The theory of passive Q-switching of solid-state lasers with slow-relaxing solid-state saturable absorbers is investigated in this paper. Passive Q-switching performance of the Cr:BeAl2O4 laser with the Cr:YSO solid-state saturable absorber is numerically studied. With typical optical pumping, output coupling, and saturable absorber doping concentration, an energy output of more than 200 mJ in a laser pulse duration of less than 30 ns may be obtained.
