Zhong Penglin, Wang Li, Yang Baolai, Zhang Hanwei, Xi Xiaoming, Wang Peng, Wang Xiaolin
Opt Lett. 2022 Jun 1;47(11):2806-2809. doi: 10.1364/OL.458581.
Traditional monolithic fiber lasers can only achieve unidirectional high-power laser output. In this Letter, a novel high-power linear cavity fiber laser that can achieve bidirectional high-power output is proposed and demonstrated. In an ordinary laser resonant cavity, we replace the high-reflectivity fiber Bragg grating with a low-reflectivity fiber Bragg grating to realize bidirectional laser output. In our experiment, the laser cavity was composed of two fiber Bragg gratings with a reflectivity of about 10%. The pump power provided by the 976 nm laser diodes was injected into a double-clad Yb-doped fiber with core/cladding diameters of 20/400 µm. At the maximum pump power, the bidirectional output powers were 2025 W and 1948 W, respectively, and the output laser beam quality (M factor) at both ends was about 1.5. For the first time, to the best of our knowledge, the feasibility of a bidirectional output fiber laser that can achieve double high (2-kW-level) power was verified. Compared with a traditional unidirectional output laser, this type of bidirectional output laser can achieve a double high-power laser by employing a laser resonant cavity. Thus, the average cost and structure size can be further reduced in mass production.
传统的单块光纤激光器只能实现单向高功率激光输出。在本信函中，提出并演示了一种能够实现双向高功率输出的新型高功率线性腔光纤激光器。在普通激光谐振腔中，我们用低反射率光纤布拉格光栅取代高反射率光纤布拉格光栅来实现双向激光输出。在我们的实验中，激光腔由两个反射率约为10%的光纤布拉格光栅组成。由976 nm激光二极管提供的泵浦功率被注入到纤芯/包层直径为20/400 µm的双包层掺镱光纤中。在最大泵浦功率下，双向输出功率分别为2025 W和1948 W，两端的输出激光光束质量（M因子）约为1.5。据我们所知，首次验证了能够实现双高（2千瓦级）功率的双向输出光纤激光器的可行性。与传统的单向输出激光器相比，这种双向输出激光器通过采用激光谐振腔能够实现双高功率激光输出。因此，在大规模生产中可以进一步降低平均成本和结构尺寸。
