A quantitative description of the gain profile of stimulated Brillouin scattering (SBS) in a diffusion-driven electrostrictive semiconducting medium and an analysis of the phase-conjugated signal induced by the SBS process is presented. The analysis is based on the coupled-mode theory and is confined to the acoustoelectric regime of a semiconductor. The third-order nonlinear susceptibilities of the semiconductor, χ(3), are derived analytically, and the conditions for achieving favorable Brillouin gain and SBS-induced phase conjugation are discussed. The threshold field required for the onset of SBS and the optimum interaction length required for phase conjugation are determined also. The effect of drift and diffusion on the scattering process that is due to excess carrier concentration are investigated. The dependence of the SBS gain and the reflectivity of the conjugate signal on the carrier concentration and the acoustic-wave frequency is investigated both analytically and numerically. The magnitude of χ(3) is found to agree with the theoretical and experimental values for type III–V semiconductors.
© 1994 Optical Society of America
A. Neogi, "Stimulated Brillouin scattering in diffusion-driven semiconductors," J. Opt. Soc. Am. B 11, 2246-2251 (1994)