Effective self-mode-locking of cw solid-state lasers with a resonant nonlinearity in an additional cavity

A fluctuation model of the operation of a cw solid-state laser with an additional cavity containing a saturable absorber is used to identify the effective self-mode-locking ranges which are closed areas when plotted in terms of the laser parameters. The main features of effective mode locking are related to the behaviour of the transmission of the additional cavity, considered as a function of the field intensity. It is shown that a resonant nonlinearity ensures effective mode locking both in the absence of interferometric matching of the cavity lengths and in the presence of a 'macromismatch' of their lengths when the delay of the field from the additional cavity relative to the lasing pulse is comparable with the pulse duration.