Stationary periodic and solitary waves induced by a strong short laser pulse.

Abstract

The propagation of a relatively intense short laser pulse into an isotropic plasma is described. A kinetic equation for the spectral function of the electromagnetic waves is derived for an arbitrary amplitude pump wave, where the fully relativistic case is considered. The resulting kinetic equation of the spectral function is used along with the set of equations of the plasma to derive a general dispersion relation, where relativistic effects play an important role. In the case of a super-strong short laser pulse, Langmuir waves, with phase velocities larger than the speed of light, and waves of ion-sound type, which are damped only on ions, are found. In addition, for the case when the plasma density along with the mass of the electrons satisfies the "frozen-in" condition, stationary nonlinear new type of ion-sound waves are investigated. The mechanism of the emission of these waves is also discussed.