parameters give a closer representation of a realistic laser filament waveguide sustained by a long stable propagation of femtosecond (fs) laser pulses. We report how the waveguide losses depend on structural parameters like normalized plasma filament spacing, filament to filament distance or pitch, normal spatial frequency, and radius of the plasma filament. We found that for typical plasma parameters, the proposed waveguide can support guided modes of microwaves in extremely high frequency even with a cladding consisting of only one ring of plasma filaments. The loss of the microwave radiation is mainly caused by tunneling through the discontinuous finite cladding, i.e., confinement loss, and is weakly dependent on the plasma absorption. In addition, the analysis indicates that the propagation loss is fairly large compared with the loss of a plasma waveguide with a continuous infinite thickness cladding, while they are comparable when using a cladding contains more than one ring. Compared to free space propagation, this waveguide still presents a superior microwave transmission to some distance in the order of the filamentation length; thus, the laser plasma filaments waveguide may be a potential channel for transporting pulsed-modulated microwaves if ensuring a long and stable propagation of fs laser pulses.

  4. WAVE DELAYING STRUCTURE FOR RECTANGULAR WAVE-GUIDES

    DOE Patents [OSTI]

    Robertson-Shersby-Harvie, R.B.; Dain, J.

    1956-11-13

    This patent relates to wave-guides and in particular describes wave delaying structure located within a wave-guide. The disclosed wave-guide has an elongated fiat metal sheet arranged in a central plane of the guide and formed with a series of transverse inductive slots such that each face presents an inductive impedance to the guide. The sheet is thickened in the area between slots to increase the self capacity of the slots. Experimental results indicate that in a wave-guide loaded in accordance with the invention the guided wavelength changes more slowly as the air wavelength is changed than the guided wavelength does in wave-guides loaded by means of corrugations.

  5. Waveguides for performing spectroscopy with confined effective observation volumes

    DOE Patents [OSTI]

    Levene, Michael J.; Korlach, Jonas; Turner, Stephen W.; Craighead, Harold G.; Webb, Watt W.

    2006-03-14

    The present invention is directed to a method and an apparatus for analysis of an analyte. The method involves providing a zero-mode waveguide which includes a cladding surrounding a core where the cladding is configured to preclude propagation of electromagnetic energy of a frequency less than a cutoff frequency longitudinally through the core of the zero-mode waveguide. The analyte is positioned in the core of the zero-mode waveguide and is then subjected, in the core of the zero-mode waveguide, to activating electromagnetic radiation of a frequency less than the cut-off frequency under conditions effective to permit analysis of the analyte in an effective observation volume which is more compact than if the analysis were carried out in the absence of the zero-mode waveguide.

  6. Combination ring cavity and backward Raman waveguide amplifier

    DOE Patents [OSTI]

    Kurnit, Norman A.

    1983-01-01

    A combination regenerative ring and backward Raman waveguide amplifier and a combination regenerative ring oscillator and backward Raman waveguide amplifier which produce Raman amplification, pulse compression, and efficient energy extraction from the CO.sub.2 laser pump signal for conversion into a Stokes radiation signal. The ring cavity configuration allows the CO.sub.2 laser pump signal and Stokes signal to copropagate through the Raman waveguide amplifier. The backward Raman waveguide amplifier configuration extracts a major portion of the remaining energy from the CO.sub.2 laser pump signal for conversion to Stokes radiation. Additionally, the backward Raman amplifier configuration produces a Stokes radiation signal which has a high intensity and a short duration. Adjustment of the position of overlap of the Stokes signal and the CO.sub.2 laser pump signal in the backward Raman waveguide amplifiers alters the amount of pulse compression which can be achieved.

  7. Nanoscale constrictions in superconducting coplanar waveguide resonators

    SciTech Connect (OSTI)

    Jenkins, Mark David; Naether, Uta; Ciria, Miguel; Zueco, David; Luis, Fernando; Ses, Javier; Atkinson, James; Barco, Enrique del; Snchez-Azqueta, Carlos; Majer, Johannes

    2014-10-20

    We report on the design, fabrication, and characterization of superconducting coplanar waveguide resonators with nanoscopic constrictions. By reducing the size of the center line down to 50?nm, the radio frequency currents are concentrated and the magnetic field in its vicinity is increased. The device characteristics are only slightly modified by the constrictions, with changes in resonance frequency lower than 1% and internal quality factors of the same order of magnitude as the original ones. These devices could enable the achievement of higher couplings to small magnetic samples or even to single molecular spins and have applications in circuit quantum electrodynamics, quantum computing, and electron paramagnetic resonance.

  8. Stokes injected Raman capillary waveguide amplifier

    DOE Patents [OSTI]

    Kurnit, Norman A.

    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.

  9. Center for Nonlinear Studies

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

    Center for Nonlinear Studies Center for Nonlinear Studies We conduct and support basic scientific research in nonlinear and complex systems phenomena and promote their use in applied research programs. Contact CNLS Office (505) 667-1444 Email Leader Robert Ecke (505) 667-6733 Email Conducting and supporting basic scientific research in nonlinear and complex systems phenomena The Center for Nonlinear Studies (CNLS) at Los Alamos chooses a small number (two to three) focus topics periodically and

  10. Quantitative study of rectangular waveguide behavior in the THz.

    SciTech Connect (OSTI)

    Rowen, Adam M.; Nordquist, Christopher Daniel; Wanke, Michael Clement

    2009-10-01

    This report describes our efforts to quantify the behavior of micro-fabricated THz rectangular waveguides on a configurable, robust semiconductor-based platform. These waveguides are an enabling technology for coupling THz radiation directly from or to lasers, mixers, detectors, antennas, and other devices. Traditional waveguides fabricated on semiconductor platforms such as dielectric guides in the infrared or co-planar waveguides in the microwave regions, suffer high absorption and radiative losses in the THz. The former leads to very short propagation lengths, while the latter will lead to unwanted radiation modes and/or crosstalk in integrated devices. This project exploited the initial developments of THz micro-machined rectangular waveguides developed under the THz Grand Challenge Program, but instead of focusing on THz transceiver integration, this project focused on exploring the propagation loss and far-field radiation patterns of the waveguides. During the 9 month duration of this project we were able to reproduce the waveguide loss per unit of length in the waveguides and started to explore how the loss depended on wavelength. We also explored the far-field beam patterns emitted by H-plane horn antennas attached to the waveguides. In the process we learned that the method of measuring the beam patterns has a significant impact on what is actually measured, and this may have an effect on most of the beam patterns of THz that have been reported to date. The beam pattern measurements improved significantly throughout the project, but more refinements of the measurement are required before a definitive determination of the beam-pattern can be made.

  11. Quasi-phase matching and quantum control of high harmonic generation in waveguides using counterpropagating beams

    DOE Patents [OSTI]

    Zhang, Xiaoshi; Lytle, Amy L.; Cohen, Oren; Kapteyn, Henry C.; Murnane, Margaret M.

    2010-11-09

    All-optical quasi-phase matching (QPM) uses a train of counterpropagating pulses to enhance high-order harmonic generation (HHG) in a hollow waveguide. A pump pulse enters one end of the waveguide, and causes HHG in the waveguide. The counterpropagation pulses enter the other end of the waveguide and interact with the pump pulses to cause QPM within the waveguide, enhancing the HHG.

  12. Radio frequency (RF) microwave components and subsystems using loaded ridge waveguide

    DOE Patents [OSTI]

    Kang, Yoon W.

    2013-08-20

    A waveguide having a non-conductive material with a high permeability (.mu., .mu..sub.r for relative permeability) and/or a high permittivity (.di-elect cons., .di-elect cons..sub.r for relative permittivity) positioned within a housing. When compared to a hollow waveguide, the waveguide of this invention, reduces waveguide dimensions by .varies..mu. ##EQU00001## The waveguide of this invention further includes ridges which further reduce the size and increases the usable frequency bandwidth.

  13. Solving Large Scale Nonlinear Eigenvalue Problem in Next-Generation Accelerator Design

    SciTech Connect (OSTI)

    Liao, Ben-Shan; Bai, Zhaojun; Lee, Lie-Quan; Ko, Kwok; /SLAC

    2006-09-28

    A number of numerical methods, including inverse iteration, method of successive linear problem and nonlinear Arnoldi algorithm, are studied in this paper to solve a large scale nonlinear eigenvalue problem arising from finite element analysis of resonant frequencies and external Q{sub e} values of a waveguide loaded cavity in the next-generation accelerator design. They present a nonlinear Rayleigh-Ritz iterative projection algorithm, NRRIT in short and demonstrate that it is the most promising approach for a model scale cavity design. The NRRIT algorithm is an extension of the nonlinear Arnoldi algorithm due to Voss. Computational challenges of solving such a nonlinear eigenvalue problem for a full scale cavity design are outlined.

  14. Gap solitons in rocking optical lattices and waveguides with undulating gratings

    SciTech Connect (OSTI)

    Mayteevarunyoo, Thawatchai; Malomed, Boris A.

    2009-07-15

    We report results of a systematic analysis of the stability of one-dimensional solitons in a model including the self-repulsive or attractive cubic nonlinearity and a linear potential represented by a periodically shaking lattice, which was recently implemented in experiments with Bose-Einstein condensates. In optics, the same model applies to undulated waveguiding arrays, which are also available to the experiment. In the case of the repulsive nonlinearity, stability regions are presented, in relevant parameter planes, for fundamental gap solitons and their two-peak and three-peak bound complexes, in the first and second finite band gaps. In the model with the attractive nonlinearity, stability regions are produced for fundamental solitons and their bound states populating the semi-infinite gap. In the first finite and semi-infinite gaps, unstable solitons gradually decay into radiation, while, in the second finite band gap, they are transformed into more complex states, which may represent new species of solitons. For a large amplitude of the rocking-lattice drive, the model is tantamount to that with a 'flashing' lattice potential, which is controlled by periodic sequences of instantaneous kicks. Using this correspondence, we explain generic features of the stability diagrams for the solitons. We also derive a limit case of the latter system, in the form of coupled-mode equations with a 'flashing' linear coupling.

  15. Compact cladding-pumped planar waveguide amplifier and fabrication method

    DOE Patents [OSTI]

    Bayramian, Andy J.; Beach, Raymond J.; Honea, Eric; Murray, James E.; Payne, Stephen A.

    2003-10-28

    A low-cost, high performance cladding-pumped planar waveguide amplifier and fabrication method, for deployment in metro and access networks. The waveguide amplifier has a compact monolithic slab architecture preferably formed by first sandwich bonding an erbium-doped core glass slab between two cladding glass slabs to form a multi-layer planar construction, and then slicing the construction into multiple unit constructions. Using lithographic techniques, a silver stripe is deposited and formed at a top or bottom surface of each unit construction and over a cross section of the bonds. By heating the unit construction in an oven and applying an electric field, the silver stripe is then ion diffused to increase the refractive indices of the core and cladding regions, with the diffusion region of the core forming a single mode waveguide, and the silver diffusion cladding region forming a second larger waveguide amenable to cladding pumping with broad area diodes.

  16. 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.

  17. Center for Nonlinear Studies

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

    NSEC » Center for Nonlinear Studies Center for Nonlinear Studies Serving as an interface between mission critical research at LANL and the outside research community. Contact Director Robert Ecke (505) 667-6733 Email Deputy Director Aric Hagberg (505) 665-4958 Email Executive Administrator Elissa (Ellie) Vigil (505) 667-2818 Email Identify and study complex nonlinear phenomena using a diverse set of research approaches and methodologies, particularly those of statistical physics, nonlinear

  18. Raman scattering in a whispering mode optical waveguide

    DOE Patents [OSTI]

    Kurnit, Norman A.

    1982-01-01

    A device and method for Raman scattering in a whispering mode optical waveguide. Both a helical ribbon and cylinder are disclosed which incorporate an additional curvature .rho. p for confining the beam to increase intensity. A Raman scattering medium is disposed in the optical path of the beam as it propagates along the waveguide. Raman scattering is enhanced by the high intensities of the beam and long interaction path lengths which are achieved in a small volume.

  19. Slow Waveguide Structures for Particle Accelerators - Energy Innovation

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

    Portal Energy Analysis Energy Analysis Electricity Transmission Electricity Transmission Early Stage R&D Early Stage R&D Find More Like This Return to Search Slow Waveguide Structures for Particle Accelerators Oak Ridge National Laboratory Contact ORNL About This Technology Technology Marketing SummaryA waveguide design that can save time and money in the construction and tuning of a particle accelerator was developed by ORNL researchers. Particle accelerators use electromagnetic

  20. Dispersion of helically corrugated waveguides: Analytical, numerical, and experimental study

    SciTech Connect (OSTI)

    Burt, G.; Ronald, K.; Young, A.R.; Phelps, A.D.R.; Cross, A.W.; Konoplev, I.V.; He, W.; Thomson, J.; Whyte, C.G.; Samsonov, S.V.; Denisov, G.G.; Bratman, V.L.

    2004-10-01

    Helically corrugated waveguides have recently been studied for use in various applications such as interaction regions in gyrotron traveling-wave tubes and gyrotron backward-wave oscillators and as a dispersive medium for passive microwave pulse compression. The paper presents a summary of various methods that can be used for analysis of the wave dispersion of such waveguides. The results obtained from an analytical approach, simulations with the three-dimensional numerical code MAGIC, and cold microwave measurements are analyzed and compared.

  1. Simulation of waveguide FEL oscillator using RF linac

    SciTech Connect (OSTI)

    Kuruma, S.; Asakawa, M.; Imasaki, K.

    1995-12-31

    One dimensional multifrequency simulation code for waveguide mode FEL has been developed. Using this simulation code, we analyzed the spontaneous emission from electron micropulse from RF Linac. It is found that some parameters both high and low frequency waveguide modes are growing simultaneously, so the two radiation pulses are generated and amplified. And the experimental data for cavity length detuning of the radiation power are analyzed.

  2. Optical pumping in a whispering mode optical waveguide

    DOE Patents [OSTI]

    Kurnit, Norman A.

    1984-01-01

    A device and method for optical pumping in a whispering mode optical waveguide. Both a helical ribbon and cylinder are disclosed which incorporate an additional curvature for confining the beam to increase intensity. An optical pumping medium is disposed in the optical path of the beam as it propagates along the waveguide. Optical pumping is enhanced by the high intensities of the beam and long interaction pathlengths which are achieved in a small volume.

  3. Optical pumping in a whispering-mode optical waveguide

    DOE Patents [OSTI]

    Kurnit, N.A.

    1981-08-11

    A device and method for optical pumping in a whispering mode optical waveguide are described. Both a helical ribbon and cylinder are disclosed which incorporate an additional curvature for confining the beam to increase intensity. An optical pumping medium is disposed in the optical path of the beam as it propagates along the waveguide. Optical pumping is enhanced by the high intensities of the beam and long interaction path lengths which are achieved in a small volume.

  4. Low-loss bloch wave guiding in open structures and highly compact efficient waveguide-crossing arrays

    DOE Patents [OSTI]

    Popovic, Milos

    2011-03-08

    Low-loss waveguide structures may comprise a multimode waveguide supporting a periodic light intensity pattern, and attachments disposed at the waveguide adjacent low-intensity regions of the light intensity pattern.

  5. Loss and thermal noise in plasmonic waveguides

    SciTech Connect (OSTI)

    Syms, R. R. A. Solymar, L.

    2014-06-07

    Rytov's theory of thermally generated radiation is used to find the noise in two-dimensional passive guides based on an arbitrary distribution of lossy isotropic dielectric. To simplify calculations, the Maxwell curl equations are approximated using difference equations that also permit a transmission-line analogy, and material losses are assumed to be low enough for modal losses to be estimated using perturbation theory. It is shown that an effective medium representation of each mode is valid for both loss and noise and, hence, that a one-dimensional model can be used to estimate the best achievable noise factor when a given mode is used in a communications link. This model only requires knowledge of the real and imaginary parts of the modal dielectric constant. The former can be found by solving the lossless eigenvalue problem, while the latter can be estimated using perturbation theory. Because of their high loss, the theory is most relevant to plasmonic waveguides, and its application is demonstrated using single interface, slab, and slot guide examples. The best noise performance is offered by the long-range plasmon supported by the slab guide.

  6. Waveguide detection of right-angle-scattered light in flow cytometry

    DOE Patents [OSTI]

    Mariella, Jr., Raymond P.

    2000-01-01

    A transparent flow cell is used as an index-guided optical waveguide. A detector for the flow cell but not the liquid stream detects the Right-Angle-Scattered (RAS) Light exiting from one end of the flow cell. The detector(s) could view the trapped RAS light from the flow cell either directly or through intermediate optical light guides. If the light exits one end of the flow cell, then the other end of the flow cell can be given a high-reflectivity coating to approximately double the amount of light collected. This system is more robust in its alignment than the traditional flow cytometry systems which use imaging optics, such as microscope objectives.

  7. Controlling guided modes in plasmonic metal/dielectric multilayer waveguides

    SciTech Connect (OSTI)

    Wickremasinghe, N.; Wang, X.; Wagner, H. P.; Thompson, J.; Schmitzer, H.

    2015-06-07

    We investigate the mode properties of planar dielectric aluminum-quinoline (Alq{sub 3}) multilayer waveguides comprising one single or three equally spaced embedded nanometer-thin (∼10 nm thick) Alq{sub 3}-Mg{sub 0.9}:Ag{sub 0.1} composite metal-island layers. The plasmonic waveguides were fabricated by organic molecular beam deposition. Transverse magnetic (TM) and transverse electric (TE) modes were selectively excited using the m-line method. The symmetric plasmonic TM{sub 0} mode was launched in all waveguides and—in addition—two higher order plasmonic TM{sub 1} and TM{sub 2} modes were generated in waveguides comprising three metal layers. Other TM modes have hybrid dielectric-plasmonic characters, showing an increased effective refractive index when one electric field antinode is close to a metallic layer. TM modes which have all their antinode(s) in the dielectric layers propagate essentially like dielectric modes. TE modes with antinode(s) at the position of the metal layer(s) are strongly damped while the losses are low for TE modes comprising a node at the position of the composite metal film(s). The possibility to control the effective refractive index and the losses for individual hybrid plasmonic-dielectric TM and dielectric TE modes opens new design opportunities for mode selective waveguides and TM-TE mode couplers.

  8. Stationary nonlinear Airy beams

    SciTech Connect (OSTI)

    Lotti, A.; Faccio, D.; Couairon, A.; Papazoglou, D. G.; Panagiotopoulos, P.; Tzortzakis, S.; Abdollahpour, D.

    2011-08-15

    We demonstrate the existence of an additional class of stationary accelerating Airy wave forms that exist in the presence of third-order (Kerr) nonlinearity and nonlinear losses. Numerical simulations and experiments, in agreement with the analytical model, highlight how these stationary solutions sustain the nonlinear evolution of Airy beams. The generic nature of the Airy solution allows extension of these results to other settings, and a variety of applications are suggested.

  9. Monolithically integrated solid state laser and waveguide using spin-on glass

    DOE Patents [OSTI]

    Ashby, Carol I. H.; Hohimer, John P.; Neal, Daniel R.; Vawter, G. Allen

    1995-01-01

    A monolithically integrated photonic circuit combining a semiconductor source of excitation light with an optically active waveguide formed on the substrate. The optically active waveguide is preferably formed of a spin-on glass to which are added optically active materials which can enable lasing action, optical amplification, optical loss, or frequency conversion in the waveguide, depending upon the added material.

  10. Low loss, high and low index contrast waveguides in semiconductors

    DOE Patents [OSTI]

    Bond, Tiziana; Cole, Garrett; Goddard, Lynford; Kallman, Jeff

    2011-08-09

    A system in one general embodiment includes a waveguide structure comprising a core of an alloy of Group III-V materials surrounded by an oxide (which may include one or more Group III-V metals), wherein an interface of the oxide and core is characterized by oxidation of the alloy for defining the core. A method in one general approach includes oxidizing a waveguide structure comprising an alloy of Group III-V materials for forming a core of the alloy surrounded by an oxide.

  11. High efficiency source coupler for optical waveguide illumination system

    DOE Patents [OSTI]

    Siminovitch, Michael J.

    2000-01-01

    A fiber optic or optical waveguide illumination system includes a source coupling system. The source coupling system includes an optical channel with an internal cavity. A light source is disposed inside the driving circuit. Coupling losses are minimized by placing the light source within the optical channel. The source cavity and the source optical channel can be shaped to enhance the amount of light captured in the channel by total internal reflection. Multiple light distribution waveguides can be connected to the source coupling channel to produce an illumination system.

  12. On the vector Helmholtz equation in toroidal waveguides

    SciTech Connect (OSTI)

    Biro, Thomas

    2005-02-15

    A wave splitting method is proposed to solve the problem of propagation of microwaves in a circular waveguide bend of circular cross section. The splitting method, applied to the vector Helmholtz equation, gives a stable solution in terms of waves propagating to the right and to the left in the bend. The formulation is particularly transparent for analyzing the scattering properties of toroidal bends. The basis for the transparency of the method is that the wave splitting is formally exact as the exponential of the square root of a differential operator. The modal functions of the straight cylindrical waveguide are chosen as basis functions in the transverse quasi-toroidal variables.

  13. Ring cavity for a Raman capillary waveguide amplifir

    DOE Patents [OSTI]

    Kurnit, N.A.

    1981-01-27

    A regenerative ring amplifier and regenerative ring oscillator are described which function to feed back a portion of the Stokes signal to complete the ring cavity. The ring cavity configuration allows the CO/sub 2/ laser pump signal and Stokes signal to copropagate through the Raman capillary waveguide amplifier. A Raman capillary waveguide amplifier is also provided in the return leg of the ring cavity to increase gain without increasing the round trip time. Additionally, the ring cavity can be designed such that the amplified Stokes signal is synchronous with the mode-locked spikes of the incoming CO/sub 2/ laser pump signal.

  14. Ring cavity for a Raman capillary waveguide amplifier

    DOE Patents [OSTI]

    Kurnit, N.A.

    1983-07-19

    Disclosed is a regenerative ring amplifier and regenerative ring oscillator which function to feed back a portion of the Stokes signal to complete the ring cavity. The ring cavity configuration allows the CO[sub 2] laser pump signal and Stokes signal to copropagate through the Raman capillary waveguide amplifier. A Raman capillary waveguide amplifier is also provided in the return leg of the ring cavity to increase gain without increasing the round trip time. Additionally, the ring cavity can be designed such that the amplifier Stokes signal is synchronous with the mode-locked spikes of the incoming CO[sub 2] laser pump signal. 6 figs.

  15. Ring cavity for a raman capillary waveguide amplifier

    DOE Patents [OSTI]

    Kurnit, Norman A.

    1983-07-19

    A regenerative ring amplifier and regenerative ring oscillator which function to feed back a portion of the Stokes signal to complete the ring cavity. The ring cavity configuration allows the CO.sub.2 laser pump signal and Stokes signal to copropagate through the Raman capillary waveguide amplifier. A Raman capillary waveguide amplifier is also provided in the return leg of the ring cavity to increase gain without increasing the round trip time. Additionally, the ring cavity can be designed such that the amplifier Stokes signal is synchronous with the mode-locked spikes of the incoming CO.sub.2 laser pump signal.

  16. Ring cavity for a Raman capillary waveguide amplifier

    DOE Patents [OSTI]

    Kurnit, N.A.

    1981-01-27

    A regenerative ring amplifier and regenerative ring oscillator are described which function to feed back a portion of the Stokes signal to complete the ring cavity. The ring cavity configuration allows the CO/sub 2/ laser pump signal and Stokes signal to copropagate through the Raman capillary waveguide amplifier. A Raman capillary waveguide amplifier is also provided in the return leg of the ring cavity to increase gain without increasing the round trip time. Additionally, the ring cavity can be designed such that the amplified Stokes signal is synchronous with the mode-locked spikes of the incoming CO/sub 2/ laser pump signal.

  17. Cross-talk dynamics of optical solitons in a broadband Kerr nonlinear system with weak cubic loss

    SciTech Connect (OSTI)

    Peleg, Avner; Nguyen, Quan M.; Chung, Yeojin

    2010-11-15

    We study the dynamics of fast soliton collisions in a Kerr nonlinear optical waveguide with weak cubic loss. We obtain analytic expressions for the amplitude and frequency shifts in a single two-soliton collision and show that the impact of a fast three-soliton collision is given by the sum of the two-soliton interactions. Our analytic predictions are confirmed by numerical simulations with the perturbed nonlinear Schroedinger (NLS) equation. Furthermore, we show that the deterministic collision-induced dynamics of soliton amplitudes in a broadband waveguide system with N frequency channels is described by a Lotka-Volterra model for N competing species. For a two-channel system we find that stable transmission with equal prescribed amplitudes can be achieved by a proper choice of linear amplifier gain. The predictions of the Lotka-Volterra model are confirmed by numerical solution of a perturbed coupled-NLS model.

  18. Dielectric waveguide with transverse index variation that support a zero group velocity mode at a non-zero longitudinal wavevector

    DOE Patents [OSTI]

    Ibanescu, Mihai; Joannopoious, John D.; Fink, Yoel; Johnson, Steven G.; Fan, Shanhui

    2005-06-21

    Optical components including a laser based on a dielectric waveguide extending along a waveguide axis and having a refractive index cross-section perpendicular to the waveguide axis, the refractive index cross-section supporting an electromagnetic mode having a zero group velocity for a non-zero wavevector along the waveguide axis.

  19. Cutoff-mesa isolated rib optical waveguide for III-V heterostructure photonic integrated circuits

    DOE Patents [OSTI]

    Vawter, Gregory A.; Smith, Robert E.

    1998-01-01

    A cutoff mesa rib waveguide provides single-mode performance regardless of any deep etches that might be used for electrical isolation between integrated electrooptic devices. Utilizing a principle of a cutoff slab waveguide with an asymmetrical refractive index profile, single mode operation is achievable with a wide range of rib widths and does not require demanding etch depth tolerances. This new waveguide design eliminates reflection effects, or self-interference, commonly seen when conventional rib waveguides are combined with deep isolation etches and thereby reduces high order mode propagation and crosstalk compared to the conventional rib waveguides.

  20. Coupler for coupling gyrotron whispering gallery mode RF into HE11 waveguide

    DOE Patents [OSTI]

    Neilson, Jeffrey M

    2015-02-24

    A cylindrical waveguide with a mode converter transforms a whispering gallery mode from a gyrotron cylindrical waveguide with a helical cut launch edge to a quasi-Gaussian beam suitable for conveyance through a corrugated waveguide. This quasi-Gaussian beam is radiated away from the waveguide using a spiral cut launch edge, which is in close proximity to a first mode converting reflector. The first mode converting reflector is coupled to a second mode converting reflector which provides an output free-space HE11 mode wave suitable for direct coupling into a corrugated waveguide. The radiated beam produced at the output of the second mode converting reflector is substantially circular.

  1. Cutoff-mesa isolated rib optical waveguide for III-V heterostructure photonic integrated circuits

    DOE Patents [OSTI]

    Vawter, G.A.; Smith, R.E.

    1998-04-28

    A cutoff mesa rib waveguide provides single-mode performance regardless of any deep etches that might be used for electrical isolation between integrated electrooptic devices. Utilizing a principle of a cutoff slab waveguide with an asymmetrical refractive index profile, single mode operation is achievable with a wide range of rib widths and does not require demanding etch depth tolerances. This new waveguide design eliminates reflection effects, or self-interference, commonly seen when conventional rib waveguides are combined with deep isolation etches and thereby reduces high order mode propagation and crosstalk compared to the conventional rib waveguides. 7 figs.

  2. Low-power, ultrafast, and dynamic all-optical tunable plasmonic analog to electromagnetically induced transparency in two resonators side-coupled with a waveguide system

    SciTech Connect (OSTI)

    Wang, Boyun; Wang, Tao Li, Xiaoming; Han, Xu; Zhu, Youjiang

    2015-06-07

    We theoretically and numerically investigate a low-power, ultrafast, and dynamic all-optical tunable plasmonic analog to electromagnetically induced transparency (EIT) in two nanodisk resonators side-coupled to a metal-insulator-metal plasmonic waveguide system. The optical Kerr effect is enhanced by the slow light effect of the plasmonic EIT-like effect and the plasmonic waveguide based on graphene-Ag composite material structures with giant effective Kerr nonlinear coefficient. The optical Kerr effect modulation method is applied to improve tuning rate with response time of subpicoseconds or even femtoseconds. With dynamically tuning the propagation phase of the plasmonic waveguide, π-phase shift of the transmission spectrum in the plasmonic EIT-like system is achieved under excitation of a pump light with an intensity as low as 5.85 MW/cm{sup 2}. The group delay is controlled between 0.09 and 0.4 ps. All observed schemes are analyzed rigorously through finite-difference time-domain simulations and coupled-mode formalism. Results show a new direction toward the low power consumption and ultrafast responses of integration plasmonic photonic devices and all-optical dynamical storage of light devices in optical communication and quantum information processing.

  3. Library for Nonlinear Optimization

    Energy Science and Technology Software Center (OSTI)

    2001-10-09

    OPT++ is a C++ object-oriented library for nonlinear optimization. This incorporates an improved implementation of an existing capability and two new algorithmic capabilities based on existing journal articles and freely available software.

  4. Nonlinear Laser Spectroscopy

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

    ... Nonlinear optical techniques investigated in this program include time-resolved coherent anti-Stokes Raman spectroscopy, degenerate four-wave mixing, coherent 1D and 2D imaging ...

  5. A 2.5D boundary element formulation for modeling damped waves in arbitrary cross-section waveguides and cavities

    SciTech Connect (OSTI)

    Mazzotti, M.; Civil, Architectural and Environmental Engineering Department, Drexel University, 3141 Chestnut St., Philadelphia, PA 19104 ; Bartoli, I.; Marzani, A.; Viola, E.

    2013-09-01

    Highlights: Dispersive properties of viscoelastic waveguides and cavities are computed using a regularized 2.5D BEM. Linear viscoelasticity is introduced at the constitutive level by means of frequency dependent complex moduli. A contour integral algorithm is used to solve the nonlinear eigenvalue problem. The Sommerfeld radiation condition is used to select the permissible Riemann sheets. Attenuation of surface waves in cavities approaches the attenuation of Rayleigh waves. -- Abstract: A regularized 2.5D boundary element method (BEM) is proposed to predict the dispersion properties of damped stress guided waves in waveguides and cavities of arbitrary cross-section. The wave attenuation, induced by material damping, is introduced using linear viscoelastic constitutive relations and described in a spatial manner by the imaginary component of the axial wavenumber. The discretized dispersive wave equation results in a nonlinear eigenvalue problem, which is solved obtaining complex axial wavenumbers for a fixed frequency using a contour integral algorithm. Due to the singular characteristics and the multivalued feature of the wave equation, the requirement of holomorphicity inside the contour region over the complex wavenumber plane is fulfilled by the introduction of the Sommerfeld branch cuts and by the choice of the permissible Riemann sheets. A post processing analysis is developed for the extraction of the energy velocity of propagative guided waves. The reliability of the method is demonstrated by comparing the results obtained for a rail and a bar with square cross-section with those obtained from a 2.5D Finite Element formulation also known in literature as Semi Analytical Finite Element (SAFE) method. Next, to show the potential of the proposed numerical framework, dispersion properties are predicted for surface waves propagating along cylindrical cavities of arbitrary cross-section. It is demonstrated that the attenuation of surface waves approaches

  6. JOBAID-VIEWING USER RECORDS

    Broader source: Energy.gov [DOE]

    In this job aid you will View To-Do List using Filter and View options, View Completed Work, and View Curriculum Status and Detials areas. 

  7. Vertically-tapered optical waveguide and optical spot transformer formed therefrom

    DOE Patents [OSTI]

    Bakke, Thor; Sullivan, Charles T.

    2004-07-27

    An optical waveguide is disclosed in which a section of the waveguide core is vertically tapered during formation by spin coating by controlling the width of an underlying mesa structure. The optical waveguide can be formed from spin-coatable materials such as polymers, sol-gels and spin-on glasses. The vertically-tapered waveguide section can be used to provide a vertical expansion of an optical mode of light within the optical waveguide. A laterally-tapered section can be added adjacent to the vertically-tapered section to provide for a lateral expansion of the optical mode, thereby forming an optical spot-size transformer for efficient coupling of light between the optical waveguide and a single-mode optical fiber. Such a spot-size transformer can also be added to a III-V semiconductor device by post processing.

  8. Method of fabricating optical waveguides by ion implantation doping

    DOE Patents [OSTI]

    Appleton, B.R.; Ashley, P.R.; Buchal, C.J.

    1987-03-24

    A method for fabricating high-quality optical waveguides in optical quality oxide crystals by ion implantation doping and controlled epitaxial recrystallization is provided. Masked LiNbO/sub 3/ crystals are implanted with high concentrations of Ti dopant at ion energies of about 360 keV while maintaining the crystal near liquid nitrogen temperature. Ion implantation doping produces an amorphous, Ti-rich nonequilibrium phase in the implanted region. Subsequent thermal annealing in a water-saturated oxygen atmosphere at up to 1000/degree/C produces solid-phase epitaxial regrowth onto the crystalline substrate. A high-quality crystalline layer results which incorporates the Ti into the crystal structure at much higher concentrations than is possible by standard diffusion techniques, and this implanted region has excellent optical waveguiding properties.

  9. Method of fabricating optical waveguides by ion implantation doping

    DOE Patents [OSTI]

    Appleton, Bill R.; Ashley, Paul R.; Buchal, Christopher J.

    1989-01-01

    A method for fabricating high-quality optical waveguides in optical quality oxide crystals by ion implantation doping and controlled epitaxial recrystallization is provided. Masked LiNbO.sub.3 crystals are implanted with high concentrations of Ti dopant at ion energies of about 350 keV while maintaining the crystal near liquid nitrogen temperature. Ion implantation doping produces an amorphous, Ti-rich nonequilibrium phase in the implanted region. Subsequent thermal annealing in a water-saturated oxygen atmosphere at up to 1000.degree. C. produces solid-phase epitaxial regrowth onto the crystalline substrate. A high-quality single crystalline layer results which incorporates the Ti into the crystal structure at much higher concentrations than is possible by standard diffusion techniques, and this implanted region has excellent optical waveguides properties.

  10. Integration of quantum cascade lasers and passive waveguides

    SciTech Connect (OSTI)

    Montoya, Juan Wang, Christine; Goyal, Anish; Creedon, Kevin; Connors, Michael; Daulton, Jeffrey; Donnelly, Joseph; Missaggia, Leo; Aleshire, Chris; Sanchez-Rubio, Antonio; Herzog, William

    2015-07-20

    We report on monolithic integration of active quantum cascade laser (QCL) materials with passive waveguides formed by using proton implantation. Proton implantation reduces the electron concentration in the QCL layers by creating deep levels that trap carriers. This strongly reduces the intersubband absorption and the free-carrier absorption in the gain region and surrounding layers, thus significantly reducing optical loss. We have measured loss as low as α = 0.33 cm{sup −1} in λ = 9.6 μm wavelength proton-implanted QCL material. We have also demonstrated lasing in active-passive integrated waveguides. This simple integration technique is anticipated to enable low-cost fabrication in infrared photonic integrated circuits in the mid-infrared (λ ∼ 3–16 μm)

  11. Waveguide-integrated photonic crystal spectrometer with camera readout

    SciTech Connect (OSTI)

    Meng, Fan; Shiue, Ren-Jye; Li, Luozhou; Nie, Jing; Harris, Nicholas C.; Chen, Edward H.; Schröder, Tim; Englund, Dirk; Wan, Noel; Pervez, Nadia; Kymissis, Ioannis

    2014-08-04

    We demonstrate an infrared spectrometer based on waveguide-coupled nanocavity filters in a planar photonic crystal structure. The input light is coupled into the waveguide, from which spectral components are dropped into the cavities and radiated off-chip for detection on a commercial InGaAs camera. The spectrometer has a footprint of only 60 μm by 8 μm. The spectral resolution is about 1 nm in the operation bandwidth of 1522–1545 nm. By substituting the membrane material and structure parameters, this design can be easily extended into the visible regime and developed for a variety of highly efficient, miniature photonic applications.

  12. Optimizing a waveguide-based sandwich immunoassay for tumor biomarkers

    SciTech Connect (OSTI)

    Mukundan, Harshini; Swanson, Basil I; Xie, Hongzhi; Anderson, Aaron S; Grace, W Kevin; Shively, John E

    2008-01-01

    The sensor team at the Los Alamos National Laboratory has developed a waveguide-based optical biosensor for the detection of biomarkers associated with the disease. We have previously demonstrated the application of this technology to the sensitive detection of carcinoembryonic antigen in serum and nipple aspirate fluid from breast cancer patients. In this publication, we report improvements to this technology that will facilitate transition to a point-of-care diagnostic system and/or robust research tool.

  13. Target molecules detection by waveguiding in a photonic silicon membrane

    DOE Patents [OSTI]

    Letant, Sonia E.; Van Buuren, Anthony; Terminello, Louis; Hart, Bradley R.

    2006-12-26

    Disclosed herein is a porous silicon filter capable of binding and detecting biological and chemical target molecules in liquid or gas samples. A photonic waveguiding silicon filter with chemical and/or biological anchors covalently attached to the pore walls bind target molecules. The system uses transmission curve engineering principles to allow measurements to be made in situ and in real time to detect the presence of various target molecules and calculate the concentration of bound target.

  14. Monolithically integrated solid state laser and waveguide using spin-on glass

    DOE Patents [OSTI]

    Ashby, C.I.H.; Hohimer, J.P.; Neal, D.R.; Vawter, G.A.

    1995-10-31

    A monolithically integrated photonic circuit is disclosed combining a semiconductor source of excitation light with an optically active waveguide formed on the substrate. The optically active waveguide is preferably formed of a spin-on glass to which are added optically active materials which can enable lasing action, optical amplification, optical loss, or frequency conversion in the waveguide, depending upon the added material. 4 figs.

  15. Nanowire photonic crystal waveguides for single-atom trapping and strong light-matter interactions

    SciTech Connect (OSTI)

    Yu, S.-P.; Hood, J. D.; Muniz, J. A.; Martin, M. J.; Hung, C.-L.; Kimble, H. J.; Norte, Richard; Meenehan, Sen M.; Cohen, Justin D.; Painter, Oskar

    2014-03-17

    We present a comprehensive study of dispersion-engineered nanowire photonic crystal waveguides suitable for experiments in quantum optics and atomic physics with optically trapped atoms. Detailed design methodology and specifications are provided, as are the processing steps used to create silicon nitride waveguides of low optical loss in the near-IR. Measurements of the waveguide optical properties and power-handling capability are also presented.

  16. ThreatView

    Energy Science and Technology Software Center (OSTI)

    2007-09-25

    The ThreatView project is based on our prior work with the existing ParaView open-source scientific visualization application. Where ParaView provides a grapical client optimized scientific visualization over the VTK parallel client server architecture, ThreatView provides a client optimized for more generic visual analytics over the same architecture. Because ThreatView is based on the VTK parallel client-server architecture, data sources can reside on remote hosts, and processing and rendering can be performed in parallel. As seenmore » in Fig. 1, ThreatView provides four main methods for visualizing data: Landscape View, which displays a graph using a landscape metaphor where clusters of graph nodes produce "hills" in the landscape; Graph View, which displays a graph using a traditional "ball-and-stick" style; Table View, which displays tabular data in a standard spreadsheet; and Attribute View, which displays a tabular "histogram" of input data - for a selected table column, the Attribute View displays each unique value within the column, and the number of times that value appears in the data. There are two supplemental view types: Text View, which displays tabular data one-record-at-a-time; and the Statistics View, which displays input metadata, such as the number of vertices and edges in a graph, the number of rows in a table, etc.« less

  17. Solitons in nonlinear optics

    SciTech Connect (OSTI)

    Maimistov, Andrei I

    2010-11-13

    The classic examples of optical phenomena resulting in the appearance of solitons are self-focusing, self-induced transparency, and parametric three-wave interaction. To date, the list of the fields of nonlinear optics and models where solitons play an important role has significantly expanded. Now long-lived or stable solitary waves are called solitons, including, for example, dissipative, gap, parametric, and topological solitons. This review considers nonlinear optics models giving rise to the appearance of solitons in a narrow sense: solitary waves corresponding to the solutions of completely integrable systems of equations basic for the models being discussed. (review)

  18. Geometrical tuning art for entirely subwavelength grating waveguide based integrated photonics circuits

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

    Wang, Zheng; Xu, Xiaochuan; Fan, Donglei; Wang, Yaguo; Subbaraman, Harish; Chen, Ray T.

    2016-05-05

    Here, subwavelength grating (SWG) waveguide is an intriguing alternative to conventional optical waveguides due to the extra degree of freedom it offers in tuning a few important waveguide properties, such as dispersion and refractive index. Devices based on SWG waveguides have demonstrated impressive performances compared to conventional waveguides. However, the high loss of SWG waveguide bends jeopardizes their applications in integrated photonic circuits. In this work, we propose a geometrical tuning art, which realizes a pre-distorted refractive index profile in SWG waveguide bends. The pre-distorted refractive index profile can effectively reduce the mode mismatch and radiation loss simultaneously, thus significantlymore » reduce the bend loss. This geometry tuning art has been numerically optimized and experimentally demonstrated in present study. Through such tuning, the average insertion loss of a 5 μm SWG waveguide bend is reduced drastically from 5.43 dB to 1.10 dB per 90° bend for quasi-TE polarization. In the future, the proposed scheme will be utilized to enhance performance of a wide range of SWG waveguide based photonics devices.« less

  19. Terahertz emission from a two-color plasma filament in a slot waveguide

    SciTech Connect (OSTI)

    Dietze, D.; Unterrainer, K.; Darmo, J.

    2012-02-27

    Terahertz emission in forward direction from a long two-color filament placed in the center of a slot waveguide is reported. The waveguide improves the collection and imaging of the generated THz radiation. By tuning the plate separation and position of the waveguide along the filament axis, the emitted mode can be matched to the collection optics. We achieved an increase of the detected electric field by 40% and of the THz pulse energy by four times compared to the case without waveguide.

  20. Universal nonlinear entanglement witnesses

    SciTech Connect (OSTI)

    Kotowski, Marcin; Kotowski, Michal [College of Inter-Faculty Individual Studies in Mathematics and Natural Sciences, Warsaw University, PL-Warszawa (Poland); Center for Theoretical Physics, Polish Academy of Sciences, Aleja Lotnikow 32/44, PL-02-668 Warszawa (Poland); Kus, Marek [Center for Theoretical Physics, Polish Academy of Sciences, Aleja Lotnikow 32/44, PL-02-668 Warszawa (Poland)

    2010-06-15

    We give a universal recipe for constructing nonlinear entanglement witnesses able to detect nonclassical correlations in arbitrary systems of distinguishable and/or identical particles for an arbitrary number of constituents. The constructed witnesses are expressed in terms of expectation values of observables. As such, they are, at least in principle, measurable in experiments.

  1. Intramolecular and nonlinear dynamics

    SciTech Connect (OSTI)

    Davis, M.J.

    1993-12-01

    Research in this program focuses on three interconnected areas. The first involves the study of intramolecular dynamics, particularly of highly excited systems. The second area involves the use of nonlinear dynamics as a tool for the study of molecular dynamics and complex kinetics. The third area is the study of the classical/quantum correspondence for highly excited systems, particularly systems exhibiting classical chaos.

  2. Nonlinear and Nonideal MHD

    SciTech Connect (OSTI)

    Callen, J. D.

    2002-11-04

    The primary efforts this year have focused on exploring the nonlinear evolution of localized interchange instabilities, some extensions of neoclassical tearing mode theory, and developing a model for the dynamic electrical conductivity in a bumpy cylinder magnetic field. In addition, we have vigorously participated in the computationally-focused NIMROD and CEMM projects.

  3. Nonlinear terahertz superconducting plasmonics

    SciTech Connect (OSTI)

    Wu, Jingbo; Liang, Lanju; Jin, Biaobing E-mail: tonouchi@ile.osaka-u.ac.jp Kang, Lin; Xu, Weiwei; Chen, Jian; Wu, Peiheng E-mail: tonouchi@ile.osaka-u.ac.jp; Zhang, Caihong; Kawayama, Iwao; Murakami, Hironaru; Tonouchi, Masayoshi E-mail: tonouchi@ile.osaka-u.ac.jp; Wang, Huabing

    2014-10-20

    Nonlinear terahertz (THz) transmission through subwavelength hole array in superconducting niobium nitride (NbN) film is experimentally investigated using intense THz pulses. The good agreement between the measurement and numerical simulations indicates that the field strength dependent transmission mainly arises from the nonlinear properties of the superconducting film. Under weak THz pulses, the transmission peak can be tuned over a frequency range of 145 GHz which is attributed to the high kinetic inductance of 50?nm-thick NbN film. Utilizing the THz pump-THz probe spectroscopy, we study the dynamic process of transmission spectra and demonstrate that the transition time of such superconducting plasmonic device is within 5 ps.

  4. Fabrication and characterization of submicron polymer waveguides by micro-transfer molding

    SciTech Connect (OSTI)

    Wu, Te-Wei

    2009-12-15

    Various methods exist for fabrication of micron and submicron sized waveguide structures. However, most of them include expensive and time consuming semiconductor fabrication techniques. An economical method for fabricating waveguide structures is introduced and demonstrated in this thesis. This method is established based on previously well-developed photonic crystal fabrication method called two-polymer microtransfer molding. The waveguide in this work functions by a coupler structure that diffracts the incident light into submicron polymer rods. The light is then guided through the rods. Characterization is done by collecting the light that has been guided through the waveguide and exits the end of these submicron polymer bars. The coupling and waveguiding capabilities are demonstrated using two light sources, a laser and white light.

  5. Zero-mode clad waveguides for performing spectroscopy with confined effective observation volumes

    DOE Patents [OSTI]

    Levene, Michael J.; Korlach, Jonas; Turner, Stephen W.; Craighead, Harold G.; Webb, Watt W.

    2005-07-12

    The present invention is directed to a method and an apparatus for analysis of an analyte. The method involves providing a zero-mode waveguide which includes a cladding surrounding a core where the cladding is configured to preclude propagation of electromagnetic energy of a frequency less than a cutoff frequency longitudinally through the core of the zero-mode waveguide. The analyte is positioned in the core of the zero-mode waveguide and is then subjected, in the core of the zero-mode waveguide, to activating electromagnetic radiation of a frequency less than the cut-off frequency under conditions effective to permit analysis of the analyte in an effective observation volume which is more compact than if the analysis were carried out in the absence of the zero-mode waveguide.

  6. Plasma expansion into a waveguide created by a linearly polarized femtosecond laser pulse

    SciTech Connect (OSTI)

    Lemos, N.; Grismayer, T.; Cardoso, L.; Figueira, G.; Dias, J. M.

    2013-06-15

    We demonstrate the efficient generation of 4 mm and 8 mm long plasma waveguides in hydrogen and helium. These waveguides have matching spots sizes for 13 to 34 ?m laser beams. The plasma waveguides are created by ultra-short laser pulses (sub-picosecond) of moderate intensities, ?10{sup 15}10{sup 16} W cm{sup ?2}, that heat the plasma to initial temperatures of tens of eV in order to create a hot plasma column that will expand into a plasma waveguide. We have determined that the main heating mechanism when using fs laser pulses and plasma densities ?10{sup 1819} cm{sup ?3} is Above Threshold Ionization. Detailed time and space electron density measurements are presented for the laser produced plasma waveguides.

  7. Microsphere-chain waveguides: Focusing and transport properties

    SciTech Connect (OSTI)

    Allen, Kenneth W., E-mail: kallen62@uncc.edu; Astratov, Vasily N., E-mail: astratov@uncc.edu [Department of Physics and Optical Science, Center for Optoelectronics and Optical Communications, University of North Carolina at Charlotte, Charlotte, North Carolina 28223-0001 (United States); Air Force Research Laboratory, Sensors Directorate, Wright Patterson AFB, Ohio 45433 (United States); Darafsheh, Arash; Abolmaali, Farzaneh [Department of Physics and Optical Science, Center for Optoelectronics and Optical Communications, University of North Carolina at Charlotte, Charlotte, North Carolina 28223-0001 (United States); Mojaverian, Neda; Limberopoulos, Nicholaos I. [Air Force Research Laboratory, Sensors Directorate, Wright Patterson AFB, Ohio 45433 (United States); Lupu, Anatole [Institut d'Electronique Fondamentale, UMR 8622 CNRS, Universite Paris-Sud XI, 91405 Orsay (France)

    2014-07-14

    It is shown that the focusing properties of polystyrene microsphere-chain waveguides (MCWs) formed by sufficiently large spheres (D???20?, where D is the sphere diameter and ? is the wavelength of light) scale with the sphere diameter as predicted by geometrical optics. However, this scaling behavior does not hold for mesoscale MCWs with D???10? resulting in a periodical focusing with gradually reducing beam waists and in extremely small propagation losses. The observed effects are related to properties of nanojet-induced and periodically focused modes in such structures. The results can be used for developing focusing microprobes, laser scalpels, and polarization filters.

  8. Laser illumination of multiple capillaries that form a waveguide

    DOE Patents [OSTI]

    Dhadwal, Harbans S.; Quesada, Mark A.; Studier, F. William

    1998-08-04

    A system and method are disclosed for efficient laser illumination of the interiors of multiple capillaries simultaneously, and collection of light emitted from them. Capillaries in a parallel array can form an optical waveguide wherein refraction at the cylindrical surfaces confines side-on illuminating light to the core of each successive capillary in the array. Methods are provided for determining conditions where capillaries will form a waveguide and for assessing and minimizing losses due to reflection. Light can be delivered to the arrayed capillaries through an integrated fiber optic transmitter or through a pair of such transmitters aligned coaxially at opposite sides of the array. Light emitted from materials within the capillaries can be carried to a detection system through optical fibers, each of which collects light from a single capillary, with little cross talk between the capillaries. The collection ends of the optical fibers can be in a parallel array with the same spacing as the capillary array, so that the collection fibers can all be aligned to the capillaries simultaneously. Applicability includes improving the efficiency of many analytical methods that use capillaries, including particularly high-throughput DNA sequencing and diagnostic methods based on capillary electrophoresis.

  9. Laser illumination of multiple capillaries that form a waveguide

    DOE Patents [OSTI]

    Dhadwal, H.S.; Quesada, M.A.; Studier, F.W.

    1998-08-04

    A system and method are disclosed for efficient laser illumination of the interiors of multiple capillaries simultaneously, and collection of light emitted from them. Capillaries in a parallel array can form an optical waveguide wherein refraction at the cylindrical surfaces confines side-on illuminating light to the core of each successive capillary in the array. Methods are provided for determining conditions where capillaries will form a waveguide and for assessing and minimizing losses due to reflection. Light can be delivered to the arrayed capillaries through an integrated fiber optic transmitter or through a pair of such transmitters aligned coaxially at opposite sides of the array. Light emitted from materials within the capillaries can be carried to a detection system through optical fibers, each of which collects light from a single capillary, with little cross talk between the capillaries. The collection ends of the optical fibers can be in a parallel array with the same spacing as the capillary array, so that the collection fibers can all be aligned to the capillaries simultaneously. Applicability includes improving the efficiency of many analytical methods that use capillaries, including particularly high-throughput DNA sequencing and diagnostic methods based on capillary electrophoresis. 35 figs.

  10. Methods and apparatus for vertical coupling from dielectric waveguides

    DOE Patents [OSTI]

    Yaacobi, Ami; Cordova, Brad Gilbert

    2014-06-17

    A frequency-chirped nano-antenna provides efficient sub-wavelength vertical emission from a dielectric waveguide. In one example, this nano-antenna includes a set of plasmonic dipoles on the opposite side of a SiYV.sub.4 waveguide from a ground plane. The resulting structure, which is less than half a wavelength long, emits a broadband beam (e.g., >300 nm) that can be coupled into an optical fiber. In some embodiments, a diffractive optical element with unevenly shaped regions of high- and low-index dielectric material collimates the broadband beam for higher coupling efficiency. In some cases, a negative lens element between the nano-antenna and the diffractive optical element accelerates the emitted beam's divergence (and improves coupling efficiency), allowing for more compact packaging. Like the diffractive optical element, the negative lens element includes unevenly shaped regions of high- and low-index dielectric material that can be designed to compensate for aberrations in the beam emitted by the nano-antenna.

  11. Slow wave structures using twisted waveguides for charged particle applications

    DOE Patents [OSTI]

    Kang, Yoon W.; Fathy, Aly E.; Wilson, Joshua L.

    2012-12-11

    A rapidly twisted electromagnetic accelerating structure includes a waveguide body having a central axis, one or more helical channels defined by the body and disposed around a substantially linear central axial channel, with central portions of the helical channels merging with the linear central axial channel. The structure propagates electromagnetic waves in the helical channels which support particle beam acceleration in the central axial channel at a phase velocity equal to or slower than the speed of light in free space. Since there is no variation in the shape of the transversal cross-section along the axis of the structure, inexpensive mechanical fabrication processes can be used to form the structure, such as extrusion, casting or injection molding. Also, because the field and frequency of the resonant mode depend on the whole structure rather than on dimensional tolerances of individual cells, no tuning of individual cells is needed. Accordingly, the overall operating frequency may be varied with a tuning/phase shifting device located outside the resonant waveguide structure.

  12. Integration of a terahertz quantum cascade laser with a hollow waveguide

    SciTech Connect (OSTI)

    Wanke, Michael C.; Nordquist, Christopher D.

    2012-07-03

    The present invention is directed to the integration of a quantum cascade laser with a hollow waveguide on a chip to improve both the beam pattern and manufacturability. By coupling the QCL output into a single-mode rectangular waveguide the radiation mode structure can be known and the propagation, manipulation, and broadcast of the QCL radiation can then be entirely controlled by well-established rectangular waveguide techniques. By controlling the impedance of the interface, enhanced functions, such as creating amplifiers, efficient coupling to external cavities, and increasing power output from metal-metal THz QCLs, are also enabled.

  13. Optical characterization of femtosecond laser induced active channel waveguides in lithium fluoride crystals

    SciTech Connect (OSTI)

    Chiamenti, I.; Kalinowski, H. J.; Bonfigli, F.; Montereali, R. M.; Gomes, A. S. L.; Michelotti, F.

    2014-01-14

    We successfully realized broad-band light-emitting color center waveguides buried in LiF crystals by using femtosecond laser pulses. The characterization of the waveguides was performed by optical microscopy, photoluminescence spectra, loss measurements and near-field profiling. The experimental results show that the direct-writing fabrication process induces low-index contrast active channel waveguides: their wavelength-dependent refractive index changes, estimated from 10{sup −3} to 10{sup −4} depending on the writing conditions, allow supporting few modes at visible and near-infrared wavelengths.

  14. Taking the long view

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

    Taking the long view Taking the long view on environmental stewardship A newly articulated mission for environmental stewardship at the Laboratory can be summed up in a simple phrase: clean up the past, control current operations, and create a sustainable future. March 20, 2012 Los Alamos Aerial Aerial view of a canyon in Los Alamos, New Mexico. Contact Environmental Communication & Public Outreach P.O. Box 1663 MS M996 Los Alamos, NM 87545 (505) 667-0216 Email "The future viability of

  15. Beam manipulation and acceleration with Dielectric-Lined Waveguides

    SciTech Connect (OSTI)

    Lemery, Francois

    2015-06-01

    The development of next-generation TeV+ electron accelerators will require either immense footprints based on conventional acceleraton techniques or the development of new higher{gradient acceleration methods. One possible alternative is beam-driven acceleration in a high-impedance medium such as a dielectric-lined-waveguide (DLW), where a highcharge bunch passes through a DLW and can excite gradients on the order of GV/m. An important characteristic of this acceleration class is the transformer ratio which characterizes the energy transfer of the scheme. This dissertation discusses alternative methods to improve the transformer ratio for beam-driven acceleration and also considers the use of DLWs for beam manipulation at low energy.

  16. Direct-patterned optical waveguides on amorphous silicon films

    DOE Patents [OSTI]

    Vernon, Steve; Bond, Tiziana C.; Bond, Steven W.; Pocha, Michael D.; Hau-Riege, Stefan

    2005-08-02

    An optical waveguide structure is formed by embedding a core material within a medium of lower refractive index, i.e. the cladding. The optical index of refraction of amorphous silicon (a-Si) and polycrystalline silicon (p-Si), in the wavelength range between about 1.2 and about 1.6 micrometers, differ by up to about 20%, with the amorphous phase having the larger index. Spatially selective laser crystallization of amorphous silicon provides a mechanism for controlling the spatial variation of the refractive index and for surrounding the amorphous regions with crystalline material. In cases where an amorphous silicon film is interposed between layers of low refractive index, for example, a structure comprised of a SiO.sub.2 substrate, a Si film and an SiO.sub.2 film, the formation of guided wave structures is particularly simple.

  17. Application of Plasma Waveguides to High Energy Accelerators

    SciTech Connect (OSTI)

    Milchberg, Howard M

    2013-03-30

    The eventual success of laser-plasma based acceleration schemes for high-energy particle physics will require the focusing and stable guiding of short intense laser pulses in reproducible plasma channels. For this goal to be realized, many scientific issues need to be addressed. These issues include an understanding of the basic physics of, and an exploration of various schemes for, plasma channel formation. In addition, the coupling of intense laser pulses to these channels and the stable propagation of pulses in the channels require study. Finally, new theoretical and computational tools need to be developed to aid in the design and analysis of experiments and future accelerators. Here we propose a 3-year renewal of our combined theoretical and experimental program on the applications of plasma waveguides to high-energy accelerators. During the past grant period we have made a number of significant advances in the science of laser-plasma based acceleration. We pioneered the development of clustered gases as a new highly efficient medium for plasma channel formation. Our contributions here include theoretical and experimental studies of the physics of cluster ionization, heating, explosion, and channel formation. We have demonstrated for the first time the generation of and guiding in a corrugated plasma waveguide. The fine structure demonstrated in these guides is only possible with cluster jet heating by lasers. The corrugated guide is a slow wave structure operable at arbitrarily high laser intensities, allowing direct laser acceleration, a process we have explored in detail with simulations. The development of these guides opens the possibility of direct laser acceleration, a true miniature analogue of the SLAC RF-based accelerator. Our theoretical studies during this period have also contributed to the further development of the simulation codes, Wake and QuickPIC, which can be used for both laser driven and beam driven plasma based acceleration schemes. We

  18. Taking the long view

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

    2012 Los Alamos Aerial Aerial view of a canyon in Los Alamos, New Mexico. Contact Environmental Communication & Public Outreach P.O. Box 1663 MS M996 Los Alamos, NM 87545 (505)...

  19. ParaView

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

    ... program in step 4 above. 1. Open ParaView and select File->Connect from the menu. 5. The server config script will start an xterm allowing you to login to the selected system. ...

  20. Push-pull radio frequency circuit with integral transistion to waveguide output

    DOE Patents [OSTI]

    Bennett, Wilfred P.

    1987-01-01

    A radio frequency circuit for ICRF heating includes a resonant push-pull circuit, a double ridged rectangular waveguide, and a coupling transition which joins the waveguide to the resonant circuit. The resonant circuit includes two cylindrical conductors mounted side by side and two power vacuum tubes attached to respective ends of a cylindrical conductor. A conductive yoke is located at the other end of the cylindrical conductors to short circuit the two cylindrical conductors. The coupling transition includes two relatively flat rectangular conductors extending perpendicular to the longitudinal axes of a respective cylindrical conductor to which the flat conductor is attached intermediate the ends thereof. Conductive side covers and end covers are also provided for forming pockets in the waveguide into which the flat conductors extend when the waveguide is attached to a shielding enclosure surrounding the resonant circuit.

  1. Dispersion and interaction of waveguide modes in a relativistic electron beam with ion-channel guiding

    SciTech Connect (OSTI)

    Maraghechi, Borna; Maraghechi, Behrouz

    2008-07-15

    A theory for the high-frequency eigenmodes of a cylindrical metallic waveguide partially filled with a relativistic electron beam and guided by an ion channel is presented. Equations that permit calculation of dispersion curves for five families of wave modes are derived. The dependence of the frequencies and the dispersion curves of azimuthally asymmetric modes on the ratio of the beam radius a to the waveguide radius R are studied in detail. The coupling of the dispersion curves of different modes is studied and illustrated for the partially filled waveguide. It was found that, in their course of interaction, HE modes cannot displace the betatron modes in a completely filled waveguide, which is different from the case of a magnetized electron beam. Physical and analytical explanations are presented for this difference.

  2. Waveguide-based Ultrasonic and Far-field Electromagnetic Sensors for Downhole Reservoir Characterization

    Broader source: Energy.gov [DOE]

    Project objective: To develop waveguide-based ultrasonic and farfield electromagnetic sensors to measure key Enhanced Geothermal Systems (EGS) reservoir parameters, including directional temperature, pressure, fluidflow, fracture imaging, and flow/rock interaction.

  3. Planar optical waveguides for optical panel having gradient refractive index core

    DOE Patents [OSTI]

    Veligdan, James T.

    2004-08-24

    An optical panel is disclosed. A plurality of stacked planar optical waveguides are used to guide light from an inlet face to an outlet face of an optical panel. Each of the optical waveguides comprises a planar sheet of core material having a central plane. The core material has an index of refraction which decreases as the distance from the central plane increases. The decrease in the index of refraction occurs gradually and continuously.

  4. Planar optical waveguides for optical panel having gradient refractive index core

    DOE Patents [OSTI]

    Veligdan, James T.

    2001-01-01

    An optical panel is disclosed. A plurality of stacked planar optical waveguides are used to guide light from an inlet face to an outlet face of an optical panel. Each of the optical waveguides comprises a planar sheet of core material having a central plane. The core material has an index of refraction which decreases as the distance from the central plane increases. The decrease in the index of refraction occurs gradually and continuously.

  5. Planar Optical Waveguide Coupler Transformers for High-Power Solar Enegy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Collection and Transmission | Department of Energy Planar Optical Waveguide Coupler Transformers for High-Power Solar Enegy Collection and Transmission Planar Optical Waveguide Coupler Transformers for High-Power Solar Enegy Collection and Transmission This presentation was delivered at the SunShot Concentrating Solar Power (CSP) Program Review 2013, held April 23-25, 2013 near Phoenix, Arizona. csp_review_meeting_042313_kobayashi.pdf (1.39 MB) More Documents & Publications Chemically

  6. Corrigendum and addendum. Modeling weakly nonlinear acoustic...

    Office of Scientific and Technical Information (OSTI)

    Corrigendum and addendum. Modeling weakly nonlinear acoustic wave propagation Citation Details In-Document Search Title: Corrigendum and addendum. Modeling weakly nonlinear ...

  7. Nonlinear vibrational microscopy

    DOE Patents [OSTI]

    Holtom, Gary R.; Xie, Xiaoliang Sunney; Zumbusch, Andreas

    2000-01-01

    The present invention is a method and apparatus for microscopic vibrational imaging using coherent Anti-Stokes Raman Scattering or Sum Frequency Generation. Microscopic imaging with a vibrational spectroscopic contrast is achieved by generating signals in a nonlinear optical process and spatially resolved detection of the signals. The spatial resolution is attained by minimizing the spot size of the optical interrogation beams on the sample. Minimizing the spot size relies upon a. directing at least two substantially co-axial laser beams (interrogation beams) through a microscope objective providing a focal spot on the sample; b. collecting a signal beam together with a residual beam from the at least two co-axial laser beams after passing through the sample; c. removing the residual beam; and d. detecting the signal beam thereby creating said pixel. The method has significantly higher spatial resolution then IR microscopy and higher sensitivity than spontaneous Raman microscopy with much lower average excitation powers. CARS and SFG microscopy does not rely on the presence of fluorophores, but retains the resolution and three-dimensional sectioning capability of confocal and two-photon fluorescence microscopy. Complementary to these techniques, CARS and SFG microscopy provides a contrast mechanism based on vibrational spectroscopy. This vibrational contrast mechanism, combined with an unprecedented high sensitivity at a tolerable laser power level, provides a new approach for microscopic investigations of chemical and biological samples.

  8. Reconstruction of nonlinear wave propagation

    DOE Patents [OSTI]

    Fleischer, Jason W; Barsi, Christopher; Wan, Wenjie

    2013-04-23

    Disclosed are systems and methods for characterizing a nonlinear propagation environment by numerically propagating a measured output waveform resulting from a known input waveform. The numerical propagation reconstructs the input waveform, and in the process, the nonlinear environment is characterized. In certain embodiments, knowledge of the characterized nonlinear environment facilitates determination of an unknown input based on a measured output. Similarly, knowledge of the characterized nonlinear environment also facilitates formation of a desired output based on a configurable input. In both situations, the input thus characterized and the output thus obtained include features that would normally be lost in linear propagations. Such features can include evanescent waves and peripheral waves, such that an image thus obtained are inherently wide-angle, farfield form of microscopy.

  9. Studies of Nonlinear Problems. I

    DOE R&D Accomplishments [OSTI]

    Fermi, E.; Pasta, J.; Ulam, S.

    1955-05-01

    A one-dimensional dynamical system of 64 particles with forces between neighbors containing nonlinear terms has been studied on the Los Alamos computer MANIAC I. The nonlinear terms considered are quadratic, cubic, and broken linear types. The results are analyzed into Fourier components and plotted as a function of time. The results show very little, if any, tendency toward equipartition of energy among the degrees of freedom.

  10. Stabilization of solitons under competing nonlinearities by external potentials

    SciTech Connect (OSTI)

    Zegadlo, Krzysztof B. Karpierz, Miroslaw A.; Wasak, Tomasz; Trippenbach, Marek; Malomed, Boris A.

    2014-12-15

    We report results of the analysis for families of one-dimensional (1D) trapped solitons, created by competing self-focusing (SF) quintic and self-defocusing (SDF) cubic nonlinear terms. Two trapping potentials are considered, the harmonic-oscillator (HO) and delta-functional ones. The models apply to optical solitons in colloidal waveguides and other photonic media, and to matter-wave solitons in Bose-Einstein condensates loaded into a quasi-1D trap. For the HO potential, the results are obtained in an approximate form, using the variational and Thomas-Fermi approximations, and in a full numerical form, including the ground state and the first antisymmetric excited one. For the delta-functional attractive potential, the results are produced in a fully analytical form, and verified by means of numerical methods. Both exponentially localized solitons and weakly localized trapped modes are found for the delta-functional potential. The most essential conclusions concern the applicability of competing Vakhitov-Kolokolov (VK) and anti-VK criteria to the identification of the stability of solitons created under the action of the competing SF and SDF terms.

  11. Foundations of nonlinear gyrokinetic theory

    SciTech Connect (OSTI)

    Brizard, A. J.; Hahm, T. S.

    2007-04-15

    Nonlinear gyrokinetic equations play a fundamental role in our understanding of the long-time behavior of strongly magnetized plasmas. The foundations of modern nonlinear gyrokinetic theory are based on three pillars: (i) a gyrokinetic Vlasov equation written in terms of a gyrocenter Hamiltonian with quadratic low-frequency ponderomotivelike terms, (ii) a set of gyrokinetic Maxwell (Poisson-Ampere) equations written in terms of the gyrocenter Vlasov distribution that contain low-frequency polarization (Poisson) and magnetization (Ampere) terms, and (iii) an exact energy conservation law for the gyrokinetic Vlasov-Maxwell equations that includes all the relevant linear and nonlinear coupling terms. The foundations of nonlinear gyrokinetic theory are reviewed with an emphasis on rigorous application of Lagrangian and Hamiltonian Lie-transform perturbation methods in the variational derivation of nonlinear gyrokinetic Vlasov-Maxwell equations. The physical motivations and applications of the nonlinear gyrokinetic equations that describe the turbulent evolution of low-frequency electromagnetic fluctuations in a nonuniform magnetized plasmas with arbitrary magnetic geometry are discussed.

  12. Acceleration and dynamics of an electron in the degenerate and magnetized plasma elliptical waveguide

    SciTech Connect (OSTI)

    Abdoli-Arani, A.; Jazi, B. [Department of Photonics, Faculty of Physics, University of Kashan, Kashan (Iran, Islamic Republic of); Shokri, B. [Physics Department and Laser-Plasma Research Institute, G. C. Shahid Beheshti University, Tehran (Iran, Islamic Republic of)

    2013-02-15

    The dynamics and energy gain of an electron in the field of a transverse magnetic wave propagating inside an elliptical degenerate plasma waveguide is analytically investigated by finding the field components of the TM{sub mr} mode in this waveguide. Besides, by solving the relativistic momentum and energy equations the deflection angle and the acceleration gradient of the electron in the waveguide are obtained. Furthermore, the field components of the hybrid mode and the transferred power in the presence of the magnetic field in this waveguide are found. Also by applying the boundary conditions at the plasma-conductor interface, we calculate the dispersion relation. It is shown that the cutoff frequency of this mode is dependent on the plasma density but independent of the magnetic field. Then, a single-electron model for numerical calculations of the electron deflection angle and acceleration gradient inside the magnetized plasma-filled elliptical waveguide is generally presented to be used as a cascading process for the acceleration purposes.

  13. REACTOR VIEWING APPARATUS

    DOE Patents [OSTI]

    Monk, G.S.

    1959-01-13

    An optical system is presented that is suitable for viewing objects in a region of relatively high radioactivity, or high neutron activity, such as a neutronic reactor. This optical system will absorb neutrons and gamma rays thereby protecting personnel fronm the harmful biological effects of such penetrating radiations. The optical system is comprised of a viewing tube having a lens at one end, a transparent solid member at the other end and a transparent aqueous liquid completely filling the tube between the ends. The lens is made of a polymerized organic material and the transparent solid member is made of a radiation absorbent material. A shield surrounds the tube betwcen the flanges and is made of a gamma ray absorbing material.

  14. Stereoscopic optical viewing system

    DOE Patents [OSTI]

    Tallman, C.S.

    1986-05-02

    An improved optical system which provides the operator with a stereoscopic viewing field and depth of vision, particularly suitable for use in various machines such as electron or laser beam welding and drilling machines. The system features two separate but independently controlled optical viewing assemblies from the eyepiece to a spot directly above the working surface. Each optical assembly comprises a combination of eye pieces, turning prisms, telephoto lenses for providing magnification, achromatic imaging relay lenses and final stage pentagonal turning prisms. Adjustment for variations in distance from the turning prisms to the workpiece, necessitated by varying part sizes and configurations and by the operator's visual accuity, is provided separately for each optical assembly by means of separate manual controls at the operator console or within easy reach of the operator.

  15. Stereoscopic optical viewing system

    DOE Patents [OSTI]

    Tallman, Clifford S.

    1987-01-01

    An improved optical system which provides the operator a stereoscopic viewing field and depth of vision, particularly suitable for use in various machines such as electron or laser beam welding and drilling machines. The system features two separate but independently controlled optical viewing assemblies from the eyepiece to a spot directly above the working surface. Each optical assembly comprises a combination of eye pieces, turning prisms, telephoto lenses for providing magnification, achromatic imaging relay lenses and final stage pentagonal turning prisms. Adjustment for variations in distance from the turning prisms to the workpiece, necessitated by varying part sizes and configurations and by the operator's visual accuity, is provided separately for each optical assembly by means of separate manual controls at the operator console or within easy reach of the operator.

  16. NONLINEAR COLOR-METALLICITY RELATIONS OF GLOBULAR CLUSTERS. V. NONLINEAR ABSORPTION-LINE INDEX VERSUS METALLICITY RELATIONS AND BIMODAL INDEX DISTRIBUTIONS OF M31 GLOBULAR CLUSTERS

    SciTech Connect (OSTI)

    Kim, Sooyoung; Yoon, Suk-Jin; Chung, Chul; Lee, Young-Wook; Caldwell, Nelson; Schiavon, Ricardo P.; Kang, Yongbeom; Rey, Soo-Chang

    2013-05-10

    Recent spectroscopy on the globular cluster (GC) system of M31 with unprecedented precision witnessed a clear bimodality in absorption-line index distributions of old GCs. Such division of extragalactic GCs, so far asserted mainly by photometric color bimodality, has been viewed as the presence of merely two distinct metallicity subgroups within individual galaxies and forms a critical backbone of various galaxy formation theories. Given that spectroscopy is a more detailed probe into stellar population than photometry, the discovery of index bimodality may point to the very existence of dual GC populations. However, here we show that the observed spectroscopic dichotomy of M31 GCs emerges due to the nonlinear nature of metallicity-to-index conversion and thus one does not necessarily have to invoke two separate GC subsystems. We take this as a close analogy to the recent view that metallicity-color nonlinearity is primarily responsible for observed GC color bimodality. We also demonstrate that the metallicity-sensitive magnesium line displays non-negligible metallicity-index nonlinearity and Balmer lines show rather strong nonlinearity. This gives rise to bimodal index distributions, which are routinely interpreted as bimodal metallicity distributions, not considering metallicity-index nonlinearity. Our findings give a new insight into the constitution of M31's GC system, which could change much of the current thought on the formation of GC systems and their host galaxies.

  17. COMPUTER SIMULATIONS OF WAVEGUIDE WINDOW AND COUPLER IRIS FOR PRECISION MATCHING

    SciTech Connect (OSTI)

    Lee, Sung-Woo; Kang, Yoon W; Shin, Ki; Vassioutchenko, Alexandre V

    2011-01-01

    A tapered ridge waveguide iris input coupler and a waveguide ceramic disk windows are used on each of six drift tube linac (DTL) cavities in the Spallation Neutron Source (SNS). The coupler design employs rapidly tapered double ridge waveguide to reduce the cross section down to a smaller low impedance transmission line section that can couple to the DTL tank easily. The impedance matching is done by adjusting the dimensions of the thin slit aperture between the ridges that is the coupling element responsible for the power delivery to the cavity. Since the coupling is sensitive to the dimensional changes of the aperture, it requires careful tuning for precise matching. Accurate RF simulation using latest 3-D EM code is desirable to help the tuning for maintenance and spare manufacturing. Simulations are done for the complete system with the ceramic window and the coupling iris on the cavity to see mutual interaction between the components as a whole.

  18. Further developments of capillary absorption spectrometers using small hollow-waveguide fibers

    SciTech Connect (OSTI)

    Kelly, James F.; Sams, Robert L.; Blake, Thomas A.; Kriesel, Jason M.

    2014-05-01

    Our objective is to enhance quantification of stable carbon and oxygen isotope ratios to better than 1 relative isotope precision for sample sizes < 1 pico-mole. A newer variant Capillary Absorption Spectrometer (CAS) is described using a proprietary linear-taper hollow waveguide in conjunction with wavelength and frequency modulation techniques of tunable laser absorption spectrometry. Previous work used circular capillaries with uniform 1 mm ID to measure 13C/12C ratios with ? 20 pico-mole samples to ? 10 ppm (1 precision against standards) [1]. While performing fairly well, it generated residual modal noise due to multipath propagation in the hollow-waveguides (HWGs). This system has been utilized with laser ablation-catalytic combustion techniques to analyze small resolution (~ 25 ?m spot diameter) laser ablation events on solids. Using smaller ID capillary waveguides could improve detection limits and spatial resolutions. Reducing an IR compatible hollow waveguides inner diameter (ID) to < 300 ?m, reduces modal noise significantly for mid-IR operation, but feedback noise with high gain semiconductor lasers can become problematic. A proprietary linear-taper small waveguide (mean ID = 0.35 mm, L = 1 m) was tested to understand whether modal noise and optical feedback effects could be simultaneously reduced. We see better mode filtering and, significant reductions of feedback noise under favorable coupling of a multi-spatial mode QC laser to the smaller ID of the linear-tapered HWG. We demonstrate that better modal coupling operation is consistent with Liouvilles theorem, where greater suppression of feedback from spurious scatter within the HWG occurs by injecting the laser into the smaller ID port. Our progress on developing lighter weight, potentially fieldable alternatives to Isotope Ratio Mass Spectrometers (IRMS) with a small volume (? 0.1 cm3) CAS system will be discussed and compared to other competitive systems.

  19. Disorder-induced transparency in a one-dimensional waveguide side coupled with optical cavities

    SciTech Connect (OSTI)

    Zhang, Yongyou Dong, Guangda; Zou, Bingsuo

    2014-05-07

    Disorder influence on photon transmission behavior is theoretically studied in a one-dimensional waveguide side coupled with a series of optical cavities. For this sake, we propose a concept of disorder-induced transparency appearing on the low-transmission spectral background. Two kinds of disorders, namely, disorders of optical cavity eigenfrequencies and relative phases in the waveguide side coupled with optical cavities are considered to show the disorder-induced transparency. They both can induce the optical transmission peaks on the low-transmission backgrounds. The statistical mean value of the transmission also increases with increasing the disorders of the cavity eigenfrequencies and relative phases.

  20. The View from HQ

    National Nuclear Security Administration (NNSA)

    A publication of the Office of Advanced Simulation & Computing, NNSA Defense Programs NA-ASC-500-07-Issue 3 May 2007 The View from HQ by Dimitri Kusnezov I have been spending much of my time these days thinking about science, technology and engineering and the role of the laboratories and how that will be reflected in the Complex of the future. This is on my mind for two reasons: one is my responsibility to produce a science and technology roadmap for Complex 2030-Defense Program's vision

  1. The BetterBuildings View

    Broader source: Energy.gov [DOE]

    The BetterBuildings View Newsletter, April 2011, from the U.S. Department of Energy's Better Buildings Neighborhood Program.

  2. Nonlinear analysis of composite laminates

    SciTech Connect (OSTI)

    Chen, J.

    1984-01-01

    Nonlinear static and dynamic responses of composite laminates were investigated using the finite element method. A nine-node isoparametric quadrilateral element was developed to formulate the finite element equations for a laminated plate under initial deformations and initial stresses according to the Mindlin plate theory and von Karman large deflection assumptions. Static large deflection and postbuckling of plates, impact response of a laminate under initial stresses, free vibration and impact response of buckled composite plates, and non-linear transient and impact analyses of laminated plates with/without initial stresses were studied. In the impact analysis, a experimentally established contact law that accounts for the permanent indentation was employed to calculate the contact force. This contact law was incorporated into the finite element program to study the dynamic response of laminated composites subjected to impact of a hard object. In the nonlinear transient analysis, Newmark time integration algorithm, in conjunction with successive iterations within each time step was used. An iteration scheme with a constant coefficient matrix was used to treat the nonlinear terms. The efficiency and the accuracy of the algorithm were demonstrated for given external loadings. Numerical results were compared with those available in the literature.

  3. Observation of Nonlinear Compton Scattering

    SciTech Connect (OSTI)

    Kotseroglou, T.

    2003-12-19

    This experiment tests Quantum Electrodynamics in the strong field regime. Nonlinear Compton scattering has been observed during the interaction of a 46.6 GeV electron beam with a 10{sup 18} W/cm{sup 2} laser beam. The strength of the field achieved was measured by the parameter {eta} = e{var_epsilon}{sub rms}/{omega}mc = 0.6. Data were collected with infrared and green laser photons and circularly polarized laser light. The timing stabilization achieved between the picosecond laser and electron pulses has {sigma}{sub rms} = 2 ps. A strong signal of electrons that absorbed up to 4 infrared photons (or up to 3 green photons) at the same point in space and time, while emitting a single gamma ray, was observed. The energy spectra of the scattered electrons and the nonlinear dependence of the electron yield on the field strength agreed with the simulation over 3 orders of magnitude. The detector could not resolve the nonlinear Compton scattering from the multiple single Compton scattering which produced rates of scattered electrons of the same order of magnitude. Nevertheless, a simulation has studied this difference and concluded that the scattered electron rates observed could not be accounted for only by multiple ordinary Compton scattering; nonlinear Compton scattering processes are dominant for n {ge} 3.

  4. Non-Linear Seismic Soil Structure Interaction (SSI) Method for...

    Office of Environmental Management (EM)

    Non-Linear Seismic Soil Structure Interaction (SSI) Method for Developing Non-Linear Seismic SSI Analysis Techniques Non-Linear Seismic Soil Structure Interaction (SSI) Method for ...

  5. Non-linear Seismic Soil Structure Interaction Method for Developing...

    Office of Environmental Management (EM)

    Non-Linearity in Seismic SSI Analysis Commercial Software Elements Commercial Software Non-Linear Constitutive Models Non-Linear Seismic SSI Damping ...

  6. Protective laser beam viewing device

    DOE Patents [OSTI]

    Neil, George R.; Jordan, Kevin Carl

    2012-12-18

    A protective laser beam viewing system or device including a camera selectively sensitive to laser light wavelengths and a viewing screen receiving images from the laser sensitive camera. According to a preferred embodiment of the invention, the camera is worn on the head of the user or incorporated into a goggle-type viewing display so that it is always aimed at the area of viewing interest to the user and the viewing screen is incorporated into a video display worn as goggles over the eyes of the user.

  7. Waveguide Structures for RF Undulators with Applications to FELs and Storage Rings

    SciTech Connect (OSTI)

    Yeddulla, M.; Geng, H.G.; Huang, Z.; Ma, Z.; Tantawi, S.G.; /SLAC

    2011-11-02

    RF undulators, suggested a long time ago, have the advantage of fast dynamic control of polarization, undulator strength and wavelength. However, RF undulators require very strong RF fields in order to produce radiation of the same order as conventional static devices. Very high power RF energy confined inside a waveguide or a cavity can provide the necessary RF fields to undulate the electron beam. However, the wall losses in the waveguide should be low enough to make it practically feasible as a CW or quasi CW undulator and, hence, competitive with static devices for applications to storage rings and FELs. Here we present various waveguide structures such as smooth walled and corrugated walled waveguides and various RF modes. We will show that there are some advantages in operating with higher order modes and also with hybrid modes in the corrugated guide. We will show that the RF power requirement for some of these modes will permit a quasi CW operation of the undulator, thus permitting its operation in a storage ring.

  8. Test particle simulation of direct laser acceleration in a density-modulated plasma waveguide

    SciTech Connect (OSTI)

    Lin, M.-W.; Jovanovic, I.

    2012-11-15

    Direct laser acceleration (DLA) of electrons by the use of the intense axial electric field of an ultrafast radially polarized laser pulse is a promising technique for future compact accelerators. Density-modulated plasma waveguides can be implemented for guiding the propagation of the laser pulse to extend the acceleration distance and for the quasi-phase-matching between the accelerated electrons and the laser pulse. A test particle model is developed to study the optimal axial density modulation structure of plasma waveguides for laser pulses to efficiently accelerate co-propagating electrons. A simple analytical approach is also presented, which can be used to estimate the energy gain in DLA. The analytical model is validated by the test particle simulation. The effect of injection phase and acceleration of electrons injected at various radial positions are studied. The results indicate that a positively chirped density modulation of the waveguide structure is required to accelerate electron with low initial energies, and can be effectively optimized. A wider tolerance on the injection phase and radial distance from the waveguide axis exists for electrons injected with a higher initial energy.

  9. False color viewing device

    DOE Patents [OSTI]

    Kronberg, J.W.

    1992-10-20

    A viewing device for observing objects in near-infrared false-color comprising a pair of goggles with one or more filters in the apertures, and pads that engage the face for blocking stray light from the sides so that all light reaching the user's eyes come through the filters. The filters attenuate most visible light and pass near-infrared (having wavelengths longer than approximately 700 nm) and a small amount of blue-green and blue-violet (having wavelengths in the 500 to 520 nm and shorter than 435 nm, respectively). The goggles are useful for looking at vegetation to identify different species and for determining the health of the vegetation, and to detect some forms of camouflage. 7 figs.

  10. False color viewing device

    DOE Patents [OSTI]

    Kronberg, J.W.

    1991-05-08

    This invention consists of a viewing device for observing objects in near-infrared false-color comprising a pair of goggles with one or more filters in the apertures, and pads that engage the face for blocking stray light from the sides so that all light reaching, the user`s eyes come through the filters. The filters attenuate most visible light and pass near-infrared (having wavelengths longer than approximately 700 nm) and a small amount of blue-green and blue-violet (having wavelengths in the 500 to 520 nm and shorter than 435 nm, respectively). The goggles are useful for looking at vegetation to identify different species and for determining the health of the vegetation, and to detect some forms of camouflage.

  11. False color viewing device

    DOE Patents [OSTI]

    Kronberg, James W.

    1992-01-01

    A viewing device for observing objects in near-infrared false-color comprising a pair of goggles with one or more filters in the apertures, and pads that engage the face for blocking stray light from the sides so that all light reaching the user's eyes come through the filters. The filters attenuate most visible light and pass near-infrared (having wavelengths longer than approximately 700 nm) and a small amount of blue-green and blue-violet (having wavelengths in the 500 to 520 nm and shorter than 435 nm, respectively). The goggles are useful for looking at vegetation to identify different species and for determining the health of the vegetation, and to detect some forms of camouflage.

  12. The view from Kiev

    SciTech Connect (OSTI)

    Kiselyov, S.

    1993-11-01

    This article reports the observations of correspondents for the Bulletin (two Russian journalists, one based in Moscow, the other in Kiev) who investigated the status of the Soviet Union's Black Sea Fleet and Ukraine's status as a non-nuclear-weapons state. After two years of wrangling and two earlier failed settlements, Russian President Boris Yeltsin met with Ukrainian President Leonid Kravchuk at Massandra in Crimea. On September 3, the leaders announced that Russia would buy out Ukraine's interest in the fleet and lease the port at Sevastopol. The Massandra summit was also supposed to settle Ukraine's status as a non-nuclear-weapons state. Described here are the Kiev-based correspondent's views on the Massandra summit (and its major topics), which was to have been called off by the Russian foreign ministry when Ukrainian Prime Minister Leonid Kuchma resigned.

  13. Mountain View Grand | Open Energy Information

    Open Energy Info (EERE)

    Mountain View Grand Jump to: navigation, search Name Mountain View Grand Facility Mountain View Grand Sector Wind energy Facility Type Small Scale Wind Facility Status In Service...

  14. Nanowires and nanoribbons as subwavelength optical waveguides and their use as components in photonic circuits and devices

    DOE Patents [OSTI]

    Yang, Peidong; Law, Matt; Sirbuly, Donald J.; Johnson, Justin C.; Saykally, Richard; Fan, Rong; Tao, Andrea

    2012-10-02

    Nanoribbons and nanowires having diameters less than the wavelength of light are used in the formation and operation of optical circuits and devices. Such nanostructures function as subwavelength optical waveguides which form a fundamental building block for optical integration. The extraordinary length, flexibility and strength of these structures enable their manipulation on surfaces, including the precise positioning and optical linking of nanoribbon/wire waveguides and other nanoribbon/wire elements to form optical networks and devices. In addition, such structures provide for waveguiding in liquids, enabling them to further be used in other applications such as optical probes and sensors.

  15. Waveguide CO{sub 2} laser with a quasi-homogeneous distribution of the output radiation intensity

    SciTech Connect (OSTI)

    Vlasenko, S A; Gurin, O V; Degtyarev, A V; Maslov, Vyacheslav A; Svich, V A; Topkov, A N

    2013-05-31

    An experimental sample of a waveguide CO{sub 2} laser with a quasi-uniform profile of the output radiation intensity is designed on the basis of a waveguide quasi-optical cavity of a new type comprising the generic confocal cavity with a nonuniform mirror and the hollow waveguide with the dimensions satisfying the conditions for self-imaging the quasi-uniform field. The surface of the mirror has the discrete large-scale absorbing nonuniformities. Results of theoretical and experimental investigations of spatial-energy characteristics of the laser in using uniform or amplitude-stepped reflecting mirrors are presented. (lasers)

  16. Condition assessment of nonlinear processes

    DOE Patents [OSTI]

    Hively, Lee M.; Gailey, Paul C.; Protopopescu, Vladimir A.

    2002-01-01

    There is presented a reliable technique for measuring condition change in nonlinear data such as brain waves. The nonlinear data is filtered and discretized into windowed data sets. The system dynamics within each data set is represented by a sequence of connected phase-space points, and for each data set a distribution function is derived. New metrics are introduced that evaluate the distance between distribution functions. The metrics are properly renormalized to provide robust and sensitive relative measures of condition change. As an example, these measures can be used on EEG data, to provide timely discrimination between normal, preseizure, seizure, and post-seizure states in epileptic patients. Apparatus utilizing hardware or software to perform the method and provide an indicative output is also disclosed.

  17. Optic for an endoscope/borescope having high resolution and narrow field of view

    DOE Patents [OSTI]

    Stone, Gary F.; Trebes, James E.

    2003-10-28

    An optic having optimized high spatial resolution, minimal nonlinear magnification distortion while at the same time having a limited chromatic focal shift or chromatic aberrations. The optic located at the distal end of an endoscopic inspection tool permits a high resolution, narrow field of view image for medical diagnostic applications, compared to conventional optics for endoscopic instruments which provide a wide field of view, low resolution image. The image coverage is over a narrow (<20 degrees) field of view with very low optical distortion (<5% pin cushion or barrel distortion. The optic is also optimized for best color correction as well as to aid medical diagnostics.

  18. Nonlinear interaction of plane elastic waves

    SciTech Connect (OSTI)

    Korneev, V.A.; Nihei, K.T.; Myer, L.R.

    1998-06-01

    The paper presents basic first order results of nonlinear elastic theory by Murnaghan for elastic wave propagation in isotropic solids. The authors especially address the problem of resonant scattering of two collimated beams and present analytical solutions for amplitudes of all possible types of resonant interactions for elastic plane waves. For estimation of nonlinear scattered waves they use measured elastic parameters for sandstone. The most profound nonlinear effect is expected for interactions of two SH waves generating compressional P wave at sum frequency. Estimations show that nonlinear phenomena is likely to be observed in seismic data. Basic equations of nonlinear five-constant theory by Murnaghan are also presented.

  19. Fermilab | Tritium at Fermilab | Ferry Creek Aerial View

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

    Ferry Creek Aerial View Ferry Creek Aerial View

  20. Fermilab | Tritium at Fermilab | Kress Creek Aerial View

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

    Kress Creek Aerial View Kress Creek Aerial View

  1. Nonlinear dielectric thin films for active and electrically tunable microwave devices

    SciTech Connect (OSTI)

    Findikoglu, A.T.; Jia, Q.X.; Reagor, D.W.; Wu, X.D.

    1996-11-01

    The authors have prepared electrically tunable and active microwave devices incorporating (superconducting YBa{sub 2}Cu{sub 3}O{sub 7{minus}x})/(nonlinear dielectric SrTiO{sub 3}) or (normal metal Au)/(nonlinear dielectric Sr{sub 0.5}Ba{sub 0.5}TiO{sub 3}) bilayers. The dielectric layer thickness for these samples varied between 0.5 {micro}m and 2 {micro}m. The top electrode layer for each sample was patterned into a coplanar waveguide device structure. The authors have configures these devices as voltage-tunable resonators, voltage-tunable phase shifters, voltage-tunable mixers, and voltage-tunable filters. Under dc voltage bias, these prototype devices have exhibited up to 30% resonant frequency modulation, about 1{degree}/mm-GHz phase shift, more than 40 dB change in mixed microwave power, and fine-tunable symmetric filter profile with less than 2% bandwidth and more than 15% adaptive range.

  2. Direct-bandgap electroluminescence from a horizontal Ge p-i-n ridge waveguide on Si(001) substrate

    SciTech Connect (OSTI)

    Liu, Zhi; Li, Yaming; He, Chao; Li, Chuanbo; Xue, Chunlai; Zuo, Yuhua; Cheng, Buwen Wang, Qiming

    2014-05-12

    Horizontal injection Ge p-i-n ridge waveguide light emitting diodes (LEDs) were fabricated on n{sup ?}-Si(001) substrates by ultrahigh vacuum chemical vapor deposition. The direct-bandgap electroluminescence (EL) of Ge waveguide LEDs under a continuous/pulse electrical pump was studied. The heating effect from a continuous electrical pump was found to significantly enhance the emission of devices. The top surface EL intensity of the Ge waveguide LEDs significantly depended on the position. Most direct-bandgap radiative recombination of Ge p-i-n waveguide LEDs occurred near the N{sup +} region of the junction. This interesting phenomenon could be explained by the carrier distribution in the junction and the pseudo-direct bandgap of Ge.

  3. Nonlinear

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

    R. Gatto Universit di Roma "Tor Vergata", 00133 Rome, Italy P. W. Terry and D. A. Baver University of Wisconsin-Madison, Madison, Wisconsin 53706 Received 25 July 2005; ...

  4. Nonlinear

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

    A review of the literature suggests there is no universal process, but multiple ... Heavy ion beam probe measurements of both density and potential in the Texas Experimental ...

  5. Nonlinear

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

    ... to zonal modes on the damped eigenmode branch. 23 Other channels, e.g., en- ergy ... Controlled Fusion 47, B195 2005. 9 D. R. Baker and M. N. Rosenbluth, Phys. Plasmas 5, ...

  6. Highland View school | Y-12 National Security Complex

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

    Highland View school Highland View school Aerial showing Highland View school and surrounding homes

  7. Radiation View Factor With Shadowing

    Energy Science and Technology Software Center (OSTI)

    1992-02-24

    FACET calculates the radiation geometric view factor (alternatively called shape factor, angle factor, or configuration factor) between surfaces for axisymmetric, two-dimensional planar and three-dimensional geometries with interposed third surface obstructions. FACET was developed to calculate view factors as input data to finite element heat transfer analysis codes.

  8. Beams on nonlinear elastic foundation

    SciTech Connect (OSTI)

    Lukkassen, Dag; Meidell, Annette

    2014-12-10

    In order to determination vertical deflections and rail bending moments the Winkler model (1867) is often used. This linear model neglects several conditions. For example, by using experimental results, it has been observed that there is a substantial increase in the maximum rail deflection and rail bending moment when considering the nonlinearity of the track support system. A deeper mathematical analysis of the models is necessary in order to obtain better methods for more accurate numerical solutions in the determination of deflections and rail bending moments. This paper is intended to be a small step in this direction.

  9. Nonlinear structural crack growth monitoring

    DOE Patents [OSTI]

    Welch, Donald E.; Hively, Lee M.; Holdaway, Ray F.

    2002-01-01

    A method and apparatus are provided for the detection, through nonlinear manipulation of data, of an indicator of imminent failure due to crack growth in structural elements. The method is a process of determining energy consumption due to crack growth and correlating the energy consumption with physical phenomena indicative of a failure event. The apparatus includes sensors for sensing physical data factors, processors or the like for computing a relationship between the physical data factors and phenomena indicative of the failure event, and apparatus for providing notification of the characteristics and extent of such phenomena.

  10. High-Gradient Tests of the Single-Cell SC Cavity with a Feedback Waveguide

    SciTech Connect (OSTI)

    Yakovlev, V.; Solyak, N.; Wu, G.; Ge, M.; Gonin, I.; Khabiboulline, T.; Ozelis, J.; Rowe, A. [Fermilab, Batavia, IL 60510 (United States); Avrakhov, P.; Kanareykin, A. [Euclid TechLabs, LLC, Solon, Ohio 44139 (United States); Rathke, J. [AES, Medford, NY 11763 (United States)

    2010-11-04

    Use of a superconducting (SC) traveling-wave accelerating (STWA) structure with a small phase advance per cell, rather than a standing-wave structure, may provide a significant increase in the accelerating gradient in the ILC linac [1]. For the same surface electric and magnetic fields, the STWA achieves an accelerating gradient 1.2 larger than TESLA-like standing-wave cavities. In addition, the STWA allows longer acceleration cavities, reducing the number of gaps between them. However, the STWA structure requires a SC feedback waveguide to return the few hundreds of MW of circulating RF power from the structure output to the structure input. A test single-cell cavity with feedback was designed and manufactured to demonstrate the possibility of proper processing to achieve a high accelerating gradient. The first results of high-gradient tests of a prototype 1.3 GHz single-cell cavity with feedback waveguide will be presented.

  11. Metallic nanoparticles grown in the core of femtosecond laser micromachined waveguides

    SciTech Connect (OSTI)

    Almeida, J. M. P.; Ferreira, P. H. D.; Mendona, C. R.; Manzani, D.; Napoli, M.; Ribeiro, S. J. L.

    2014-05-21

    3D-waveguides containing silver nanoparticles have been fabricated in tungsten leadpyrophosphate glass by femtosecond laser micromachining. Nucleation and growth of nanoparticles occur in a single step process when high repetition rate laser (MHz) is employed, while an additional annealing is required for the irradiation using kHz laser system. The presence of nanoparticles locally changes the refractive index, and, therefore, the elliptical structures produced by direct laser writing were able to guide light. By increasing the pulse energy applied during the micromachining, the waveguide size increased from 2 to 30??m, while their propagation loss decrease from 1.4 to 0.5?dB/mm at 632.8?nm.

  12. Lightwave Circuits in Lithium Niobate through Hybrid Waveguides with Silicon Photonics

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

    Weigel, Peter O.; Savanier, Marc; DeRose, Christopher T.; Pomerene, Andrew T.; Starbuck, Andrew L.; Lentine, Anthony L.; Stenger, Vincent; Mookherjea, Shayan

    2016-03-01

    Here we demonstrate a photonic waveguide technology based on a two-material core, in which light is controllably and repeatedly transferred back and forth between sub-micron thickness crystalline layers of Si and LN bonded to one another, where the former is patterned and the latter is not. In this way, the foundry-based wafer-scale fabrication technology for silicon photonics can be leveraged to form lithium-niobate based integrated optical devices. Using two different guided modes and an adiabatic mode transition between them, we demonstrate a set of building blocks such as waveguides, bends, and couplers which can be used to route light underneathmore » an unpatterned slab of LN, as well as outside the LN-bonded region, thus enabling complex and compact lightwave circuits in LN alongside Si photonics with fabrication ease and low cost.« less

  13. Energy exchange between electromagnetic waves on the director diffraction grating in planar waveguide with nematic layer

    SciTech Connect (OSTI)

    Ledney, M. F. Tarnavskyy, A. S.

    2013-09-15

    The energy exchange between two coupled TE modes on the diffraction grating of the director in a planar waveguide containing a nematic liquid crystal layer is calculated. The diffraction grating is induced by an external electric field in the nematic layer with periodic anchoring energy at the waveguide surface. The intensity of the signal mode at the output of the nematic layer is calculated as a function of the amplitude and period of the anchoring-energy modulation, the nematic layer sizes, and the electric-field strength. The cases of modes with the same and opposite directions are considered. Analytical expressions for the maximum intensities of the signal mode are derived. In both cases the maximum intensity of the signal mode increases with an increase in the electric-field strength.

  14. Toward photostable multiplex analyte detection on a single mode planar optical waveguide

    SciTech Connect (OSTI)

    Mukundan, Harshini; Xei, Hongshi; Anderson, Aaron S; Grace, Wynne K; Martinez, Jennifer S; Swanson, Basil

    2009-01-01

    We have developed a waveguide-based optical biosensor for the sensitive and specific detection of biomarkers associated with disease. Our technology combines the superior optical properties of single-mode planar waveguides, the robust nature of functionalized self-assembled monolayer sensing films and the specificity of fluorescence sandwich immunoassays to detect biomarkers in complex biological samples such as serum, urine and sputum. We have previously reported the adaptation of our technology to the detection of biomarkers associated with breast cancer and anthrax. However, these approaches primarily used phospholipid bilayers as the functional film and organic dyes (ex: AlexaFluors) as the fluorescence reporter. Organic dyes are easily photodegraded and are not amenable to multiplexing because of their narrow Stokes' shift. Here we have developed strategies for conjugation of the detector antibodies with quantum dots for use in a multiplex detection platform. We have previously evaluated dihydroxylipoic acid quantum dots for the detection of a breast cancer biomarker. In this manuscript, we investigate the detection of the Bacillus anthracis protective antigen using antibodies conjugated with polymer-coated quantum dots. Kinetics of binding on the waveguide-based biosensor is reported. We compare the sensitivity of quantum dot labeled antibodies to those labeled with AlexaFluor and demonstrate the photostability of the former in our assay platform. In addition, we compare sulfydryl labeling of the antibody in the hinge region to that of nonspecific amine labeling. This is but the first step in developing a multiplex assay for such biomarkers on our waveguide platform.

  15. Low-loss LIGA-micromachined conductor-backed coplanar waveguide.

    SciTech Connect (OSTI)

    Forman, Michael A.

    2004-12-01

    A mesoscale low-loss LIGA-micromachined conductor-backed coplanar waveguide is presented. The 517 {micro}m lines are the tallest uniplanar LIGA-fabricated microwave transmission lines to date, as well as the first to be constructed of copper rather than nickel. The conductor-backed micromachined CPW on quartz achieves a measured attenuation of 0.064 dB/cm at 15.5 GHz.

  16. Detonator comprising a nonlinear transmission line

    DOE Patents [OSTI]

    Elizondo-Decanini, Juan M

    2014-12-30

    Detonators are described herein. In a general embodiment, the detonator includes a nonlinear transmission line that has a variable capacitance. Capacitance of the nonlinear transmission line is a function of voltage on the nonlinear transmission line. The nonlinear transmission line receives a voltage pulse from a voltage source and compresses the voltage pulse to generate a trigger signal. Compressing the voltage pulse includes increasing amplitude of the voltage pulse and decreasing length of the voltage pulse in time. An igniter receives the trigger signal and detonates an explosive responsive to receipt of the trigger signal.

  17. Correlation between piezoresponse nonlinearity and hysteresis...

    Office of Scientific and Technical Information (OSTI)

    hysteresis in ferroelectric crystals at nanoscale This content will become publicly ... hysteresis in ferroelectric crystals at nanoscale Here, the nonlinear response of a ...

  18. Sandia National Laboratories: Careers: Special Programs: Nonlinear...

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

    Nonlinear Mechanics and Dynamics Research Institute FEA modeling simulation A test specimen for measuring dissipation across a lap joint under different loading environments (top), ...

  19. Development of Nonlinear SSI Time Domain Methodology

    Broader source: Energy.gov [DOE]

    Development of Nonlinear SSI Time Domain Methodology Justin Coleman, P.E. Nuclear Science and Technology Idaho National Laboratory October 22, 2014

  20. Control of waveguide properties by tuning femtosecond laser induced compositional changes

    SciTech Connect (OSTI)

    Hoyo, Jess; Fernandez, Toney Teddy del; Siegel, Jan; Solis, Javier; Vazquez, Rebeca Martinez; Osellame, Roberto; Sotillo, Beln; Fernndez, Paloma

    2014-09-29

    Local compositional changes induced by high repetition rate fs-laser irradiation can be used to produce high performance optical waveguides in phosphate-based glasses. The waveguide refractive index contrast is determined by the local concentration of La, which can be changed by the action of the writing laser pulses. In this work, we have investigated the degree of control that can be exerted using this waveguide writing mechanism over the cross-section of the guiding region, and the local refractive index and compositional changes induced. These variables can be smoothly controlled via processing parameters using the slit shaping technique with moderate Numerical Aperture (NA 0.68) writing optics. The combined use of X-ray microanalysis and near field refractive index profilometry evidences a neat linear correlation between local La content and refractive index increase over a broad ?n interval (>3??10{sup ?2}). This result further confirms the feasibility of generating efficient, integrated optics elements via spatially selective modification of the glass composition.

  1. Nonlinearity in modal and vibration testing.

    SciTech Connect (OSTI)

    Hunter, N. F.

    2003-01-01

    This set of slides describes some aspects of nonlinear Vibration analysis thru use of analytical fromulas and Examples from real or simulated test systems . The Systems are drawn from a set of examples based on Years of vibration testing experience . Both traditional and new methods are used to describe nonlinear vibration.

  2. Nonlinear lower hybrid modeling in tokamak plasmas

    SciTech Connect (OSTI)

    Napoli, F.; Schettini, G.; Castaldo, C.; Cesario, R.

    2014-02-12

    We present here new results concerning the nonlinear mechanism underlying the observed spectral broadening produced by parametric instabilities occurring at the edge of tokamak plasmas in present day LHCD (lower hybrid current drive) experiments. Low frequency (LF) ion-sound evanescent modes (quasi-modes) are the main parametric decay channel which drives a nonlinear mode coupling of lower hybrid (LH) waves. The spectrum of the LF fluctuations is calculated here considering the beating of the launched LH wave at the radiofrequency (RF) operating line frequency (pump wave) with the noisy background of the RF power generator. This spectrum is calculated in the frame of the kinetic theory, following a perturbative approach. Numerical solutions of the nonlinear LH wave equation show the evolution of the nonlinear mode coupling in condition of a finite depletion of the pump power. The role of the presence of heavy ions in a Deuterium plasma in mitigating the nonlinear effects is analyzed.

  3. Nonlinear Krylov acceleration of reacting flow codes

    SciTech Connect (OSTI)

    Kumar, S.; Rawat, R.; Smith, P.; Pernice, M.

    1996-12-31

    We are working on computational simulations of three-dimensional reactive flows in applications encompassing a broad range of chemical engineering problems. Examples of such processes are coal (pulverized and fluidized bed) and gas combustion, petroleum processing (cracking), and metallurgical operations such as smelting. These simulations involve an interplay of various physical and chemical factors such as fluid dynamics with turbulence, convective and radiative heat transfer, multiphase effects such as fluid-particle and particle-particle interactions, and chemical reaction. The governing equations resulting from modeling these processes are highly nonlinear and strongly coupled, thereby rendering their solution by traditional iterative methods (such as nonlinear line Gauss-Seidel methods) very difficult and sometimes impossible. Hence we are exploring the use of nonlinear Krylov techniques (such as CMRES and Bi-CGSTAB) to accelerate and stabilize the existing solver. This strategy allows us to take advantage of the problem-definition capabilities of the existing solver. The overall approach amounts to using the SIMPLE (Semi-Implicit Method for Pressure-Linked Equations) method and its variants as nonlinear preconditioners for the nonlinear Krylov method. We have also adapted a backtracking approach for inexact Newton methods to damp the Newton step in the nonlinear Krylov method. This will be a report on work in progress. Preliminary results with nonlinear GMRES have been very encouraging: in many cases the number of line Gauss-Seidel sweeps has been reduced by about a factor of 5, and increased robustness of the underlying solver has also been observed.

  4. Nonlinear frequency shift of electrostatic waves in general collisionl...

    Office of Scientific and Technical Information (OSTI)

    Nonlinear frequency shift of electrostatic waves in general collisionless plasma: Unifying theory of fluid and kinetic nonlinearities Citation Details In-Document Search This...

  5. Frequency dispersion of nonlinear response of thin superconducting...

    Office of Scientific and Technical Information (OSTI)

    Frequency dispersion of nonlinear response of thin superconducting films in the Berezinskii-Kosterlitz-Thouless state Prev Next Title: Frequency dispersion of nonlinear ...

  6. Nonlinear Development of Shocklike Structure in the Solar Wind...

    Office of Scientific and Technical Information (OSTI)

    Nonlinear Development of Shocklike Structure in the Solar Wind Citation Details In-Document Search Title: Nonlinear Development of Shocklike Structure in the Solar Wind We report ...

  7. Online optimization of storage ring nonlinear beam dynamics ...

    Office of Scientific and Technical Information (OSTI)

    Online optimization of storage ring nonlinear beam dynamics Citation Details In-Document Search Title: Online optimization of storage ring nonlinear beam dynamics Authors: Huang,...

  8. Online optimization of storage ring nonlinear beam dynamics ...

    Office of Scientific and Technical Information (OSTI)

    Online optimization of storage ring nonlinear beam dynamics Citation Details In-Document Search Title: Online optimization of storage ring nonlinear beam dynamics You are...

  9. Precision Determination Of The Nonlinear Matter Power Spectrum...

    Office of Scientific and Technical Information (OSTI)

    Precision Determination Of The Nonlinear Matter Power Spectrum Citation Details In-Document Search Title: Precision Determination Of The Nonlinear Matter Power Spectrum You are...

  10. Solving a Class of Nonlinear Eigenvalue Problems by Newton's...

    Office of Scientific and Technical Information (OSTI)

    We examine the possibility of using the standard Newton's method for solving a class of ... NONLINEAR PROBLEMS nonlinear eigenvalue problem, Newton's method Word Cloud More Like ...

  11. Nonlinear modelling of polymer electrolyte membrane fuel cell stack using nonlinear cancellation technique

    SciTech Connect (OSTI)

    Barus, R. P. P.; Tjokronegoro, H. A.; Leksono, E.; Ismunandar

    2014-09-25

    Fuel cells are promising new energy conversion devices that are friendly to the environment. A set of control systems are required in order to operate a fuel cell based power plant system optimally. For the purpose of control system design, an accurate fuel cell stack model in describing the dynamics of the real system is needed. Currently, linear model are widely used for fuel cell stack control purposes, but it has limitations in narrow operation range. While nonlinear models lead to nonlinear control implemnetation whos more complex and hard computing. In this research, nonlinear cancellation technique will be used to transform a nonlinear model into a linear form while maintaining the nonlinear characteristics. The transformation is done by replacing the input of the original model by a certain virtual input that has nonlinear relationship with the original input. Then the equality of the two models is tested by running a series of simulation. Input variation of H2, O2 and H2O as well as disturbance input I (current load) are studied by simulation. The error of comparison between the proposed model and the original nonlinear model are less than 1 %. Thus we can conclude that nonlinear cancellation technique can be used to represent fuel cell nonlinear model in a simple linear form while maintaining the nonlinear characteristics and therefore retain the wide operation range.

  12. Minimizing radiation damage in nonlinear optical crystals

    DOE Patents [OSTI]

    Cooke, D. Wayne; Bennett, Bryan L.; Cockroft, Nigel J.

    1998-01-01

    Methods are disclosed for minimizing laser induced damage to nonlinear crystals, such as KTP crystals, involving various means for electrically grounding the crystals in order to diffuse electrical discharges within the crystals caused by the incident laser beam. In certain embodiments, electrically conductive material is deposited onto or into surfaces of the nonlinear crystals and the electrically conductive surfaces are connected to an electrical ground. To minimize electrical discharges on crystal surfaces that are not covered by the grounded electrically conductive material, a vacuum may be created around the nonlinear crystal.

  13. Minimizing radiation damage in nonlinear optical crystals

    DOE Patents [OSTI]

    Cooke, D.W.; Bennett, B.L.; Cockroft, N.J.

    1998-09-08

    Methods are disclosed for minimizing laser induced damage to nonlinear crystals, such as KTP crystals, involving various means for electrically grounding the crystals in order to diffuse electrical discharges within the crystals caused by the incident laser beam. In certain embodiments, electrically conductive material is deposited onto or into surfaces of the nonlinear crystals and the electrically conductive surfaces are connected to an electrical ground. To minimize electrical discharges on crystal surfaces that are not covered by the grounded electrically conductive material, a vacuum may be created around the nonlinear crystal. 5 figs.

  14. Resonant absorption in semiconductor nanowires and nanowire arrays: Relating leaky waveguide modes to Bloch photonic crystal modes

    SciTech Connect (OSTI)

    Fountaine, Katherine T.; Whitney, William S.; Atwater, Harry A.

    2014-10-21

    We present a unified framework for resonant absorption in periodic arrays of high index semiconductor nanowires that combines a leaky waveguide theory perspective and that of photonic crystals supporting Bloch modes, as array density transitions from sparse to dense. Full dispersion relations are calculated for each mode at varying illumination angles using the eigenvalue equation for leaky waveguide modes of an infinite dielectric cylinder. The dispersion relations along with symmetry arguments explain the selectivity of mode excitation and spectral red-shifting of absorption for illumination parallel to the nanowire axis in comparison to perpendicular illumination. Analysis of photonic crystal band dispersion for varying array density illustrates that the modes responsible for resonant nanowire absorption emerge from the leaky waveguide modes.

  15. Wide field of view telescope

    DOE Patents [OSTI]

    Ackermann, Mark R.; McGraw, John T.; Zimmer, Peter C.

    2008-01-15

    A wide field of view telescope having two concave and two convex reflective surfaces, each with an aspheric surface contour, has a flat focal plane array. Each of the primary, secondary, tertiary, and quaternary reflective surfaces are rotationally symmetric about the optical axis. The combination of the reflective surfaces results in a wide field of view in the range of approximately 3.8.degree. to approximately 6.5.degree.. The length of the telescope along the optical axis is approximately equal to or less than the diameter of the largest of the reflective surfaces.

  16. Non-Linear Seismic Soil Structure Interaction (SSI) Method for Developing Non-Linear Seismic SSI Analysis Techniques

    Broader source: Energy.gov [DOE]

    Non-Linear Seismic Soil Structure Interaction (SSI) Method for Developing Non-Linear Seismic SSI Analysis Techniques Justin Coleman, P.E. October 25th, 2011

  17. Stochastic features of multipactor in coaxial waveguides for travelling and standing waves

    SciTech Connect (OSTI)

    Romanov, Gennady; /Fermilab

    2011-02-01

    CST Particle Studio combines electromagnetic field simulation, multi-particle tracking, adequate post-processing and advanced probabilistic emission model, which is the most important new capability in multipactor simulation. The emission model includes in simulation the stochastic properties of emission and adds primary electron elastic and inelastic reflection from the surfaces. The simulation of multipactor in coaxial waveguides have been performed to study the effects of the innovations on the multipactor threshold and the range over which multipactor can occur. The results compared with available previous experiments and simulations as well as the technique of MP simulation with CST PS are presented and discussed.

  18. Restricted thermalization for two interacting atoms in a multimode harmonic waveguide

    SciTech Connect (OSTI)

    Yurovsky, V. A.; Olshanii, M. [School of Chemistry, Tel Aviv University, IL-69978 Tel Aviv (Israel); Department of Physics, University of Massachusetts Boston, Boston, Massachusetts 02125 (United States)

    2010-04-15

    In this article, we study the thermalizability of a system consisting of two atoms in a circular, transversely harmonic waveguide in the multimode regime. While showing some signatures of quantum-chaotic behavior, the system fails to reach a thermal equilibrium in a relaxation from an initial state, even when the interaction between the atoms is infinitely strong. We relate this phenomenon to the previously addressed unattainability of a complete quantum chaos in the Seba billiard [P. Seba, Phys. Rev. Lett. 64, 1855 (1990)], and we conjecture the absence of a complete thermalization to be a generic property of integrable quantum systems perturbed by a nonintegrable but well-localized perturbation.

  19. Investigation of Propagation Characteristics of Twisted Hollow Waveguides for Particle Accelerator Applications

    SciTech Connect (OSTI)

    Wilson, Joshua L

    2008-09-01

    A new class of accelerating structures employing a uniformly twisted waveguide is investigated. Twisted waveguides of various cross-sectional geometries are considered and analyzed. It is shown that such a twisted waveguide can support waves that travel at a speed slower than the speed of light c. The slow-wave properties of twisted structures are of interest because these slow-wave electromagnetic fields can be used in applications such as electron traveling wave tubes and linear particle accelerators. Since there is no exact closed form solution for the electromagnetic fields within a twisted waveguide or cavity, several previously proposed approximate methods are examined, and more effcient approaches are developed. It is found that the existing perturbation theory methods yield adequate results for slowly twisted structures; however, our efforts here are geared toward analyzing rapidly twisted structures using modifed finite difference methods specially suited for twisted structures. Although the method can handle general twisted structures, three particular cross sections are selected as representative cases for careful analysis. First, a slowly twisted rectangular cavity is analyzed as a reference case. This is because its shape is simple and perturbation theory already gives a good approximate solution for such slow twists rates. Secondly, a symmetrically notched circular cross section is investigated, since its longitudinal cross section is comparable to the well known disk-loaded cavity (used in many practical accelerator designs, including SLAC). Finally, a "dumbbell" shaped cross section is analyzed because of its similarity to the well-known TESLA-type accelerating cavity, which is of great importance because of its wide acceptance as a superconducting cavity. To validate the results of the developed theory and our extensive simulations, the newly developed numerical models are compared to commercial codes. Also, several prototypes are developed

  20. Measuring Photochemical Kinetics in Submonolayer Films by Transient ATR Spectroscopy on a Multimode Planar Waveguide

    SciTech Connect (OSTI)

    Simon, Anne M.; Marucci, Nicole E.; Saavedra, S. Scott

    2011-07-15

    Understanding the kinetics of reactions in molecular thin films can aid in the molecular engineering of organic photovoltaics and biosensors. Using two analytical methods, transient absorbance spectroscopy (TAS) and attenuated total reflectance (ATR), in a relatively simple arrangement when compared with previous TAS/ATR instruments to interrogate molecular structure and photochemistry at interfaces. The multimode planar waveguide geometry provides a significant path length enhancement relative to a conventional transmission geometry, making it feasible to perform measurements on low-surface-coverage films. This work demonstrates that TAS/ATR can be used to probe structure and photochemical kinetics in molecular films at extremely low surface coverages.

  1. Spin-wave excitation and propagation in microstructured waveguides of yttrium iron garnet/Pt bilayers

    SciTech Connect (OSTI)

    Pirro, P.; Chumak, A. V.; Lägel, B.; Leven, B.; Hillebrands, B.; Brächer, T.; Graduate School Materials Science in Mainz, Gottlieb-Daimler-Strasse 47, D-67663 Kaiserslautern ; Dubs, C.; Surzhenko, O.; Görnert, P.

    2014-01-06

    We present an experimental study of spin-wave excitation and propagation in microstructured waveguides consisting of a 100 nm thick yttrium iron garnet/platinum (Pt) bilayer. The life time of the spin waves is found to be more than an order of magnitude higher than in comparably sized metallic structures, despite the fact that the Pt capping enhances the Gilbert damping. Utilizing microfocus Brillouin light scattering spectroscopy, we reveal the spin-wave mode structure for different excitation frequencies. An exponential spin-wave amplitude decay length of 31 μm is observed which is a significant step towards low damping, insulator based micro-magnonics.

  2. Soliton production with nonlinear homogeneous lines

    SciTech Connect (OSTI)

    Elizondo-Decanini, Juan M.; Coleman, Phillip D.; Moorman, Matthew W.; Petney, Sharon Joy Victor; Dudley, Evan C.; Youngman, Kevin; Penner, Tim Dwight; Fang, Lu; Myers, Katherine M.

    2015-11-24

    Low- and high-voltage Soliton waves were produced and used to demonstrate collision and compression using diode-based nonlinear transmission lines. Experiments demonstrate soliton addition and compression using homogeneous nonlinear lines. We built the nonlinear lines using commercially available diodes. These diodes are chosen after their capacitance versus voltage dependence is used in a model and the line design characteristics are calculated and simulated. Nonlinear ceramic capacitors are then used to demonstrate high-voltage pulse amplification and compression. The line is designed such that a simple capacitor discharge, input signal, develops soliton trains in as few as 12 stages. We also demonstrated output voltages in excess of 40 kV using Y5V-based commercial capacitors. The results show some key features that determine efficient production of trains of solitons in the kilovolt range.

  3. NOX: An Object-Oriented Nonlinear Solver

    Energy Science and Technology Software Center (OSTI)

    2002-11-15

    NOX is a C++ object-oriented library for the solving nonlinear equations. It can be used with an linear algebra package and includes interfaces to Epetra and PETSc.

  4. Electromagnetic nonlinear gyrokinetics with polarization drift

    SciTech Connect (OSTI)

    Duthoit, F.-X.; Hahm, T. S.; Wang, Lu

    2014-08-15

    A set of new nonlinear electromagnetic gyrokinetic Vlasov equation with polarization drift and gyrokinetic Maxwell equations is systematically derived by using the Lie-transform perturbation method in toroidal geometry. For the first time, we recover the drift-kinetic expression for parallel acceleration [R. M. Kulsrud, in Basic Plasma Physics, edited by A. A. Galeev and R. N. Sudan (North-Holland, Amsterdam, 1983)] from the nonlinear gyrokinetic equations, thereby bridging a gap between the two formulations. This formalism should be useful in addressing nonlinear ion Compton scattering of intermediate-mode-number toroidal Alfvén eigenmodes for which the polarization current nonlinearity [T. S. Hahm and L. Chen, Phys. Rev. Lett. 74, 266 (1995)] and the usual finite Larmor radius effects should compete.

  5. Soliton production with nonlinear homogeneous lines

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

    Elizondo-Decanini, Juan M.; Coleman, Phillip D.; Moorman, Matthew W.; Petney, Sharon Joy Victor; Dudley, Evan C.; Youngman, Kevin; Penner, Tim Dwight; Fang, Lu; Myers, Katherine M.

    2015-11-24

    Low- and high-voltage Soliton waves were produced and used to demonstrate collision and compression using diode-based nonlinear transmission lines. Experiments demonstrate soliton addition and compression using homogeneous nonlinear lines. We built the nonlinear lines using commercially available diodes. These diodes are chosen after their capacitance versus voltage dependence is used in a model and the line design characteristics are calculated and simulated. Nonlinear ceramic capacitors are then used to demonstrate high-voltage pulse amplification and compression. The line is designed such that a simple capacitor discharge, input signal, develops soliton trains in as few as 12 stages. We also demonstrated outputmore » voltages in excess of 40 kV using Y5V-based commercial capacitors. The results show some key features that determine efficient production of trains of solitons in the kilovolt range.« less

  6. Giant optical nonlinearity of plasmonic nanostructures

    SciTech Connect (OSTI)

    Melentiev, P N; Afanasev, A E; Balykin, V I

    2014-06-30

    The experimental studies of giant optical nonlinearity of single metal nanostructures are briefly reviewed. A new hybrid nanostructure – split-hole resonator (SHR) – is investigated. This structure is characterised by a record-high efficiency of third-harmonic generation and multiphoton luminescence (its nonlinearity exceeds that of a single nanohole by five orders of magnitude) and an unprecedently high sensitivity to light polarisation (extinction coefficient 4 × 10{sup 4}). (extreme light fields and their applications)

  7. NONLINEAR DYNAMICS OF MAGNETOHYDRODYNAMIC ROSSBY WAVES AND THE CYCLIC NATURE OF SOLAR MAGNETIC ACTIVITY

    SciTech Connect (OSTI)

    Raphaldini, Breno; Raupp, Carlos F. M. E-mail: carlos.raupp@iag.usp.br

    2015-01-20

    The solar dynamo is known to be associated with several periodicities, with the nearly 11/22 yr cycle being the most pronounced one. Even though these quasiperiodic variations of solar activity have been attributed to the underlying dynamo action in the Sun's interior, a fundamental theoretical description of these cycles is still elusive. Here, we present a new possible direction in understanding the Sun's cycles based on resonant nonlinear interactions among magnetohydrodynamic (MHD) Rossby waves. The WKB theory for dispersive waves is applied to magnetohydrodynamic shallow-water equations describing the dynamics of the solar tachocline, and the reduced dynamics of a resonant triad composed of MHD Rossby waves embedded in constant toroidal magnetic field is analyzed. In the conservative case, the wave amplitudes evolve periodically in time, with periods on the order of the dominant solar activity timescale (∼11 yr). In addition, the presence of linear forcings representative of either convection or instabilities of meridionally varying background states appears to be crucial in balancing dissipation and thus sustaining the periodic oscillations of wave amplitudes associated with resonant triad interactions. Examination of the linear theory of MHD Rossby waves embedded in a latitudinally varying mean flow demonstrates that MHD Rossby waves propagate toward the equator in a waveguide from –35° to 35° in latitude, showing a remarkable resemblance to the structure of the butterfly diagram of the solar activity. Therefore, we argue that resonant nonlinear magnetohydrodynamic Rossby wave interactions might significantly contribute to the observed cycles of magnetic solar activity.

  8. Theoretical and experimental investigations of asymmetric light transport in graded index photonic crystal waveguides

    SciTech Connect (OSTI)

    Giden, I. H. Yilmaz, D.; Turduev, M.; Kurt, H.; olak, E.; Ozbay, E.

    2014-01-20

    To provide asymmetric propagation of light, we propose a graded index photonic crystal (GRIN PC) based waveguide configuration that is formed by introducing line and point defects as well as intentional perturbations inside the structure. The designed system utilizes isotropic materials and is purely reciprocal, linear, and time-independent, since neither magneto-optical materials are used nor time-reversal symmetry is broken. The numerical results show that the proposed scheme based on the spatial-inversion symmetry breaking has different forward (with a peak value of 49.8%) and backward transmissions (4.11% at most) as well as relatively small round-trip transmission (at most 7.11%) in a large operational bandwidth of 52.6?nm. The signal contrast ratio of the designed configuration is above 0.80 in the telecom wavelengths of 1523.51576.1?nm. An experimental measurement is also conducted in the microwave regime: A strong asymmetric propagation characteristic is observed within the frequency interval of 12.8 GHz13.3?GHz. The numerical and experimental results confirm the asymmetric transmission behavior of the proposed GRIN PC waveguide.

  9. Views of the solar system

    SciTech Connect (OSTI)

    Hamilton, C.

    1995-02-01

    Views of the Solar System has been created as an educational tour of the solar system. It contains images and information about the Sun, planets, moons, asteroids and comets found within the solar system. The image processing for many of the images was done by the author. This tour uses hypertext to allow space travel by simply clicking on a desired planet. This causes information and images about the planet to appear on screen. While on a planet page, hyperlinks travel to pages about the moons and other relevant available resources. Unusual terms are linked to and defined in the Glossary page. Statistical information of the planets and satellites can be browsed through lists sorted by name, radius and distance. History of Space Exploration contains information about rocket history, early astronauts, space missions, spacecraft and detailed chronology tables of space exploration. The Table of Contents page has links to all of the various pages within Views Of the Solar System.

  10. For current viewing resistor loads

    DOE Patents [OSTI]

    Lyons, Gregory R.; Hass, Jay B.

    2011-04-19

    The invention comprises a terminal unit for a flat cable comprising a BNC-PCB connector having a pin for electrically contacting one or more conducting elements of a flat cable, and a current viewing resistor having an opening through which the pin extends and having a resistor face that abuts a connector face of the BNC-PCB connector, wherein the device is a terminal unit for the flat cable.