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

Journal Article · Mon Aug 15 04:00:00 EDT 2011 · Physical Review. A

DOI:https://doi.org/10.1103/PHYSREVA.84.021801· OSTI ID:22068471

Xi, Wang; Kai, Wang; Welch, George R; Sokolov, Alexei V ^[1]

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1. Department of Physics and Institute of Quantum Science and Engineering, Texas A and M University, College Station, Texas 77843-4242 (United States)

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

• OSTI ID: 22068471
• Journal Information: Physical Review. A, Journal Name: Physical Review. A Journal Issue: 2 Vol. 84; ISSN 1050-2947; ISSN PLRAAN
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
INTERFERENCE
LASERS
OSCILLATIONS
PULSES
RAMAN EFFECT
RAMAN SPECTRA