KERR-LENS MODE-LOCKED LASER MODEL - ROLE OF SPACE-TIME EFFECTS

A spatio-temporal model of a self-mode-locked laser is presented. It u ses a full wave-optics approximation of the propagation in the laser r esonator and includes dispersion, self-phase modulation, and self-focu sing of the intracavity radiation. It is shown that the self-consisten t evolution of the pulse toward steady state imposes strong space-time focusing in the crystal, where both the space and time foci are locat ed. This combined focusing is inherent for Kerr-lens mode-locked laser s with linear and ring cavities, and with and without intracavity satu rable absorbers. It is considered as a general mechanism for compensat ion of space-time astigmatism within the nonlinear resonator. The pred ictions of the model agree very well with the experiment. (C) 1998 Opt ical Society of America.