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

Abstract

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.