基于微透镜阵列匀束的激光二极管面阵抽运耦合系统分析  

Analysis of laser diode array pump coupling system based on microlens array

作　　者：严雄伟[1] 王振国[1] 蒋新颖[1] 郑建刚[1,2] 李敏 荆玉峰[1] Yah Xiong-Wei;Wang Zhen-Guo;Jiang Xin-Ying;Zheng Jian-Gang;Li Min;Jing Yu-Feng(Research Center of Laser Phsion,China Academy of Engineering Physics,Mianyang 621900,China）2）（Collaborative Innovation Center of II;＇SA,Mianyang 621900,China)

机构地区：[1]中国工程物理研究院激光聚变研究中心,绵阳621900 [2]IFSA协同创新中心,绵阳621900

出　　处：《物理学报》2018年第18期98-106,共9页Acta Physica Sinica

基　　金：中国工程物理研究院高能激光科学与技术重点实验室(批准号：HEL2017-05-2)资助的课题

摘　　要：为了提升高功率固体激光器中激光二极管(LD)面阵抽运场性能,采用几何光学和数理统计分析的方法,建立了基于微透镜阵列匀束的LD面阵抽运耦合系统的数学与物理模型,对微透镜阵列参数与最终耦合输出抽运场参数之间的关系进行分析,明确了微透镜单元F数、微透镜通光单元数以及微透镜阵列空间周期参数的设计原则.经实验测试,优化设计完成的LD面阵抽运耦合系统光场不均匀度为7.9%,耦合效率为90.7%.In order to improve the performance of laser diode（LD） array pumping field in high-power solid state laser, an LD array pumping coupling system based on microlens array is used to achieve a high-uniformity pumping source with a longer transmission distance.The homogenizer has two structures based on microlens array, which are called diffracting homogenizer and imaging homogenizer. In this paper, we mainly study imaging microlens array due to its advantages of simple structure, better output homogeneity, flexibility of changing pumping field size, and insensitive to change in the input beam.First, the mathematical expression of the intensity distribution of target surface is derived based on the theory of geometrical optical. According to the geometrical optical formula, we obtain the relationship between the intensity distribution of target surface and system parameters, i.e., maximum incident angle of LD array, the distance between two microlens arrays, and the aperture and focal length of microlens. The boundary condition of microlens Fresnel number is derived based on the LD array beam parameters.Second, the influence of the number of microlens array elements on the output field homogeneity is studied theoretically by the mathematical statistics method. As the input beam is considered to be divided randomly, the central limit theorem is employed to derive the mathematical expression of calculating the integrated output field non-homogeneity.The formula shows that the non-homogeneity is in inverse proportion to the root of the number of microlens array elements and the related maximum and minimum value of input field intensity distribution. And the spatial period of microlens array is designed to be unrelated to the spatial period of LD array to reduce the coherence of LD beam.According to the luminescence field parameters of an LD array consisting of 25 bars, an LD coupling imaging microlens array homogenizer test system is designed and constructed based on the theoretical analysis above. Another contrast

关 键 词：微透镜阵列 抽运耦合 几何光学 数理统计 

分 类 号：TN248[电子电信—物理电子学]