高功率激光合束器工作可靠性能评估方法研究  

Research on evaluation method of high power laser beam combiner working reliability

作　　者：田晓 李奔[2] 白杨 康宇栋[1] 胡子豪 Tian Xiao;Li Ben;Bai Yang;Kang Yudong;Hu Zihao(School of Science,Xi'an Aeronautical Institute,Xi'an 710077,China;Institute of Photonics&Photon-Technology,Northwest University,Xi'an 710127,China)

机构地区：[1]西安航空学院理学院,陕西西安710077 [2]西北大学光子学与光子技术研究所,陕西西安710127

出　　处：《仪器仪表学报》2022年第9期106-114,共9页Chinese Journal of Scientific Instrument

基　　金：陕西省教育厅服务地方专项计划项目(19JC040);陕西省省重点研发计划项目(2020GY-118);国家重点研发计划项目(2017YFB0405102)资助。

摘　　要：为降低高功率激光在单根光纤中的传输风险,提出基于多光纤传输的激光非相干空间合束19×1圆斑合束器。基于“内外同心圆+中心”同轴排列方式,采用光线追迹法进行合束器的光学设计,同时为实现合束器长期运行可靠性评估,基于多激光束同步照射光学元件的体吸收模型,采用有限元方法对合束器内部透镜的温度、热畸变和热应力等进行研究。结果表明,在10 kW激光照射30 mins下,合束器内部透镜的最高温度为381.11 K,远低于熔融石英1900 K的软化点温度,热畸变相关的最大光圈数为0.07,远小于1个光圈数的透镜加工公差,热应力最大值为14.02 MPa,小于熔融石英4.5 GPa的屈服应力。此外实验测得合束器输出总功率可达10.43 kW。本研究对评价其他高功率激光系统的长期运行可靠性提供了有效的方法参考。To reduce the transmission risk of high-power laser in a single fiber,a 19×1 incoherent space laser beam combiner with circular spot based on multiple optical fiber transmission was presented.The coaxial close arrangement based on“inner and outer concentric circles+center”is applied in the optical design of the combiner,and the lenses parameters of the combiner are obtained by ray tracing method.Simultaneously,to evaluate the long-term operation reliability of the 19×1 laser beam combiner accurately,the coupled thermo-mechanical characteristics of all optics in the beam combiner is analyzed,to clarify the distributions and evolution laws of temperature field and thermal stress field of optics by using the finite element method(FEM).The multi-beam laser volumetric heat source model is established based on the overall heat source distribution of 19 laser beams synchronously transmitted optical lenses.Then,the temperature field,thermal displacement and stress of optics are simulated.Results show under the irradiation of 10 kW laser for 30 minutes,the temperature of all optical lenses in the beam combiner with the maximum of 381.11 K is far lower than the softening temperature of 1900 K of the fused silica material.The thermal deformation with the maximum corresponding aperture number of 0.07 is within the design tolerance,and stress with the maximum of 14.02 MPa is less than the yield stress of 4.5 GPa of the fused silica.In addition,the total laser power output by the beam combiner can reach 10.43 kW.The study provides an effective method reference for evaluating the long-term operation reliability of other high-power laser source.

关 键 词：高功率激光 激光合束器 多激光束体热源 有限元分析 热力学特性 

分 类 号：TH744[机械工程—光学工程] TN248[机械工程—仪器科学与技术]