为了获得高功率高效率3 μm～5 μm中红外激光输出，利用双声光调Q晶体，通过高重复频率驱动调Q同步技术和LD侧面泵浦双棒串接技术，获得高功率高光束质量1.06 μm激光双端输出，外置起偏器获得4束激光输出，利用波片偏振旋光原理，实现4束偏振态一致的激光输出，泵浦非线性晶体PPLT进行频率变换，实现高功率3 μm～5 μm中红外激光输出。在电源输入电流30 A、调Q驱动频率10 kHz的条件下，获得最高功率10.6 W的3.9 μm中红外激光，1.06 μm～3.9 μm转化效率为9.5%。实验结果表明：通过双声光调Q技术和LD侧面泵浦双棒串接技术，可以实现4束高重复频率窄脉宽1.06 μm偏振激光输出，泵浦PPLT可获得高功率3.9 μm中红外激光输出。

To acquire high power and high efficiency mid-infrared laser output, using double acousto-optic Q-switched crystal, through high repetition rate drive Q-switched synchronization technology and LD-side-pumped two-rod series connection technology, high power and high beam quality 1.06 μm laser two-port output was acquired, laser output of four beams was got by exterior polarizer. Using wave-plate polarization rotation principle, consistent polarization laser output of four beams could be realized, PPLT was pumped to get high power 3 μm~5 μm Mid-IR laser output. As the input current was 30 A and the Q-switched frequency was 10 kHz, the highest out power of 3.9 μm laser was 10.6 W, conversion efficiency of 1.06 μm ~3.9 μm laser was 9.5%. Experiment results indicate that using double acousto-optic Q-switched technology and LD-side-pumped two-rod series connection technology, high repetition 1.06 μm polarizer laser output of four beams can be realized, and pumping PPLT can gain high power 3.9 μm mid-infrared laser output.