Stimulated Raman scattering in weakly polar narrow band-gap magnetized semiconductors in the presence of hot carriers

Abstract

Using the hydrodynamic model of semiconductor plasmas, a detailed analytical investigation is made to study both the steady-state and transient Raman gain in a weakly polar narrow band-gap magnetized one-component semiconductor, viz. n-InSb under off-resonant laser irradiation. Using the fact that origin of stimulated Raman scattering (SRS) lies in the third-order (Raman) susceptibility ($\chi_{R}^{(3)}$) of the medium, we obtained an expression of the threshold pump electric field ($E_{th}$), the resulting gain coefficients (steady-state as well as transient $g_{R,TR}$) and optimum pulse duration ($\tau_{p}$) for the onset of SRS. The application of a strong magnetic field not only lowers $E_{th}$ but also enhances $g_{R,TR}$. The carrier heating by the intense pump modifies the electron collision frequency and hence the nonlinearity of the medium which in turn enhances $g_{R,TR}$ significantly. The enhanced $g_{TR}$ can be greatly used in the compression of scattered pulses. The results of the present investigation leads to the better understanding of SRS process in solid and gaseous plasmas and also help considerably in filling the existing gap between theory and experiments.