Optical guiding of q-Gaussian laser beams in radial density plasma channel created by two prepulses: ignitor and heater

摘要

Abstract Self-action effects (self focusing) and self phase modulation of q-Gaussian laser beam in plasma channel created by ignitor heater technique have been investigated theoretically. The ignitor beam causes tunnel ionization of air. The heater beam heats the plasma electrons and establishes a parabolic channel and also prolongs the channel life by delaying the electron ion recombination. The third beam (q-Gaussian beam) is guided in the plasma channel under the combined effects of density nonuniformity of the parabolic channel and relativistic mass nonlinearity of the plasma electrons. Formulation is based on finding the numerical solution of nonlinear Schrodinger wave equation (NSWE) for the fields of incident laser beams with the help of moment theory approach. Particular emphasis is put on dynamical variations of the spot size of the laser beams and longitudinal phase-shift of the guided beam with distance of propagation.