变纤芯直径掺镱光纤激光器:现状与趋势  

Ytterbium-Doped Core-Diameter-Variable Fiber Laser: Current Situation and Develop Tendency

作　　者：王小林[1,2,3] 文榆钧 张汉伟 奚小明[1,2,3] 史尘 杨保来 王鹏 潘志勇 王泽锋[1,2,3] 许晓军 陈金宝 Wang Xiaolin;Wen Yujun;Zhang Hanwei;Xi Xiaoming;Shi Chen;Yang Baolai;Wang Peng;Pan Zhiyong;Wang Zefeng;Xu Xiaojun;Chen Jinbao(College of Advanced Interdisciplinary Studies,National University of Defense Technology,Changsha 410073,HuNan,China;State Key Laboratory of Pulsed Powver Laser Technology,Changsha 410073.HuNan,China;Hunan Procincial 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]脉冲功率激光技术国家重点实验室,湖南长沙410073 [3]高能激光技术湖南省重点实验室,湖南长沙410073

出　　处：《中国激光》2022年第21期1-29,共29页Chinese Journal of Lasers

基　　金：长沙市杰出创新青年培养计划(kq2106008);国家自然科学基金(61735007)。

摘　　要：为了抑制高功率光纤激光器中的非线性效应,纤芯直径沿着长度方向变化的增益光纤(简称变纤芯直径增益光纤)常被作为激光器的增益介质。变纤芯直径增益光纤主要包括单锥形光纤、纺锤形光纤和马鞍形光纤等,该类光纤同时具有光束质量保持和模式不稳定效应抑制的能力,在高功率光纤激光器中有着广泛的应用前景。近年来,利用单锥形光纤已经实现了峰值功率为97 MW的飞秒脉冲激光,利用纺锤形光纤已经实现了功率为5 kW的连续激光。介绍了变纤芯直径增益光纤的优点和制作方法,对变纤芯掺镱单频/窄线宽光纤激光器、脉冲光纤激光器和高功率连续宽谱光纤激光器的发展现状进行了详细介绍,分析了变纤芯直径掺镱光纤激光器的发展趋势及其支撑万瓦级高功率连续激光输出的可行性。研究结果为高功率光纤激光器的发展提供了参考。Significance In the power scaling process of fiber lasers, nonlinear effects are one of the most important limiting factors. In order to suppress the nonlinear effects in high power fiber lasers, researchers have proposed to use a gain fiber whose core diameter is variable along the length direction(called core-diameter-variable gain fiber) as the laser gain medium. Core-diameter-variable gain fibers mainly includes single-tapered fibers, spindle-shaped fibers, and saddleshaped fibers. Core-diameter-variable gain fibers have many advantages over the ordinary gain fibers. This type of fiber used in lasers can make the laser have the capabilities of maintaining beam quality, suppressing mode instability, and mitigating amplified spontaneous emission(ASE) simultaneously, and has a broad application prospect in the field of high power lasers. In particular, the spindle-shaped gain fiber with an asymmetric structure may become the key device that breaks through the power limitation of the traditional gain fibers with uniform core diameters and obtains a high power laser output.Progress Core-diameter-variable gain fibers can effectively suppress nonlinear effects and maintain good beam quality, and have been widely used in single-frequency and narrow-linewidth amplifiers. Commercial polarization-maintaining tapered ytterbium-doped fibers are used in single-frequency fiber lasers with an output power of 550 W. They are also used in pulsed fiber lasers to break through the peak power output. Since 2014, the lasers based on this type of fiber have been extensively studied, and the power has been rapidly increased while maintaining the beam quality. In 2017, a femtosecond pulsed laser with an output peak power of 22 MW was realized based on the ytterbium-doped tapered fiber combined with the pulse compression technology. In 2021, the peak was increased to 97 MW with the diffraction limit beam quality in a femtosecond pulsed laser system using an ytterbium-doped tapered fiber. After the non-polarizationmaintaining fiber tec

关 键 词：激光器 光纤激光器 变纤芯直径光纤 非线性效应 模式不稳定效应 

分 类 号：O436[机械工程—光学工程]