CARS SPECTRA OF HCL, N-2, AND C2H2 IN THE GAS-PHASE

Coherent anti-Stokes Raman scattering (CARS) spectra of HCl, N-2, and the nu(1) fundamental of C2H2 have been measured in the gas phase. The measured spectra show rotational structures which originate from the Q-branch transitions. The spectra have successfully been simulated wit h proper selection rules, line positions, and relative intensities fro m room temperature Boltzmann population distributions. The vibration-r otation interaction constant alpha of HCl in the ground electronic sta te has been measured from the rotationally resolved CARS spectra which is alpha=0.3076 cm(-1). Possibilities of optical pumping and of measu ring state specific energy distributions of molecules are discussed.