Propagation of two intense cosh-Gaussian laser beams in plasma in the relativistic-ponderomotive regime

This work presents an investigation of the propagation of two intense cosh-Gaussian laser beams (CGLBs) in collisionless plasma taking into account the combined effects of relativistic and ponderomotive nonlinearities. Due to mutual interaction of two CGLBs, the self-focusing of one beam is affected by the presence of another beam in plasma, and cross-focusing takes place. A paraxial-like approach has been used to investigate the cross-focusing of CGLBs in plasma. An appropriate expression for the nonlinear dielectric constant of plasma has been evaluated in the presence of relativistic-ponderomotive force and used to study the propagation of CGLBs in plasma. The effect of various well-established laser and plasma parameters on the cross-focusing of two beams in plasma has been explored and the results are compared with only relativistic nonlinearity and the Gaussian profile of laser beams. Numerical results show that the decentered parameter (b) plays a crucial role in the cross-focusing of the CGLBs. It is observed that CGLBs focused earlier than Gaussian beams. This study is useful in beat wave excitation of electron plasma wave and collective laser particle accelerators. (C) 2016 Optical Society of America