STIMULATED RAMAN AND BRILLOUIN-SCATTERING PROCESSES IN CENTROSYMMETRIC SEMICONDUCTOR PLASMAS

A simple analytical treatment based on the hydrodynamical model of pla smas is developed to study both steady-state and transient stimulated Raman and Brillouin scattering processes in centrosymmetric or weakly noncentrosymmetric semiconductors. Gain constants, threshold-pump inte nsities, and optimum pulse durations for the onset of Raman and Brillo uin instabilities are estimated. The qualitative behaviour of transien t gain factors is found to be in agreement with the experimental and o ther theoretical observations. The analysis explains satisfactorily th e competition between stimulated Raman and Brillouin processes in the short- and long-pulse duration regimes.