为了获得高效率3 μm~5 μm中红外激光输出，利用电光调Q晶体RbTiOPO4(RTP)，通过高重复频率驱动调Q同步技术和LD侧面泵浦技术，获得高重频窄脉宽1.06 μm激光输出，泵浦非线性晶体周期极化钽酸锂(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20 A、调Q驱动频率10 kHz的条件下，获得15 W的1.06 μm激光。利用该1.06 μm激光泵浦PPLT获得最高功率为2.6 W的3.9 μm中红外激光，1.06 μm到3.9 μm的转化效率为17.3%。实验结果表明：通过高重频电光调Q技术和LD侧面泵浦技术，可以实现高重频窄脉宽1.06 μm偏振光输出，泵浦PPLT可获得高功率高效率3.9 μm中红外激光输出。

To acquire high efficiency middle wave infrared(MWIR) laser of 3 μm~5 μm，the high repetition rate driving electro-optic Q-switched synchronization technology and LD side-pumped technology were used to get high repetition rate laser output with 1.06 μm narrow width. Periodically poled lithium tantalate (PPLT) was pumped to achieve high-power MWIR laser output of 3 μm ~5 μm. As the input current was 20 A and the Q-switched frequency was 10kHz, the 1.06 μm laser with 15 W power was obtained. After pumping PPLT by the laser, the 3.9 μm laser with maximum power of 2.6 W was got. The conversion efficiency from 1.06 μm to 3.9 μm was 17.3%. Experiment results indicate that the high repetition rate driving electro-optical Q-switched technology and LD side-pumped technology can be used to obtain high-repetition narrow-width 1.06 μm polarized laser, and pumping PPLT can obtain high-power high-efficiency 3.9 μm MWIR laser.