Single-loss-modulated and dual-loss-modulated compact Nd:Gd3Ga5O12 lasers generating sub-nanosecond laser pulses

We report on a Nd:Gd3Ga5O12 crystal laser formed with a plane-parallel cavity, which could be passively Q-switched with single- or dual-loss modulation, and was capable of generating sub-nanosecond laser pulses. The laser was pumped by an 808-nm pulsed laser diode at a repetition rate of 120 Hz, with pump durations in a range of 100–350 μs. The shortest pulse width achieved in single-loss Q-switching was 461.7 ± 5.5 ps, and the highest peak power could amount to 128.5 ± 5.9 kW. Green laser pulses of 332 ps in width were also obtained through second-harmonic generation with a nonlinear component. In passively Q-switched operation with dual-loss modulation, the minimum pulse width attainable was 767.7 ± 2.5 ps, while the pulse peak power could reach 53.0 ± 6.6 kW.