Spatiotemporal evolution of Gaussian laser beam in a multiply ionized plasma under a weakly relativistic regime

Abstract

Taking relativistic-ponderomotive nonlinearity into account, the dynamics of an intense Gaussian laser pulse propagating in a multi ions plasma has been studied. The modification of the dielectric permittivity of such plasma due to the ponderomotive force of the laser pulse has been derived. The coupled equations governing the laser pulse dynamics in space and time have been achieved and numerically solved, using the complex eikonal function and paraxial ray approximation. The effects of the initial laser intensity, multiply charged ions, specifically singly and doubly charged ions, on the self-focusing and self-compression of the Gaussian laser pulse in the plasma have been investigated. It was found that there is a particular laser intensity range where self-compression can occur. It was further observed that the multiply charged ions improve or weaken the nonlinear effects depending on the initial laser intensity, which leads to the pulse evolution.

Keywords

• laser pulse propagation in plasma
• laser pulse self-focusing
• laser pulse self-compression