THEORY OF PASSIVE-MODE LOCKING OF COLOR-CENTER LASERS BY A FAST SATURABLE ABSORBER

A theoretical model of passive mode locking of colour-center lasers by an effective fast saturable absorber is presented where a hybrid satu ration scheme is applied to consider the interaction of the mode-locke d pulse with the gain medium. Intracavity group-velocity dispersion an d Kerr-type nonlinearity are taken into account and their combined act ion can result in soliton-like pulse shaping and shortening. Chirped s teady-state solutions whose carrier frequency can be shifted with resp ect to the central frequency of the gain are found in a limited range of the parameters specifying the problem.