基于自研器件的全光纤激光振荡器突破万瓦级  

All-Fiber Laser Oscillator Based on Home-Made Devices Surpassing 10 kW Level

作　　者：饶斌裕 李昊[1,2] 杨保来 叶新宇 路欣达 唐衡宇 王蒙 赵蓉 李智贤 陈子伦 潘志勇 肖虎 刘伟[1,2] 奚小明 史尘 王小林[1,2] 马鹏飞 王泽锋 陈金宝[1,2] Rao Binyu;Li Hao;Yang Baolai;Ye Xinyu;Lu Xingda;Tang Hengyu;Wang Meng;Zhao Rong;Li Zhixian;Chen Zilun;Pan Zhiyong;Xiao Hu;Liu Wei;Xi Xiaoming;Shi Chen;Wang Xiaolin;Ma Pengfei;Wang Zefeng;Chen Jinbao(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)

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

出　　处：《中国激光》2024年第19期293-295,共3页Chinese Journal of Lasers

基　　金：国家自然科学基金(11974427,12004431,62005315);湖南省科技创新计划(2021RC4027)。

摘　　要：高功率全光纤激光振荡器具有结构紧凑、控制逻辑简单、抗回光能力强等众多优势,在工业加工等领域中有着广泛的应用。近期,国防科技大学在全光纤激光振荡器研究方面取得突破,基于全自研光纤器件,首次实现万瓦级高光束质量激光输出。该全光纤激光振荡器采用自研的大模场面积掺镱光纤与匹配光纤光栅构成谐振腔,采用高功率半导体激光器(LD)直接泵浦,实现了光纤振荡器最高10.07 kW的激光输出,光光转化效率为~72%,输出激光中心波长为~1080 nm。最高功率时,输出光谱3 dB带宽为~6.6 nm,光谱中的拉曼抑制比为~16 dB,且激光器时序稳定,未发现模式不稳定效应。研究结果有望进一步推动高功率光纤激光器的发展及应用。Objective The primary objective of this study is to develop a high-power,all-fiber oscillator than can deliver exceptional output power and beam quality,which is crucial for advanced applications in material processing,laser manufacturing,and defense technology.The oscillator is intended to address the sustained demand for more robust and simpler laser systems that can operate at higher power levels without compromising stability and reliability.Nonlinear effects(NLEs)and transverse-mode instability(TMI)in fiber lasers,which are significant barriers to achieving high-power,high-beam-quality laser outputs,are addressed in this study.Methods In this study,a simple design of an all-fiber oscillator[Fig.1(a)]using 30μm/600μm large-mode-area(LMA)ytterbiumdoped fibers and matched fiber gratings inscribed by femtosecond laser phase-mask techniques is employed to form a resonant cavity.The system utilizes a low numerical aperture fiber to increase the loss of higher-order modes via a dual-wavelength pump source(969 nm and 982 nm)to reduce the thermal load and increase the gain saturation.TMI and NLEs are suppressed by appropriately designing the fiber grating bandwidth and optimizing the fiber coiling to ensure that multiple modes resonate adequately within the cavity while minimizing the intermodal coupling.Additionally,the angled cutting of the pigtail of a cladding light stripper can prevent backward Raman light from oscillating within the cavity.Results and Discussions The oscillator achieves an unprecedented output power of 10.07 kW.The system demonstrates a slope efficiency of 72.3%and an optical-to-optical efficiency of approximately 72%[Fig.1(b)].The laser output spectrum features a 3-dB bandwidth of approximately 6.6 nm,with a Raman suppression ratio of approximately 16 dB[Fig.1(c)].Notably,the laser maintains a stable operation with no significant TMI in the frequency domain[Fig.1(e)].However,the beam quality degrades slightly with increasing power[Fig.1(f)].This is attributed to the increasing contribution o

关 键 词：光纤振荡器 光纤光栅 受激拉曼散射 模式不稳定 

分 类 号：O436[机械工程—光学工程]