Self-focusing Of cosh-Gaussian Beam Research Articles

Effect of an external magnetic field on the self-focusing of a cosh-Gaussian laser beam in plasma under the relativistic-ponderomotive effect

This work presents an analytical and numerical study of the relativistic-ponderomotive effect on self-focusing of an intense cosh-Gaussian laser beam in a collisionless magnetized plasma by considering an external magnetic field in the direction of propagation of the laser beam. The nonlinear differential equation for the beam width parameter/intensity of a cosh-Gaussian laser beam in a magnetized plasma is obtained by Wentzel–Kramers–Brillouin (WKB) and paraxial-ray approximations. The self-focusing of the cosh-Gaussian beam at different values of the magnetic field parameter is investigated. The results have also been compared to relativistic nonlinearity. The results show that the self-focusing effect of cosh-Gaussian beam in magnetized plasma becomes stronger, when relativistic and ponderomotive nonlinearities acts together. In addition, the self-trapping of cosh-Gaussian beam in magnetized plasma has also been studied. Numerical results are presented for the well-established laser and plasma parameters.

Influence of self-focused high power Cosh-Gaussian beam on second harmonic generation in cold quantum plasma

The objective of present work is to investigate influence of self-focused high power Cosh-Gaussian (ChG) beam on second harmonic generation (SHG) in cold quantum plasma (CQP). WKB and Paraxial approximations are utilized for acquiring 2nd order differential equation representing propagation characteristics of ChG beam with normalized propagation distance. The modification in dielectric function of plasma is observed on account of relativistic nonlinearity causing self-focusing of ChG beam. The density gradients are produced in transverse direction. These density gradients cause electron plasma wave (EPW) excitation at main wave frequency. Further, the nonlinear interaction between pump wave and excited EPW produces 2nd harmonics in plasma. We have performed numerical simulations for exploring impact of various laser & plasma parameters on beam waist of ChG beam and conversion efficiency of 2nd harmonics. We have also made the comparison of given work with classical relativistic plasma (CRP) regime.

Self-focusing of asymmetric cosh-Gaussian laser beams propagating through collisionless magnetized plasma

AbstractIn this paper, self-focusing of asymmetric cosh-Gaussian laser beams in collisionless magnetized plasma has been studied. The non-linearity in dielectric constant considered herein is mainly due to the ponderomotive force. The non-linear coupled differential equations for the beam width parameters in transverse dimensions of the beam have been obtained by using WKB and paraxial approximations under parabolic equation approach. The numerical computation is completed by using fourth-order Runge–Kutta method. The effect of unlike decentered parameters in both transverse dimensions of the beam on self-focusing of cosh-Gaussian beams has been presented. Further, the effect of the static magnetic field and polarization modes of the laser has been explored.