内腔式非稳腔DF激光光束质量研究  

Study on beam quality of DF laser with inner cavity unstable resonator

作　　者：阮鹏[1] 汪玉海[1] 潘其坤[2] 邵春雷[2] 陈飞[2] 郭劲[2] RUAN Peng;WANG Yu-hai;PAN Qi-kun;SHAO Chun-lei;CHEN Fei;GUO Jin(College of Information Technology,Jilin Normal University,Siping 136000,China;Changchun Institute of Optics,Fine Mechanics and Physics,Chinese Academy of Science,Changchun 130033,China)

机构地区：[1]吉林师范大学信息技术学院,吉林四平136000 [2]中国科学院长春光学精密机械与物理研究所,吉林长春130033

出　　处：《中国光学（中英文）》2024年第5期1068-1074,共7页Chinese Optics

基　　金：吉林省自然科学基金项目(No.20220101207JC);激光与物质相互作用国家重点实验室开放基础研究课题(No.SKLLIM2115)。

摘　　要：激光光束质量是衡量激光器应用性能的重要指标之一,面向远距离光电对抗应用场景,本文开展了非链式脉冲氟化氘(DF)激光器非稳腔设计和光束质量提升技术研究。设计了3组不同放大倍率的正分支虚共焦非稳腔,搭建了凸面腔镜横向和轴向两种支撑结构的非稳腔实验装置,其中横向支撑结构内置循环水冷却通道。以86.5%环围能量定义激光光斑大小,选用β因子评价激光光束质量,比较两种支撑方式下的输出能量和光束质量。研究发现:相同条件下,轴向支撑结构的非稳腔输出能量较横向支撑结构高6%,但远场发散角较横向支撑大9%;水冷横向支撑结构虽存在部分能量遮挡,但其较好的热稳定性显著提升了激光光束质量。在M=2.25的横向支撑内腔式非稳腔条件下获得了光束质量因子β=1.83、发散角θ_(0.865)=0.63 mrad的激光光束。该条件下的激光单脉冲能量为2.34 J,激光脉宽为88.2 ns,峰值功率达到26.5 MW。Laser beam quality is one of the key indicators to measure the application performance of laser.To meet the application requirements of long-distance optoelectronic countermeasures,we cany out the research on the design of unstable resonators and beam quality improvement techniques for non-chain pulsed deuterium fluoride(DF)lasers.Three sets of positive branch virtual confocal unstable resonators with different magnifications are designed.An inner cavity unstable resonator with two support structures of convex mirror,transverse support and longitudinal support,are constructed.The transverse support structure is equipped with a circulating water-cooling channel.Using 86.5% surrounding energy to define laser beam diameter,the laser beam quality is evaluated with beam quality factorβ,and the energy and beam divergence for two support types of convex mirrors are compared.It can be found that,under the same conditions,the laser energy of unstable resonators with longitudinal support is 6% higher than that of the transverse support structure,but the far-field divergence angle is 9% larger than that of the transverse support structure.Although the watercooled transverse support structure has energy shielding,its good thermal stability significantly improves the quality of the laser beam.Laser beam with a beam quality factor β of 1.83 and a divergence angle θ_(0.865) of 0.63 mrad is obtained under the transverse support unstable resonator of M=2.25.Under this condition,the laser single pulse energy is 2.34 J,the laser pulse width is 88.2 ns,and the peak power reaches 26.5 MW.

关 键 词：DF激光器 内腔式 虚共焦非稳腔 光束质量 

分 类 号：TN248.5[电子电信—物理电子学]