Self-Focusing and Defocusing of Lorentz-Gauss Laser Beam in Collisionless Plasma

The propagation of Lorentz-Gauss (L-G) Laser beam in collisionless plasma is investigated. Based on WKB and paraxial approximations, coupled differential equations for beam-width parameters in two transverse dimensions of L-G beam are derived under the parabolic equation approach. The self-focusing and self-defocusing characters of L-G beam are numerically demonstrated. The influence of Lorentz width on the propagation of L-G beam through plasma is specifically considered. It is found that the heterogeneous intensity distribution of L-G beam plays a vital role in its propagation dynamics through plasmas.