Parametric dispersion and amplification in semiconductor plasmas: Effects of carrier heating

Using the hydrodynamic model of a semiconductor plasma, the influence of carrier heating on the parametric dispersion and amplification has been analytically investigated in a doped III-V semiconductor, viz. n-InSb. The origin of the phenomena lies in the effective second-order optical susceptibility (χe(2)) arising due to the induced nonlinear current density of the medium. Using the coupled-mode theory, the threshold value of pump electric field (|E0T|para) and parametric gain coefficient (αpara) are obtained via χe(2). The relevant experiment has not been performed. Proper selection of the doping level not only lowers |E0T|para required for the onset of parametric excitation but also enhances αpara. The carrier heating induced by the intense pump modifies the electron collision frequency and hence the nonlinearity of the medium, which in turn further lowers |E0T|para and enhances αpara by a factor of ∼103 and ∼2×102, respectively. The results strongly suggest that the incorporation of carrier heating by the pump in the analysis leads to a better understanding of parametric processes in solids and gaseous plasmas, which can be of great use in the generation of squeezed states.