非链式脉冲DF激光器非稳腔设计与实验研究  

Design and Experimental Investigation on Unstable Resonator for Non-Chain Pulsed DF Laser

作　　者：谭改娟[1,2] 谢冀江[1] 潘其坤[1,2] 邵春雷[1] 张传胜[1] 阮鹏[1,2] 郭劲[1] 

机构地区：[1]中国科学院长春光学精密机械与物理研究所激光与物质相互作用国家重点实验室,吉林长春130033 [2]中国科学院大学,北京100049

出　　处：《中国激光》2014年第1期15-20,共6页Chinese Journal of Lasers

基　　金：科技部国际合作专项基金(2011DFR10320)

摘　　要：采用正支虚共焦腔型对非链式脉冲DF激光器进行非稳腔参数设计并开展实验研究,通过与平凹型稳定腔的对比,揭示了非稳腔在压缩激光远场发散角、提升光束质量方面的显著优势。选取能体现远场能量集中度以及实际光束与理想光束偏移程度的衍射极限倍数β为光束质量评价参数,实验中以86.5%环围能量定义光斑大小,并利用90-10刀口法测量光斑尺寸。通过对不同放大率及模体积的9组非稳腔实验结果的对比,得到了设计优化非稳腔结构参数的规律。综合输出能量、远场发散角、衍射极限倍数β三方面因素,得到了最佳非稳腔参数为放大率M=1.89,后反射镜口径D=40mm,此时激光远场发散角(全角)为0.74mrad,β=1.35,输出能量为1.86J,峰值功率为16.4MW。By employing positive branch confocal unstable resonator, design of cavity parameters and experimental research on non-chain pulsed DF laser are carried out. The advantages of suppressing divergence angle and improving beam quality are shown by comparing plano-concave stable resonator with unstable resonator. To estimate the beam quality, diffraction limit magnification β is chosen as evaluating criterion, which can incarnate both the energy focusing degree and divergence angle excursion. 86.5% enveloping energy is used to define spot size, and 90-10 knife edge method is adopted to measure it. Nine sets of mirrors with different magnifications and mode volumes are tested and compared, and optimization method of unstable cavity parameters is concluded. Taking energy, divergence and diffraction limit magnification into account, the optimal parameters are M=1.89, D=40 mm. Laser beam with divergence angle of 0.74 mrad, β=1.35, laser energy of 1.86 J, and peak power of 16.4 MW is obtained at these parameters.

关 键 词：激光器 DF激光器 正支虚共焦非稳腔 衍射极限倍数 刀口法 

分 类 号：TN242[电子电信—物理电子学] TN248.5