Gu Yanran, Lei Chengmin, Yang Huan, Xiao Hu, Leng Jinyong, Chen Zilun
Appl Opt. 2019 Feb 20;58(6):1336-1340. doi: 10.1364/AO.58.001336.
We investigate a high-beam-quality (6+1)×1 signal and pump combiner with 50 μm core diameter of the output fiber based on the tapered-fused fiber bundle technique for the first time. The influence of taper ratio of the taper bundle for different mode proportions of the output fiber and the transition efficiency of the signal light are analyzed numerically. In the experiment, a signal fiber core diameter matching from 10 to 50 μm in the combiner is achieved. We experimentally demonstrate that the total 1018 nm pump efficiency of the combiner is >98% and the signal light insertion loss is less than 2%, with a beam quality factor M of 1.59. Also, we have set up an amplifier based on the combiner, whose output laser power can achieve 2340 W with the slope efficiency of 73.76%. The beam quality factor M of the output laser is 2.83 at the maximum power output, and a high beam quality is maintained when a large-mode-area fiber is employed in the laser system.
我们首次基于锥形熔接光纤束技术研究了一种输出光纤芯径为50μm的高光束质量(6 + 1)×1信号与泵浦合束器。数值分析了锥形束的锥比对于输出光纤不同模式比例以及信号光转换效率的影响。在实验中，实现了合束器中信号光纤芯径从10μm到50μm的匹配。我们通过实验证明，合束器的1018nm泵浦总效率>98%，信号光插入损耗小于2%，光束质量因子M为1.59。此外，我们基于该合束器搭建了一个放大器，其输出激光功率可达2340W，斜率效率为73.76%。在最大功率输出时，输出激光的光束质量因子M为2.83，当激光系统中采用大模面积光纤时可保持高光束质量。
