Limiting duration of ultrashort optical pulses generated by passively mode-locked solid-state lasers

Steady-state pulsed emission was analyzed taking into account the finite relaxation time of a saturable absorber. The profile of the steady-state optical pulses and the dependences of their duration on the width of the gain band, on the relaxation time of the passive filter, and on the saturation parameters were determined. The results of the theoretical analysis show good agreement with the results of an experiment on the generation of picosecond and subpicosecond optical pulses. These data can be used to assess the prospects for mastering the subpicosecond and femtosecond ranges using currently available saturable absorbers and wide-band solid-state amplifying media.