高功率光纤激光器中反向抽运结构对模式不稳定的抑制  

Mode Instability Mitigation by Counter-Pumped Scheme in High Power Fiber Laser

作　　者：李泽标 郭超[1] 赵鹏飞[1] 黄志华[1] 向小雨[1] 梁小宝[1] 李成钰[1] 林宏奂[1] 王建军[1] 景峰[1] 徐善辉[2] 杨中民[2] 

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 [2]华南理工大学光通信材料研究所,广东广州510640

出　　处：《中国激光》2017年第8期72-76,共5页Chinese Journal of Lasers

基　　金：国家自然科学基金(11404305;11474257;11674103;61635004;61535014;51132004;51302086);国家重点研究和发展项目(2016YFB0402204);国家杰出青年科学基金(61325024)

摘　　要：模式不稳定效应会影响高功率激光输出的光束质量,成为高功率光纤激光器定标放大过程中获得近衍射极限光斑的主要限制因素。基于模式耦合理论建立描述模式不稳定现象的半解析模型。理论模型的计算结果表明与正向抽运结构相比,反向抽运和双向抽运结构具有更高的模式不稳定阈值。通过实验对理论结果进行验证,发现反向抽运光纤激光器的模式不稳定阈值至少比正向抽运结构高50%。实验中搭建反向抽运光纤激光器,实现了2kW窄线宽高光束质量激光输出。Mode instability has become the major limitation for power scaling of fiber lasers with nearly diffraction- limited beam quality. Based on mode coupling theory, we establish a semi-analytical model to simulate mode instability effect. Compared with co-pumped fiber laser, counter-pumped and bi-pumped fiber lasers reveal mode instability threshold enhancement in our theoretical model. Compared with that of the co-pumped scheme, the experimental mode instability threshold of the counter-pumped fiber laser is enhanced by at least 50G. Moreover, we demonstrate a kW high power narrow-linewidth counter-pumped fiber laser with high beam quality.

关 键 词：激光器 模式不稳定性 光纤放大器和振荡器 热效应 耦合模理论 

分 类 号：TN243[电子电信—物理电子学]