低温重复率Yb：YAG 固体激光放大器

Cryogenic Yb：YAG solid state pulsed laser amplifier

摘要: Yb：YAG晶体比Nd：YAG晶体更适用于产生和放大具有Hz量级重复频率的高脉冲能量激光。报道了LD泵浦低温工作的Yb：YAG脉冲固体激光放大系统。整个系统由再生种子源、预放大器和主放大器3部分组成。晶体用铟和金箔作为导热层压到金属热沉上，散热方式采用传导冷却，低温环境由液氮冷却热沉来保证。实验结果表明：当晶体温度控制在150 K时，装置得到了3 J@10 ns，10 Hz的1 030 nm脉冲激光能量输出。研究了低温真空环境下介质膜的损伤等因素对泵浦参数的要求，最后分析了进一步提升脉冲能量所需要解决的问题。

Abstract: Compared with Nd:YAG, the Yb:YAG laser system is more suitable to produce at several Hz repetition rates high pulsed energy laser beam. A LD pumped Yb:YAG solid state pulsed MOPA laser system at cryogenic temperature was reported. The amplifier chain was composed of three parts: regenerative amplifier seed, pre-amplifier and main amplifier. The thermal management was realized by liquid nitrogen cooling sink on which laser crystal was compressed using indium and gold foil as thermal interface. The coating film damage at cryogenic and vacuum environment was studied, which directly affected the pumped and extracted parameter design. A 1 030 nm pulse 10 Hz, 10 ns laser output energy 3 J was achieved. At last, in order to improve laser energy scalability the further step was analyzed.