2.79 $\mathrm{\mu }$m-band pulsed laser has important application prospects in medicine, military, etc. In this paper, the pulse operation of Er, Cr: YSGG laser Q-switched by piezoelectric crystal La₃Ga₅SIO₁₄(LGS) is realized, and high-energy output under nanosecond pulse is obtained. In the experiment, LGS crystal was used as the de-voltage Q-switching element. At a repetition frequency of 10 Hz, the obtained pulse width was 27.4 ns, the corresponding single pulse maximum output energy was 136 mJ, and the dynamic–static energy conversion efficiency was 75.6%; The output beam quality factor M² obtained by self-made spot analysis software in the $x$ and $y$ directions are 1.34 and 1.40, respectively.

2.79 $\mathrm{\mu }$m波段脉冲激光器在医学、军事等方面具有重要的应用前景。 本文实现了压电晶体La ₃ Ga ₅ SIO ₁₄ (LGS)调Q的Er、Cr：YSGG激光器的脉冲操作，高-获得纳秒脉冲下的能量输出。实验中采用LGS晶体作为降压调Q元件。在10Hz重复频率下，得到的脉宽为27.4ns，对应的单脉冲最大输出能量为136mJ，动静能量转换效率为75.6%；自制光斑分析软件得到的输出光束质量因子 M ²$X$ 和 $是$ 方向分别为 1.34 和 1.40。