自研20μm/400μm掺镱光纤实现4 kW高品质激光输出  

4 kW High-Beam-Quality Laser Output Using Homemade 20μm/400μm Yb-Doped Fiber

作　　者：李芳[1] 张春 代江云 沈昌乐[1] 刘念[1] 陈艺 姜蕾[1] 张立华 吕嘉坤 舒强 廖若宇 周宏冰 高聪[1] 林宏奂[1] 赵龙彪[1] 王建军[1] 景峰[1] Li Fang;Zhang Chun;Dai Jiangyun;Shen Changle;Liu Nian;Chen Yi;Jiang Lei;Zhang Lihua;LüJiakun;Shu Qiang;Liao Ruoyu;Zhou Hongbing;Gao Cong;Lin Honghuan;Zhao Longbiao;Wang Jianjun;Jing Feng(Laser Fusion Research Center,China Academy of Engineering Physics(CAEP),Mianyang 621900,Sichuan,China)

机构地区：[1]中国工程物理研究院激光聚变研究中心,四川绵阳621900

出　　处：《中国激光》2023年第5期205-208,共4页Chinese Journal of Lasers

摘　　要：基于自主研制的20μm/400μm掺镱双包层光纤,搭建了主振荡功率放大器,开展了高功率光纤激光实验,实现了中心波长为1064 nm、最高功率为4 kW、斜率效率为81%、光束质量因子(M^(2))为1.39、拉曼抑制比大于30 dB的激光输出。据我们所知,该结果是已公开报道的基于国产20μm/400μm掺镱双包层光纤实现的最高品质激光输出。Objective Fiber lasers are widely used in industry,national defense,and military fields owing to their advantages of high electrooptical efficiency,compact structure,and excellent stability,and Ybdoped fiber(YDF)lasers are a crucial fiber laser direction.Compared with 25μm/400μm fiber,20μm/400μm YDF is less expensive and exhibits easier modecontrolling.Hence,20μm/400μm YDF lasers have been widely applied and developed rapidly.Here,we successfully prepare highquality 20μm/400μm YDF by improving the YDF preform fabrication technique.A master oscillator power amplifier(MOPA)system with the domestic 20μm/400μm doubleclad YDF realizes the highest output laser power of 4 kW without the transverse mode instability(TMI)by adopting the backward pumping method.Methods Using a homemade 20μm/400μm doubleclad YDF,we construct a MOPA system to test the property of the fiber at high power.The seed has a center wavelength of 1064 nm and output power of 19 W.A mode field adapter with a 10μm/130μm input fiber and 20μm/400μm output fiber is adopted to connect the seed and the chirped and tilted fiber Bragg grating which is utilized to suppress the stimulated Raman scattering(SRS)signal.We adopt a cladding power stripper(CPS)before the main amplifier to discard the residual pump power from the backward pump sources.The active fiber of the amplifier is a 15-mlong 20μm/400μm YDF and coiled with a 9-cm diameter to suppress the TMI effect.The pump sources comprising five 976-nmLD pump modules are injected into the 20μm/400μm YDF using a(6+1)×1 signalpump combiner with a 25μm/400μm signal fiber.The maximum output power of each pump module is 1030 W.A CPS is utilized before the quartz block holder to discard the highermode in laser signal.After passing through the system,the output power of the seed decreases to 8 W.The beam quality of the output laser is measured at different output powers,and the TMI effect is assessed according to timefrequency characteristics.The continuous laser output power at the 4-kW level i

关 键 词：激光器 光纤激光器 高功率 掺镱光纤 双包层光纤 

分 类 号：O436[机械工程—光学工程]