Collisional shifting and broadening coefficients for the rovibrational anisotropic lines of the ν1/2ν2 fermi dyad in CO2 gas studied by stimulated Raman spectroscopy

Abstract

High-resolution stimulated Raman spectroscopy was applied to the study of collisional broadening and shifting for rovibrational anisotropic Raman lines of the Fermi dyad of molecular carbon dioxide. The O(J) lines of the ν1 band and the S(J) lines of the 2ν2 band were recorded at 295 K. The pressure-induced line shifts were obtained and compared with the overall shift of the high-density Raman Q-branch. A rotational quantum number dependence of the rovibrational line broadening coefficients was observed. The experimental line broadening coefficients were used in order to check the ability of two theoretical methods (random phase approximation and sum rule) for calculating the line broadening coefficients in anisotropic Raman scattering. © 1998 John Wiley & Sons, Ltd.