6kW超荧光光纤光源  

6 kW Superfluorescent Fiber Light Source

作　　者：李瑞显 王崇伟 叶俊 肖虎 许将明 冷进勇 周朴[1] Li Ruixian;Wang Chongwei;Ye Jun;Xiao Hu;Xu jiangming;Leng Jinyong;Zhou Pu(College of Advanced Interdisciplinary Studies,National University of Defense Technology,Changsha 410073,Hunan,China;Nanhu Laser Laboratory,National University of Defense Technology,Changsha 410073,Hunan,China;Hunan Provincial Key Laboratory of High Energy Laser Technology,National University of Defense 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]国防科技大学南湖之光实验室,湖南长沙410073 [3]国防科技大学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》2023年第22期204-206,共3页Chinese Journal of Lasers

基　　金：国家自然科学基金(62035015);湖南省创新研究群体(2019JJ1005)。

摘　　要：由于自激振荡的限制,单级超荧光光纤光源的功率提升十分困难,目前仅达到百瓦量级。基于主振荡功率放大(MOPA)方案,使用1018 nm光纤激光级联泵浦1080 nm波段的超荧光,实现了6.2 kW高功率输出。最高功率下的光光转换效率为81.5%,没有出现横模不稳定(TMI),功率提升受限于受激拉曼散射(SRS)。Objective High-power superfluorescent fiber light sources have a wide range of applications,including Raman fiber laser pumping,optical coherence imaging,and spectral beam combining.They are favored for their simple structure,low temporal coherence,high temporal stability,absence of relaxation oscillation,and lack of self-locking mode pulses.However,because of the limitation of parasitic lasing,it is challenging to increase the power of a single-stage superfluorescent fiber light source.Currently,its power only reaches a few hundred watts.A master oscillator power amplification(MOPA)structure provides a solution to achieve high power output by amplifying a low-power superfluorescent seed.The highest reported power of 1-μm superfluorescence based on a Yb-doped fiber MOPA structure is 3 kW.Further power scaling is limited by stimulated Raman scattering(SRS)and transverse mode instability(TMI).In this study,we implement backward cascaded pumping to suppress TMI and SRS and boost the superfluorescent output to more than 6 kW.Methods First,the superfluorescent source is filtered out by a bandpass filter and amplified to 40 W by two pre-amplifiers.In the seed stage,it is important to use isolators to reduce the negative impact of backscattering on the superfluorescent seed source.In the amplification stage,the superfluorescent light is launched into the double-clad ytterbium-doped fiber(YDF)through a mode field adapter,a cladding light stripper,and a combiner.A 1018-nm pump laser is injected into YDF through a backward combiner.Finally,the amplified superfluorescent light is emitted through a cladding light stripper and a beam collimator.Results and Discussions The output power increases almost linearly with the injected pump power.At a pump power of 7554 W,the output power reaches 6200 W with a corresponding optical-to-optical conversion efficiency of 81.5%.As the power increases,the spectral width gradually broadens,and the 3-dB linewidth increases from 2.08 nm at 40 W to 7.72 nm at 6200 W.At an output power of 6200

关 键 词：光纤光学 超荧光光源 高功率 级联泵浦 受激拉曼散射 横模不稳定 

分 类 号：TN248[电子电信—物理电子学]