Zhang Zhilun, Lin Xianfeng, Zhang Xu, Luo Yonghui, Liao Shibiao, Wang Xiaoliang, Chen Gui, Xing Yingbin, Li Haiqing, Peng Jinggang, Dai Nengli, Zhou Jun, Li Jinyan
Opt Express. 2022 Aug 29;30(18):32333-32346. doi: 10.1364/OE.466111.
A low-numerical aperture (NA) confined-doped long-tapered (LCT) Yb-doped fiber is proposed and fabricated by modified chemical vapor deposition combined with solution doping technique. The LCT fiber owns the core NA of ∼0.05 and the gain dopant doping diameter ratio of ∼77%, with a core/cladding diameter of 25/400 µm at both ends and 37.5/600 µm in the middle. The laser performance is demonstrated by a bidirectional pumping all-fiber amplifier, of which a 4.18-kW single-mode (M factor ∼1.3) laser output is achieved with a slope efficiency of ∼82.8%. Compared with the conventional fiber, the co-pumped and counter-pumped transverse mode instability thresholds and beam quality of the LCT fiber are remarkably enhanced. Throughout the continuous operation, the LCT fiber amplifier presents high power stability with fluctuation of < 1%. These results indicate that LCT fiber has great potential in power scaling remaining excellent beam quality.
通过改进的化学气相沉积结合溶液掺杂技术，提出并制备了一种低数值孔径（NA）的受限掺杂长锥形（LCT）掺镱光纤。该LCT光纤的纤芯NA约为0.05，增益掺杂剂掺杂直径比约为77%，两端的纤芯/包层直径为25/400 µm，中间为37.5/600 µm。通过双向泵浦全光纤放大器展示了其激光性能，实现了4.18 kW的单模（M因子约为1.3）激光输出，斜率效率约为82.8%。与传统光纤相比，LCT光纤的同向泵浦和反向泵浦横向模式不稳定性阈值以及光束质量都得到了显著提高。在整个连续运行过程中，LCT光纤放大器呈现出高功率稳定性，波动小于1%。这些结果表明，LCT光纤在保持优异光束质量的功率扩展方面具有巨大潜力。
