CHARACTERISTICS OF CAVITY ROUND-TRIP TIME PULSES IN SHORT-CAVITY Q-SWITCHED ALGAAS MULTIPLE-QUANTUM-WELL SEMICONDUCTOR-LASERS

In the AlGaAs/GaAs two-section multiple-quantum-well (MQW) laser syste m, Q-switched optical pulses whose width is shelter than the cavity ro und-trip time were obtained by driving the gain section with 200 ps el ectrical pulses. The pulse-width characteristics were measured while v arying the cavity length, and the optimum cavity length for obtaining the shortest optical pulse was found. When the cavity length was 170-2 00 mu m, the shortest optical pulse with a width of 6-8 ps was obtaine d. We also round a profile change in the second-harmonic-generation (S HG) auto-correlation trace when the cavity length was changed.