Direct measurement of CO2S-branch Raman linewidths broadened by O2, Ar, and C2H4.

Abstract

Direct measurements of CO2S-branch Raman coherence-decay lifetimes resulting from CO2-O2, CO2-Ar, and CO2-C2H4 collisions by employing time-resolved picosecond rotational coherent anti-Stokes Raman scattering (CARS) spectroscopy are reported. Based on the measured Raman coherence dephasing rates, the corresponding Raman linewidths of various J levels are obtained. Our measured linewidth data will aid CO2 CARS fitting, which is applied to the high-accuracy extraction of temperature and species concentration information from CARS spectra.