双端泵浦5 kW环形光束光纤激光振荡器  

5-kW Monolithic Fibre Laser Oscillator with Ring Beam Output Employing Bidirectional-Pumping Scheme

作　　者：王鹏[1,2,3,4] 杨保来 张汉伟[1,2,3] 奚小明 史尘[1,2,3] 王小林 许晓军 吕品 Wang Peng;Yang Baolai;Zhang Hanwei;Xi Xiaoming;Shi Chen;Wang Xiaolin;Xu Xiaojun;Lii Pin(College of Advanced Interdisciplinary Studies,National University of Defense Technology,Ch angsha,Hunan 410073,China;State Key Laboratory of Pulsed Laser Technology,Changsha,Hunan 410073,China;Hunan Provincial Key Laboratory of High Energy Laser Technology,Changsha,Hunan 410073,China;Institute of Automation,Chinese Academy of Sciences,Beijing 100190,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 [4]中国科学院自动化研究所,北京100190

出　　处：《光学学报》2022年第5期152-161,共10页Acta Optica Sinica

基　　金：国家自然科学基金(62005315);长沙市杰出创新青年培养计划(kq2009004)。

摘　　要：基于双端泵浦结构搭建了光纤激光振荡器,采用25/400μm(纤芯直径为25μm,包层直径为400μm)大模场双包层掺镱光纤作为增益介质,采用波长为915 nm的半导体激光器作为泵浦源。通过光纤选型、合理配比前后向泵浦功率及模式控制,实现了对光纤受激拉曼效应及动态模式不稳定效应的抑制。该光纤激光振荡器在泵浦功率为7.5 kW下的最大输出功率达到5.08 kW,光光转换效率为68%,受激拉曼抑制比为37 dB,其时域特性稳定,没有出现动态模式不稳定现象。最大输出功率下,出射激光在X方向和Y方向的光束质量(M;)测量结果分别为2.483和2.514,远场光斑形态为环形,环状区域与中心区域的光强之比为1.6。在最大输出功率下该光纤激光振荡器连续工作1 h无异常,各部位光纤器件的温度均处于可接受范围。A fibre laser oscillator is constructed using the bidirectional-pumping structure and a 25/400 μm(the core diameter is 25 μm and the cladding diameter is 400 μm). The gain medium is a large-mode-area double-cladding ytterbium-doped fibre, and a 915-nm semiconductor laser is utilised as the pump source. The suppression of fibre-stimulated Raman scattering and dynamic mode instability is accomplished via fibre selection, an appropriate ratio of forwarding and backward pump power and mode control. The fibre laser oscillator produced a maximum output power of 5.08 kW at a pump power of 7.5 kW, with a light-light conversion efficiency of 68%, and the suppression ratio of stimulated Raman scattering is 37 dB. The time-domain properties remained constant, with no evidence of dynamic mode instability. The beam quality measurement results of output laser in the X and Y directions at maximum power are 2.483 and 2.514, respectively. The far-field light spot had a ring shape, and the light intensity ratio between the ring area and the central area is 1.6. The fibre laser oscillator worked continuously for 1 h at maximum output power without any abnormality, and the temperature of the fibre optic components in all parts is within the acceptable range.

关 键 词：激光器 掺镱光纤 光纤激光振荡器 环形光束 

分 类 号：O436[机械工程—光学工程]