内通道多场耦合作用下旋转光束的传输特性研究  

Propagation Characteristics of Rotating Beam Under Multifield Coupling in Inner Channel

作　　者：杨文柏 熊皓 于虹 钟哲强[1] 张彬[1] Yang Wenbai;Xiong Hao;Yu Hong;Zhong Zheqiang;Zhang Bin(College of Electronics and Information Engineering,Sichuan University,Chengdu 610064,Sichuan,China;China Space Sanjiang Group Co.,Ltd,Wuhan 430040,Hubei,China)

机构地区：[1]四川大学电子信息学院,四川成都610064 [2]中国航天三江集团有限公司,湖北武汉430040

出　　处：《中国激光》2024年第13期164-174,共11页Chinese Journal of Lasers

基　　金：国家自然科学基金(61905167)。

摘　　要：为缓解内通道激光传输过程中热效应引起的光束质量退化,通过建立内通道光-流-固多场耦合作用的物理模型,开展了内通道中旋转光束的传输特性研究。在此基础上,揭示了旋转光束缓解内通道热效应的物理机制,分析了拓扑荷数、旋转速率、气体吸收系数等关键参数对输出光束质量的影响。结果表明,旋转光束能有效抑制内通道中的激光传输热效应,改善输出激光的光束质量。通过增加光束旋转速率、拓扑荷数,以及减小气体的吸收系数,可以有效提升旋转光束对内通道热效应的抑制效果。Objective The absorption of laser energy by gases and optical components in inner channels of high-power laser systems leads to complex interactions among laser, fluid, and solids. This interaction causes uneven optical path differences as laser beams propagate,significantly degrading beam quality. As laser power continuously increases, this degradation, driven by thermal effects in the inner channel, becomes more severe. Understanding the mechanism of thermal effect and developing strategies to reduce beam quality degradation are essential. However, most existing studies on mitigating the thermal effect of the inner channel focus primarily on the laser-fluid interaction, often overlooking the optical-structure interaction. In this study, a physical model of the multi-field coupling interaction of the laser-fluid-solid in the inner channel is established to reveal the propagation characteristics of a rotating beam in the inner channel and mitigation methods are proposed for the degradation of beam quality caused by the thermal effect.Methods In this study, a physical model is established to investigate the propagation characteristics of a rotating beam in an inner channel, considering the laser-fluid-solid multifield coupling effect. To achieve this, a split-step Fourier algorithm is used to simulate the optical field in the inner channel at each time step. The resulting heat source distributions of the optical elements and fluid are then integrated into the calculations of the flow field and solid mechanics using the finite-element-method(FEM) method. By employing ray tracing and power spectrum inversion method, the aberrations due to the nonuniform distribution of temperature and velocity within the fluid, as well as the deformation distribution of the solid, can be accurately calculated. These results are subsequently incorporated into the analysis of the laser propagation, enabling the calculation and analysis of the propagation characteristics of the rotating beam within the inner channel.In the subsequent t

关 键 词：光通信 内通道 热效应 光束质量 旋转光束 多场耦合 

分 类 号：O436[机械工程—光学工程]