Generation of electron plasma wave and particle acceleration by beating of two intense cross focused elliptical laser beams in collisionless plasma

Abstract

This paper presents the propagation of two intense cross-focused elliptical laser beams (ELBs) in a collisionless plasma and their effect on the excitation of electron plasma waves (EPWs) and particle acceleration, when relativistic and ponderomotive nonlinearities are operative. Due to the mutual interaction of the two ELBs, cross-focusing takes place in the plasma. An EPW is generated on account of the beating of the two cross-focused ELBs of frequencies ω1 and ω2. Nonlinear differential equations have been set up for the beamwidth parameters of the ELBs, the power of the EPW and the energy gained by the electrons using WKB and paraxial-ray approximations. Numerical simulations have been carried out to investigate the effect of various laser and plasma parameters such as incident laser intensity and plasma density on the focusing of ELBs in plasmas and its effect on the power of excited EPWs and particle acceleration. Numerical results show that the focusing and intensity of both beams in plasma increase with increasing values of incident laser intensity and plasma density. It is observed that the cross-focusing of two ELBs enhances the power of generated EPWs and the yield of energy gain. This study is useful for determining the propagation dynamics of ELBs in plasma and the results are helpful for various applications requiring multiple laser beams.