Ye Yun, Lin Xianfeng, Yang Baolai, Xi Xiaoming, Shi Chen, Zhang Hanwei, Wang Xiaolin, Li Jinyan, Xu Xiaojun
Opt Lett. 2022 May 1;47(9):2162-2165. doi: 10.1364/OL.457529.
In this Letter, we demonstrate a monolithic high-power master oscillator power amplifier by using a home-made double-clad tapered Yb-doped fiber (T-YDF) with an input end of ∼20/400 µm and an output end of ∼30/600 µm. Thanks to perfect core/cladding matching with the fiber components at both ends of the T-YDF, the laser is pumped bidirectionally and an output power of over 4 kW with a high slope efficiency of 84.1% and excellent beam quality M ∼ 1.46 is achieved. In contrast to previous work on common fiber lasers, experimental results also reveal that the co-pump scheme has a higher transverse mode instability (TMI) threshold and power-boosting capability than that of a counter-pump scheme. To the best of our knowledge, this is the highest output power demonstrated to date from such a T-YDF with excellent beam quality. This work indicates the great potential of the T-YDF to realize further power scaling, high laser efficiency, and excellent beam quality in high-power fiber lasers.
在本信函中，我们展示了一种单片高功率主振荡功率放大器，它采用了自制的双包层锥形掺镱光纤（T-YDF），其输入端约为20/400 µm，输出端约为30/600 µm。由于T-YDF两端的光纤组件实现了完美的纤芯/包层匹配，激光器采用双向泵浦，实现了超过4 kW的输出功率，具有84.1%的高斜率效率和M²~1.46的优异光束质量。与之前关于普通光纤激光器的工作相比，实验结果还表明，同向泵浦方案比反向泵浦方案具有更高的横向模式不稳定性（TMI）阈值和功率提升能力。据我们所知，这是迄今为止从这种具有优异光束质量的T-YDF获得的最高输出功率。这项工作表明T-YDF在实现高功率光纤激光器的进一步功率缩放、高激光效率和优异光束质量方面具有巨大潜力。
