100–300 Hz repetition-rate acousto-optic Q-switched 2.79 μm Er:YSGG laser side-pumped by laser-diode

An LD-pumped high-repetition-rate Er:YSGG laser utilizing a TeO2 crystal as an acousto-optic Q-switch is proposed and demonstrated. The thermal lensing effect caused by the high-repetition-rate pump is compensated by a plano-convex laser resonator. As a result, a Q-switched 2.79 μm laser with a repetition rate of 100–300 Hz is obtained. When a 100 Hz repetition rate, a 1 mJ pulse energy and a 76 ns pulse duration are employed, the corresponding peak power is 13.2 kW. To the best of our knowledge, this laser offers the highest pulse energy among Q-switched 2.79 μm lasers with pulse repetition rates above one hundred hertz.