Effect of carrier heating on diffusion induced modulational instability in semiconductor plasmas

The purpose of the present paper is to report the study on modulational amplification in diffusive semiconductors including hot carrier effects. Considering that the origin of modulational interaction lies in the third-order optical susceptibility χ ⁽³⁾ arising from the nonlinear diffusion current density and using coupled mode theory, an analytical investigation of frequency modulational interaction between co-propagating laser beams and internally generated acoustic mode is presented. We have studied the steady state and transient amplification characteristics of modulated waves arising in diffusive semiconductor plasmas. The effect of carrier heating adds new dimensions to the present study. The heating effect reduces the required threshold amplitude of wave and enhances steady-state as well as transient gain of the generated acoustic mode.