High-gain Yb:LuPO4 microchip laser passively Q-switched by MoS2 or WS2 deposited on a sapphire etalon output coupler

We report on a Yb:LuPO4 microchip laser that is able to be passively Q-switched with few-layer WS2 or MoS2 deposited on its sapphire etalon output coupler. With 11.9 W of pump power absorbed, an average output power of 2.34 W is produced at a pulse repetition rate of 1.43 MHz with a slope efficiency of 31%, in WS2 passive Q-switching; the pulse energy, duration, and peak power are respectively 1.64 mu J, 34 ns, and 48.2 W. While passively Q-switched by MoS2, the laser can generate an average output power of 1.57 W at a repetition rate of 1.27 MHz, with the shortest pulse duration of 39 ns. Our work provides a novel simple way of making compact, reliable, high-repetition-rate pulsed lasers capable of producing multi-watt output power with several tens ns of pulse duration. (C) 2018 Optical Society of America under the terms of the OSA Open Access Publishing Agreement.