DIFFUSION-INDUCED MODULATIONAL INSTABILITY IN SEMICONDUCTOR QUANTUM PLASMA WITH STRAIN DEPENDENT DIELECTRIC CONSTANT

In the present paper we report the diffusion-induced modulational instability (MI) of an intense laser beam in materials (BaTiO₃) with high dielectric constant using quantum hydrodynamic model of plasmas including Bohm potential and Fermi degenerate pressure. For the study of modulation interaction, we have considered that the origin of this nonlinear interaction lies in the third order nonlinear electrical susceptibility arising due to diffusion-induced nonlinear current density and strain dependent polarization of the medium. We have studied the qualitative behavior of parametric dispersion, gain profile and threshold value of pump field with respect to different parameters. It is found that due to the quantum effect the growth rate of MI in the limited range of parameters increases and required threshold amplitude of wave reduces. Hence the result of this analysis would be useful in designing acousto-electric modulators.