Abstract

An investigation of the spatiotemporal dynamics of a quadruple Gaussian laser beam via plasma in the presence of an external magnetic field characterized by ponderomotive and relativistic nonlinearities is presented. The moment theory approach is used to study the second-order nonlinear differential equation analytically and numerically. The evolution of the beam width parameter determines the pulse dynamics, in both time and space. The spatial evolution at different pulse times of a quadruple Gaussian laser beam in a relativistic ponderomotive magnetized plasma is reported. The effects of initial laser parameters, such as lateral beam separation, laser intensity, external magnetic field, plasma density, and time factor on self-focusing, are studied. Strong periodic self-focusing is observed for a gradual increase in the magnetic field, plasma density, and time factor, whereas an increase in beam intensity shows reversal effects. The phenomenon of self-trapping is also observed for different values of lateral beam separation and magnetic field. A three-dimensional portrait of the normalized intensity as a function of the normalized radial co-ordinate and lateral beam separation is well illustrated. It is useful in studying inertial confinement fusion.

© 2020 Optical Society of America