No abstract

In this paper, self-focusing of finite Airy–Gaussian (AiG) laser beams in collisionless plasma has been investigated. The source of nonlinearity considered herein is relativistic. Based on the Wentzel–Kramers–Brillouin (WKB) and paraxial-ray approximations, the nonlinear coupled differential equations for beam-width parameters in transverse dimensions of AiG beams have been established. The effect of beam's modulation parameter and linear absorption coefficient on the self-focusing/defocusing of the beams is specifically considered. It is found that self-focusing/defocusing of finite AiG beams depends on the range of modulation parameter. The extent of self-focusing is found to decrease with increase in absorption.

In this paper, the propagation of Gaussian laser beam in underdense and magnetized plasma has been studied. The effect of oblique external magnetic field on self-focusing of laser is specifically explored. An envelope equation governing dependence of beam-width parameter with dimensionless distance of propagation of laser is derived by adopting parabolic equation approach under WKB and paraxial approximations. It is found that increasing the angle between the laser beam magnetic field and external magnetic field decreases the self-focusing of laser propagating through plasma.