On the dynamics of ponderomotive filamentation of laser beams in a plasma

Abstract
The influence of ponderomotive force-induced plasma motion on filamentation is examined, using both linear and non-linear descriptions. Although the time asymptote of the process is identical to the stationary convective amplification of filaments, the dynamics of the plasma response may have a serious impact on the transient behaviour of filamentation. The plasma motion contains large amplitude oscillations of inhomogeneities in the laser beam with maxima that substantially exceed the asymptotic value and temporary growth of the very narrow filaments, which cannot be amplified in the stationary approximation.