基于单级MOPA结构实现6 kW全光纤窄谱激光输出  

Record High-Power Narrow-Linewidth Fiber Laser Based on One-Stage Master Oscillator Power Amplification Configuration

作　　者：奚小明 王蒙 田鑫 赵晓帆 饶斌裕 王鹏[1,2,3] 杨保来 张汉伟 王小林[1,2,3] 王泽锋 陈金宝[1,2,3] Xi Xiaoming;Wang Meng;Tian Xin;Zhao Xiaofan;Rao Binyu;Wang Peng;Yang Baolai;Zhang Hanwei;Wang Xiaolin;Wang Zefeng;Chen Jinbao(College of Advanced Interdisciplinary Studies,National University of Defense Technology,Changsha 410073,Hunan,China;State Key Laboratory of Pulsed Power Laser 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]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11期216-219,共4页Chinese Journal of Lasers

基　　金：国家自然科学基金面上项目(11974427,12004431);湖南省自然科学基金杰出青年科学基金(2019JJ20023);湖南省科技创新人才计划科技创新领军人才项目(2021RC4027);脉冲功率激光技术国家重点实验室主任基金(SKL2020ZR05,SKL2021ZR01)。

摘　　要：高功率窄线宽光纤激光器在非线性频率转换、光谱合成以及相干合成等领域具有广阔的应用前景。本文将自研的窄线宽振荡器作为种子,采用单级主振荡功率放大(MOPA)技术,实现了6.02 kW窄谱激光输出。在最高功率时,信号光的中心波长为1079.26 nm,3 dB带宽约为0.36 nm,10 dB带宽约为1.47 nm,放大级对应的光-光转换效率约为85.7%,光束质量M约为2.7。据查,这是目前公开报道的窄线宽光纤激光器的单纤最高输出功率。本研究对于高功率窄线宽光纤激光的发展和研究具有重要的指导意义。Objective The power scaling of high-power narrow-linewidth fiber lasers has recently received a lot of attention.It is challenging for power scaling in a narrow-linewidth fiber laser since thresholds of nonlinear effects,such as self-phase modulation(SPM),stimulated Raman scattering(SRS),stimulated Brillouin scattering(SBS)and transverse mode instability(TMI),are much lower than those in a conventional fiber laser.A narrow-linewidth seed could be boosted using a master oscillator power amplification(MOPA).Two promising seed sources,i.e.,phase-modulated single-frequency laser and fiber Bragg grating-based oscillator,are used in the narrow linewidth MOPA,and 3 kW and 5 kW level narrow-linewidth fiber lasers have been reported experimentally based on them,respectively.MOPAs based on the first type of seeds exhibit relatively weaker nonlinear effects and induce smaller spectrum broadening.However,the multistage configuration limits their applications.MOPAs based on the second kind of seeds(i.e.,one-stage MOPA)possess a simple and robust structure.Based on experimental and theoretical results,using one-stage MOPA is a promising method for producing high power narrow-linewidth fiber lasers.Methods The one-stage MOPA system comprises a narrow-linewidth fiber oscillator and bidirectional pumped amplifier.A pair of homemade fiber Bragg gratings(FBGs)and a piece of Yb-doped fiber(YDF)with a core/cladding diameter of 10/130μm were used to establish the seeds.High reflector(HR)and the output coupler(OC)FBGs are 1.0and 0.06nm,respectively.The measured 3dB bandwidth of the seed is~0.05nm at the output power of 20 W.A large-mode-area(LMA)YDF with a mode-filed area of~420μm^(2) was used in the amplifier.The seed laser was coupled into the amplifier using a mode-field adapter(MFA)to mitigate the mode-filed mismatching between them.Groups of wavelength-optimized LDs were spliced with the forward and backward combiners and used as pump sources.The unabsorbed cladding light was stripped off using a cladding light stripper.Then the

关 键 词：激光器 高功率 窄线宽 主振荡功率放大 

分 类 号：O436[机械工程—光学工程]