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

The propagation of a relativistically intense short laser pulse into an iso tropic 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 equ ation of the spectral function is used along with the set of equations of t he plasma to derive a general dispersion relation, where relativistic effec ts play an important role. In the case of a superstrong short laser pulse, Langmuir waves, with phase velocities larger than the speed of light, and w aves of ion-sound type, which are damped only on ions, are found. In additi on, for the case when the plasma density along with the mass of the electro ns satisfies the "frozen-in" condition, stationary nonlinear new type of io n-sound waves are investigated. The mechanism of the emission of these wave s is also discussed. [S1063-651X(99)01112-5].