Tunable high-repetition-rate pulse generation via passive Q-switched semiconductor laser

An electrical-pumped passive Q-switched semiconductor laser at 1.5 mu m is reported. The high-speed and tunable repetition rate, small footprint (0.47 mm(2)), and low cost demonstrate its unparalleled advantages than traditional solid-state Q-switched laser. Under the voltage-dominated tuning scheme, the maximum repetition rate of the obtained pulses is 4 MHz, with the pulse duration of 0.1 mu s and peak power of 84 mW. Under the current-dominated tuning scheme, the maximum repetition rate of the obtained pulses is 1.85 GHz, with the pulse duration of 0.14 ns and peak power of 120 mW. Furthermore, the maximum energy consumption of this optical pulse source is only 750 mW, which is much lower than solid-state Q-switched pulse lasers (external pumping + water-cooled temperature controlling). It may provide a feasible optical pulse source for miniaturized eye-safety LiDAR.