Stimulated backscattering of light in media with induced anisotropy

An analysis is made of the influence of different polarizations of the exciting and scattered radiations on the stimulated scattering efficiency. This difference may be due to a change in the polarization during the propagation of light under photoelastic birefringence and Faraday effect conditions. The intensity and degree of polarization of backscattered radiation are calculated allowing for spontaneous "seed" sources and an arbitrary relationship between gain and anisotropy. The results of an experimental investigation of stimulated Brillouin scattering of ruby laser radiation in polymethylmethacrylate confirm the theoretical prediction of an increase in the stimulated scattering threshold by a factor of about 2 on application of a mechanical stress to a sample.