Evolution of spot-size of lowest-order Bessel-Gaussian laser beams in plasma with relativistic-ponderomotive nonlinearity

In this work, the nonlinear propagation of lowest-order Bessel-Gaussian (B-G) laser beams through plasma is analyzed. The B-G laser beams induce modifications in the dielectric function of plasma through relativistic-ponderomotive interaction. The nonlinear differential equation for the beam-width parameter of lowest-order B-G beams is derived under WKB and paraxial approximations. The numerical appreciation of results is completed by solving the evolution equation for the beam-width parameter of B-G beams by using the fourth-order Runge-Kutta method for the initial plane wavefront of the beam. The numerical computations are presented and discussed in the form of graphs for typical values of laserplasma parameters. It is found that the transverse component of the wave parameter, plasma frequency, and temperature of plasma electrons play a vital role in the spot size evolution of B-G beams in plasma. The present study is a generalization of some previous works. Consequently, the propagation dynamics of a Gaussian beam in plasma described by relativistic-ponderomotive nonlinearity is deduced as a particular case of reference.