Passively Q-switched microlaser performance in the presence of pump-induced bleaching of the saturable absorber.

Unabsorbed pump light in passively Q-switched microlasers leads to suboptimal pulse generation by bleaching the saturable absorber. This mechanism increases the effective unsaturated transmission of the absorber, which leads to a change in the system dynamics that results in increased pulse durations and decreased pulse energies. We report experimental evidence of pump-induced bleaching of the saturable absorber, an increase in the pulse duration from 360 to 880 ps, and develop a simple analytical treatment that includes this effect within the framework of existing passive Q-switching models.