Strong self-focusing of an intense cosh-Gaussian laser beam in magnetized plasma under relativistic effect

This work presents the self-focusing of an intense cosh-Gaussian laser beam in a magnetized plasma under relativistic nonlinearity. The field distribution of the beam in the plasma is expressed as the beam width parameter (f0) and the decentered parameter (b). The magnetic field is applied in the direction of propagation of the laser field. The nonlinear differential equation for the beam width parameter of the cosh-Gaussian laser beam is established by following the Wentzel–Kramers–Brillouin (WKB) and higher-order paraxial approximations. The self-focusing of a cosh-Gaussian beam is studied at various values of the decentered parameter of the beam, magnetic field, relative plasma density and incident laser intensity. The results are presented for the established set of laser and plasma parameters. Numerical results suggest that these parameters play a major role in the stronger and earlier self-focusing of cosh-Gaussian laser beam in the plasma. The results have also been compared with the paraxial-ray approximation and the Gaussian profile of the laser beam. In addition, the self-trapping of the beam is studied under various parameters.