半导体侧面抽运板条激光器光束质量优化  

Beam quality optimization of semiconductor side-pumped slab lasers

作　　者：熊新健 陈培锋[1] 王英[1] 杨亚楠 李响 XIONG Xinjian;CHEN Peifeng;WANG Ying;YANG Ya’nan;LI Xiang(School of Optical and Electronic Information,Huazhong University of Science and Technology,Wuhan 430074,China)

机构地区：[1]华中科技大学光学与电子信息学院

出　　处：《激光技术》2019年第5期724-728,共5页Laser Technology

摘　　要：为了优化高功率板条激光器的光束质量,采用提高单侧基模光束的尺寸来限制腔内部分高阶模式振荡的方法,针对半导体侧面抽运板条激光器,测量了激光器在抽运状态下水平和竖直方向热焦距,建立了热透镜等效模型,并以平-平腔为参考,设计了水平和竖直方向单侧基模尺寸均会扩大的平-凹腔。验证了对于激光介质截面尺寸固定的板条激光器,扩大单侧基模尺寸可以限制高阶模式从而优化光束质量,并提出了进一步优化板条激光器性能的研究方法。结果表明,当平-凹腔的腔长为370mm时,输出功率为59.9W,水平方向M 2因子由平-平腔的115.6显著优化至32.9,竖直方向M 2因子由116.4显著优化为60.9。该研究对于板条激光器获得高质量输出及相关应用有实际意义。In order to optimize beam quality of high power slab lasers, the oscillation of some high-order modes in the cavity was limited by increasing the size of unilateral fundamental mode beam. For semiconductor side-pumped slab lasers, horizontal and vertical thermal focal lengths of the laser under pumping were measured. The equivalent model of thermal lens was established. By using flat-flat cavity as reference, a flat-concave cavity with enlarged dimension of unilateral fundamental modes in both horizontal and vertical directions was designed. It was verified that, for slab lasers with fixed cross-section size of laser medium, expanding the size of one-sided fundamental mode can limit the higher-order mode and optimize the beam quality. A method for further optimizing the performance of slab lasers was proposed. The results show that, when the length of flat-concave cavity is 370mm and the output power is 59.9W, horizontal M 2 factor is significantly optimized from 115.6 for flat-flat cavity to 32.9 and vertical M 2 factor is significantly optimized from 116.4 to 60.9. This research has practical significance for obtaining high quality output of slab lasers and the related application.

关 键 词：激光器 半导体侧面抽运 谐振腔 热焦距 基模 光束质量 

分 类 号：TN242[电子电信—物理电子学] TN243