Excitation of Electron Plasma Wave by Beating Two Copropagating q-Gaussian Laser Beams in Thermal Quantum Plasma: Relativistic Effects
Naveen Gupta, Rohit Johari and Sandeep Kumar
Excitation of an electron plasma wave (EPW) by beating two intense q-Gaussian laser beams has been analyzed in thermal quantum plasma. Moment theory in W.K.B approximation has been invoked to find numerical solution of nonlinear Schrödinger equation for Drude model of dielectric function of plasma. The effect of relativistic increase in electron mass on propagation dynamics of laser beams has been incorporated. The laser induced nonlinearity in the dielectric properties of plasma depends not only on the intensity of the first beam but also on that of second beam. Therefore, propagation characteristics of one laser beam affects that of second beam and hence, cross-focusing of the two laser beams takes place. Due to nonuniform intensity distribution along the wavefronts of the laser beams, the background electron concentration gets modi ed. The amplitude of EPW, that depends on the background electron concentration, thus gets nonlinearly coupled with the laser beams. Numerical simulations have been carried out to investigate the effects of laser-plasma parameters on cross-focusing of the laser beams and further its effect on power of EPW.
Keywords: q-Gaussian, Beat Wave, Quantum Plasma, Self Focusing