Binary phase shaping for selective single-beam CARS spectroscopy and imaging of gas-phase molecules



We report on mode-selective single-beam coherent anti-Stokes Raman scattering spectroscopy of gas-phase molecules. Binary phase shaping (BPS) is used to produce single-mode excitation of O2, N2, and CO2 vibrational modes in ambient air and gas-phase mixtures, with high-contrast rejection of off-resonant Raman modes and efficient nonresonant-background suppression. In particular, we demonstrate independent excitation of CO2 Fermi dyads at ∼1280 and ∼1380 cm−1 and apply BPS for high-contrast imaging of CO2 jet in ambient air. Copyright © 2010 John Wiley & Sons, Ltd.