ELECTRON JETS PRODUCED BY ULTRASHORT LASER-PULSES

The mechanism of fast particle generation by a single p-polarized lase r beam of ultrashort pulse duration is analyzed analytically for arbit rary angle of incidence. Nonlocal electron transport that is first and second order in the driving fields is identified as being responsible for the production of groups (jets) of fast particles. It is demonstr ated that nonlocal second-order transport produces electron jets twice per cycle while nonlocal first-order transport produces jets only onc e per cycle. The electron energies obtained by first-order transport c an considerably exceed those obtained by second-order transport. The n on-Maxwellian structure of the time-resolved electron distribution fun ction is given. (C) 1996 Optical Society of America