Active and passive Q-switching operation of 1 μm Yb:YSP laser with an optical chopper/AOM and MoWS₂ nanosheets

In this paper, the laser diode (LD)-pumped all-solid-state Yb:YSr₃ (PO₄)₃ (Yb:YSP) lasers with active and passive Q-switching operation were demonstrated for the first time. At the pump power of 5.5 W, the average output power was 369 mW and the single pulse energy was 184.5 μJ at 2 kHz in the active Q-switching operation with an optical chopper. For the acousto-optic modulator Q-switched laser, a 118 ns pulse duration and 2881 W pulse peak power at 0.5 kHz were obtained. Furthermore, MoWS₂ nanosheets were implemented to the passively Q-switched Yb:YSP laser, generating stable pulses with duration of 1.45 μs at the repetition frequency of 55 kHz and verifying the optical response potential of MoWS₂. The good laser beam quality of M x 2 = 1.14 and M y 2 = 1.12 were achieved as well.