Laser optical saturation of molecular reorientation in Raman light scattering

Raman scattering by molecules and macromolecules, arrayed in the electric field of an intense laser beam, is analyzed. Nonlinear changes in the intensity of light scattered by linear and symmetric‐top molecules are calculated and expressed in terms of even‐order generalized Langevin reorientation functions for all types of Raman‐active vibrations. It is shown that the Raman line intensity can undergo an abatement or an enhancement as a result of reorientation, induced by laser radiation; the analysis of these changes in intensity provides additional information on the Raman polarizability tensor, particularly on the sign and magnitude of its anisotropy.