Solitary structure formation and self-guiding of electromagnetic beam in highly degenerate electron plasma

Abstract

In the present paper we consider the nonlinear interaction of high frequency intense electromagnetic (EM) beam with degenerate electron plasmas. In a slowly varying envelop approximation the beam dynamics is described by the couple of nonlinear equations for the vector and scalar potentials. Numerical simulations demonstrate that for an arbitrary level of degeneracy the plasma supports existence of axially symmetric 2D solitons which are stable against small perturbations. The solitons exist if the power trapped in the structures, being the growing function of soliton amplitude, is above a certain critical value but below the value determining by electron cavitation. The robustness of obtained soliton solutions was verified by simulating the dynamics of initial Gaussian beams with parameters close to the solitonic ones. After few diffraction lengths the beam attains the profile close to the profile of the ground state soliton and propagates for a long distance without detectable distortion. The simulations have been performed for the input Gaussian beams with parameters far from ground state solutions. It is shown that the beam parameters are oscillating near the parameters of the ground soliton solution and thus the formation of oscillating waveguide structures takes place.