Filamentation of laser in an inhomogeneous plasma

Abstract

Filamentation of an intense short pulse laser in an inhomogeneous plasma is investigated when laser propagates along the direction of density gradient and nonlinearity arises due to the relativistic mass variation and ponderomotive force. The ion motion is neglected; however, the effect of dielectric swelling is included. The inhomogeneity in the density profile introduces dielectric swelling of the pump intensity enhancing the plasma permittivity and the growth rate of the instability. The perturbation in laser amplitude grows faster than exponential as the laser penetrates deeper into the denser plasma.