高功率光纤激光器纤芯温度在线测量技术及其应用研究进展  

Real-Time Temperature Measurement of High-Power Fiber Laser Core and Its Applications

作　　者：周子超 崔文达 奚小明 韩凯 杨剑[2] 许晓军[1,3,4] Zhou Zichao;Cui Wenda;Xi Xiaoming;Han Kai;Yang Jian;Xu Xiaojun(College of Advanced Interdisciplinary Studies,National University of Defense Technology,Changsha 410073,Hunan,China;College of Information and Communication,National University of Defense Technology,Wuhan 430034,Hubei,China;Nanhu Laser Laboratory,National University of Defense Technology,Changsha 410073,Hunan,China;Hunan Provincial Key Laboratory of High Energy Laser Technology,Changsha 410073,Hunan,China)

机构地区：[1]国防科技大学前沿交叉学科学院,湖南长沙410073 [2]国防科技大学信息通信学院,湖北武汉430034 [3]国防科技大学南湖之光实验室,湖南长沙410073 [4]高能激光技术湖南省重点实验室,湖南长沙410073

出　　处：《光学学报》2023年第17期161-171,共11页Acta Optica Sinica

摘　　要：高功率光纤激光器中的热效应是影响激光器稳定运行的重要因素。为了增加高功率光纤激光器的稳定性,对高功率光纤激光器的纤芯温度进行测量至关重要。本文首先介绍了利用光纤光栅与光频域反射技术测量增益光纤纤芯温度的方法,分析了不同光纤激光器与放大器纤芯温度分布的测量结果。而后介绍了纤芯温度分布式在线测量方法在高功率光纤激光器热效应与非线性效应调控等方面的应用,为高功率光纤激光器性能提升研究提供了参考。Significance In the past few years,high-power lasers have shown great potential in the application of industrial processing,medical treatment,national defense,and other fields.Fiber lasers have become a mainstream technical solution to high-power lasers due to their unique advantages of excellent output beam quality,high energy conversion efficiency,good heat dissipation capacity,compact structure,and high robustness.Currently,a single fiber laser can reach the output power of 10 kW.However,due to energy loss,quantum defect,and other factors,the waste heat generated in high-power fiber lasers has seriously restricted the further improvement of laser output power.The performance of the high-power fiber laser is significantly affected by the high temperature inside the gain fiber,which reduces the stability of the fiber laser,and results in mode instability effect and degradation of the output beam quality.Theoretical studies have shown that the mode instability effect is accompanied by dynamic gratings caused by the thermo-optical effect in the fiber core.The high-order mode and fundamental mode are coupled with each other under the interaction of dynamic gratings,causing degraded output beam quality and further restricting the power improvement of high-power fiber lasers.Therefore,the thermal effect in high-power fiber lasers is an important factor that determines laser operation stability.It is very important to measure and monitor the temperature of the fiber core in the laser for improving the stability of the highpower fiber laser and avoid the thermal damage of the gain fiber.Progress The refractive index of the fiber core is affected by the temperature of the fiber material to change the phase or spectrum of the reflected/scattered light.By measuring the phase or spectrum change of the reflected/scattered light in the optical fiber,the temperature change in the optical fiber core can be detected.Fiber Bragg grating(FBG)is a reflector composed of short fiber with refractive index period modulation,and it can

关 键 词：高功率光纤激光器 纤芯温度测量 光纤传感 光频域反射技术 

分 类 号：O437[机械工程—光学工程]