New method for passive Q switching of an injection laser with an ultrashort absorber recovery time

A new modification of the method of passive Q switching in a semiconductor laser with an isotypic saturable absorber was proposed and implemented. An increase in the power and repetition frequency of ultrashort pulses and a reduction of their duration were achieved by transferring a major fraction of excited carriers from the absorber to an amplifier with the aid of an electric field. Ultrashort pulses of 5 psec duration with a repetition frequency in excess of 18 GHz and a peak power in excess of 10 W (power density 4×10⁸ W/cm² in the active medium) were generated in a multicomponent AlGaAs/GaAs injection heterolaser.