Influence of the polarization of radiation on the energy characteristics and threshold of stimulated Raman scattering due to rotational transitions

It is shown experimentally and theoretically that the threshold intensity for stimulated Raman scattering (STRS) due to rotational transitions depends strongly on the polarization of the pump radiation. The threshold for rotational STRS is lowest for circularly polarized radiation and increases sharply for linearly polarized radiation. The results of investigations of the energy characteristics of rotational STRS on the degree of ellipticity of the pump radiation are presented.