封闭通道浮力对流下阵列光束热晕效应分析  

Thermal Blooming Effect of Array Beams Under Buoyancy Convection in Closed Channel

作　　者：刘万生 袁志军[1] 王汉斌 咸昱桥[1,2] 苏梦琪 何兵 周军[1] Liu Wansheng;Yuan Zhijun;Wang Hanbin;Xian Yuqiao;Su Mengqi;He Bing;Zhou Jun(Shanghai Key Laboratory of All Solid-State Laser and Applied Techniques,Shanghai Institute of Optics and Fine Mechanics,Chinese Academy of Sciences,Shanghai 201800,China;Center of Materials Science and Optoelectronics Engineering,University of Chinese Academy of Sciences,Beijing 100049,China;School of Physics,Harbin Institute of Technology,Harbin,Heilongjiang 150006,China)

机构地区：[1]中国科学院上海光学精密机械研究所上海市全固态激光器与应用技术重点实验室,上海201800 [2]中国科学院大学材料与光电研究中心,北京100049 [3]哈尔滨工业大学物理学院,黑龙江哈尔滨150006

出　　处：《光学学报》2022年第1期176-185,共10页Acta Optica Sinica

基　　金：国家重点研发计划(2018YFB0504500);上海市自然科学基金(19ZR1464000,19ZR1464200)。

摘　　要：研究了高功率激光在封闭通道传输时,空气吸收激光能量引发的浮力对流对热晕效应的影响。建立了浮力对流下热晕效应的物理模型,采用数值计算方法分析了热传导和对流传热这两种影响光束质量的因素,发现浮力对流对封闭通道内热晕效应有削弱作用,并且会造成光束质心漂移。研究了不同排布方式下阵列光束的远场光斑形状、光束质量和光斑质心漂移。结果表明,阵列光束间相互作用下的浮力对流更强,对热晕效应的削弱作用更强,不同排布方式下不同位置处光束的情况不同,通过选择合适的排布方式可以找到优化的光束质量和质心漂移。验证了利用轴向风可以抑制热晕效应的方法,结果表明浮力对流的存在会促进热晕效应的减弱,当轴向风逐渐增大时,热晕逐渐被抑制,浮力对流的影响逐渐消失。This paper studies the influence of buoyancy convection caused by the laser energy absorbed by air during the propagation of high-power laser in a closed channel on the thermal blooming effect. A physical model of the thermal blooming effect under buoyancy convection is constructed. Two factors that affect beam quality, namely heat conduction and convection heat transfer, are analyzed by a numerical calculation method. It is found that buoyancy convection can reduce the thermal blooming effect in the closed channel and cause beam centroid drift. The far-field spot shape, beam quality, and spot centroid drift of array beams with different arrangements are studied. The results show that the buoyancy convection under the interaction among the array beams is greater, and the reduction of the thermal blooming effect is more severe. The conditions of beams at different positions with different arrangements are different. Beam quality and centroid shift can be optimized by choosing the appropriate arrangement. In addation, we verified that axial wind can be adopted to suppress the thermal blooming effect. The results show that buoyancy convection can promote the reduction of the thermal blooming effect. When the axial wind increases, the thermal blooming effect vanishes, and the influence of buoyancy convection gradually disappears.

关 键 词：激光光学 激光传输 热晕 浮力对流 阵列光束 

分 类 号：TN012[电子电信—物理电子学]