Enhanced propagation and focusing of an intense laser beam in high density magnetized plasma

Abstract

In the present communication, the steady state propagation of an intense, circularly polarized Gaussian electromagnetic beam in high-density magnetized plasma is studied analytically and numerically. The relativistic oscillation of the mass of the electrons in the field of the pump and longitudinal magnetic field are shown to have a major effect on the dynamics of the propagation of intense electromagnetic wave. The wave equation has been solved under WKB and paraxial approximation by expanding the dielectric tensor for arbitrary large intensity. The propagation of electromagnetic waves in magnetized plasma, in the so-called extraordinary mode has been explicitly considered in the analysis. The variation of beamwidth parameter with distance of propagation has been obtained for chosen values of critical parameters in different regimes. These regimes are steady divergence, oscillatory divergence and self-focusing. Numerical computations are performed for a wide range of dimensionless parameters. It is seen that the laser beamwidth tends to attain a constant value depending upon plasma electron density, axial inhomogeneity and laser irradiance for different strength of magnetic field. Further, enhanced propagation, focusing and penetration of an intense laser beam is evident through plots from slightly underdense to overdense plasma with different types of density profiles.