Hybrid femtosecond/picosecond (fs/ps) vibrational coherent anti‐Stokes Raman scattering
was demonstrated for high‐speed, in‐situ measurements of CH4/N2 mole fractions in binary
gas mixtures with temporal nonresonant suppression. A single broadband, 100‐fs laser
source was used to simultaneously excite CH4 and N2 vibrational Raman transitions,
characterized by a spectral separation of~ 584 cm− 1, followed by frequency‐domain
detection with a time‐delayed ps probe pulse. In this manner, the temporal evolution of the …

We demonstrate hybrid femtosecond/picosecond (fs/ps) coherent anti-Stokes Raman
scattering for high-speed thermometry in unsteady high-temperature flames, including
successful comparisons with a time-and frequency-resolved theoretical model. After
excitation of the N_2 vibrational manifold with 100fs broadband pump and Stokes beams,
the Raman coherence is probed using a frequency-narrowed 2.5 ps probe beam that is time
delayed to suppress the nonresonant background by 2 orders of magnitude. Experimental …