STIMULATED BRILLOUIN SCATTERING IN n-TYPE III–V PIEZOELECTRIC SEMICONDUCTORS

Abstract

Based upon the hydrodynamic model of an one-component semiconductor plasma, a detailed analytical study of stimulated Brillouin scattering (SBS) processes in a doped weakly piezoelectric semiconductor has been made following the coupled mode approach. The nonlinear effective polarization and the corresponding third-order optical susceptibility at Stokes frequency for the SBS processes are obtained. The analysis deals with the qualitative behavior of threshold pump electric field required for the onset of SBS and the Brillouin gain with respect to the doping concentration well above threshold. Numerical analysis has been made for n-type InSb crystal duly irradiated by a nanosecond pulsed 10.6 μm CO 2 laser. The influence of piezoelectric properties of the crystal medium on both threshold pump field and Brillouin gain has been explored and it is found that SBS with significant gain at lower threshold pump field could be achieved in the weakly piezoelectric moderately doped n-type semiconductor. The Brillouin gain is noted to be significantly large only over a very narrow doping range. The theoretical analysis shows that the doped III–V semiconductors have a good potentiality in the fabrication of SBS based phase conjugate mirrors with high reflectivity well below the optical damage threshold.