Propagation of short intense laser pulses in plasma channels

Summary form only given. Finite pulse length effects play a major role in the propagation of intense laser beams in a preformed plasma channel. An envelope equation is derived which describes the dynamics of short laser pulses in plasma channels including nonlinear effects. The nonlinear terms arise from relativistic and atomic (bound) electron effects. The laser field is shown to be significantly modified for pulses less than a few tens of wavelengths long. Short laser pulses in plasma channels are found to undergo an envelope oscillation in which the front of the pulse is always damped while the back initially grows. The envelope modulation on the pulse eventually damps due to frequency spread phase mixing. In addition, finite pulse length effects are shown to significantly modify nonlinear focusing processes.