Electron plasma wave excitation by two co-propagating super-Gaussian laser beams in collisional nanocluster Plasma

Abstract

In this theoretical study, we investigate the electron plasma wave excitation (EPW) by two copropagating high power laser beams in collisional nanocluster plasma. The interaction of electric field profile of laser beams causes the ionization of nanocluster and very quickly it converts into the plasma plume balls. The electric field profile of each super-Gaussian laser beam imparts the oscillatory velocity to the electron associated with nanoclustered plasma. The copropagating laser beams generate the nonlinear ponderomotive force to electrons at beat wave frequency Ï=Ï₁-Ï₂ and wave number k=k₁-k₂ . This nonlinear ponderomotive force drives the self-consisted space charge field and it might have much potential to excite the electron plasma wave in nanoclustered plasma. The expression of electron plasma wave electrostatic potential is derived in nanoplasma medium with considering the electron-ion collision effect. The effective surface plasmons resonance at the surface of nanoclustered plasma plays a crucial role for excitation process. The electron plasma wave excitation is tuned and controlled by varying the super-Gaussian index, cluster radius, density, laser beat wave frequency, laser beam width and collisional frequency. The electron plasma wave excitation might be applicable in nonlinear phenomena such as self-focusing and anomalous absorption.