Quadruple Gaussian laser beams in thermal quantum plasma: self-focusing, self-trapping and self-phase modulation

This paper presents a theoretical investigation into the self-action effects of intense laser beams interacting with fusion plasmas. The focus of the study is on the phenomena related to the nonlinear refraction of the laser beam, which are examined in detail. To analyze the impact of illumination uniformity across the beam's phase fronts on its propagation characteristics, the irradiance profile of the beam is modeled using a quadruple Gaussian (Q.G) profile. By employing the variational theory approach, the nonlinear partial differential equation (PDE) governing the beam envelope is transformed into a system of coupled ordinary differential equations that describe the evolution of the beam width and axial phase. These equations are then solved numerically to investigate the influence of both laser and medium parameters on the propagation characteristics of the laser beam.