Influence of Szigeti effective charge on coherent Raman scattering of laser radiation in magnetized direct gap semiconductors

Abstract

By considering the hydrodynamic model of semiconductor-plasmas, an analytical investigation is performed to study the influence of Szigeti effective charge (qs) on coherent Raman scattering (CRS) of laser radiation in a transversely magnetized direct gap semiconductor arising from electron density perturbations and molecular vibrations of the medium both produced at the transverse optical phonon frequency. Assuming that the origin of CRS lies in the third-order susceptibility of the medium, an expression is obtained for Raman gain coefficient (gR). Numerical estimates are made for a representative n-type InSb crystal duly shined by pulsed 10.6 μm CO 2 laser. The threshold field (E0 th ) for inciting CRS is identified. The dependence of gR on pump field strength E0, externally applied magnetic field (in terms of electron cyclotron frequency ωc) and doping concentration (in terms of plasma frequency ωp) is reported for both cases viz., qs = 0 and qs ≠ 0. In absence of qs, the results are found to be well in agreement with available literature.