实验研究了以钛宝石薄片作为增益介质的再生激光放大器，其钛宝石薄片厚度为2 mm，前表面作为通光面，镀有对抽运激光和放大激光增透的高阈值双色介质膜，后表面作为反射面，镀有对抽运激光和放大激光高反的高阈值双色介质膜，晶体对抽运激光的吸收率大于80%(1次透射和1次反射)。在再生腔中，钛宝石晶体不仅作为增益介质，也作为反射腔镜，简化了放大腔腔型。钛宝石晶体采用端面冷却的方式，极大地降低了晶体中的热效应，从而提高了放大脉冲激光的光束质量，在此基础上获得了能量为5.2 mJ的放大激光脉冲输出，能量转换效率达到11.5%，放大激光光束质量因子M2小于1.2。

A regenerative amplifier taking a thin disk Tisapphire crystal (2 mm thick) as gain medium is presented. The front face of crystal is anti-reflection (AR) coated at 532 nm and 750~850 nm, the other face is high reflection (HR) coated at 532 nm and 750~850 nm, and the total absorbing efficiency of the crystal is over 80% at 532 nm for double passes. In the regenerative cavity, the Tisapphire crystal also acts as a flat reflective mirror, which reduces the complexity of amplifier. The crystal is end-cooled to reduce the thermal effects and improve the beam quality of amplified laser pulses, as a result, the output energy of the amplified laser is about 5.2 mJ, the corresponding conversion efficiency is 11.5%, and the beam quality factor M2 is less than 1.2.