300 W侧面分布式抽运掺Yb全光纤放大器

采用角度磨抛的方式, 在纤芯/包层为20/400 μm双包层掺Yb光纤上制作了侧面抽运耦合器. 该耦合器对975 nm的半导体二极管抽运光的耦合效率最高可达97%, 对1080 nm信号光的泄漏比小于2%. 分析了侧面抽运耦合器的性能以及多个侧面抽运耦合器的级联分布对抽运耦合效率的影响; 同时, 在前向抽运和双向抽运方式下, 分析了级联耦合器的分布及信号光泄漏比对激光器整体效率的影响, 并进行了数值模拟. 采用自行研制的侧面抽运耦合器, 搭建了侧面耦合分布式抽运、掺Yb双包层全光纤主振荡功率放大器, 获得了波长为1080 nm、功率为303 W 的基模激光输出. 进一步增加抽运点个数, 提高抽运功率, 可获得更高的输出功率.

300 W all-fiber amplifier with distributed side-coupled pump configuration

The angle-polished side-pump coupler is fabricated by fused splicing angle-polished multimode fibers and 20/400 μm double-clad Yb-doped large mode area fiber together. The coupling efficiency of side-pumped coupler for 975 nm pumping light can reach up to 97%, and the leakage ratio of 1080 nm signal light is less than 2%. We analyze the performance of a single side-pumped coupler and also the influence of the distribution of cascade stage couplers on the efficiency of fiber amplifier. Using self-developed side-pumped couplers, we build a distributed side-pumped, ytterbium-doped double-clad all-fiber master oscillator amplifier, and an continuous and single mode laser of 1080 nm wavelength with a 303 W maximum output power is obtained. Finally, increasing the number of the side couplers to improve pump power, the output power of the amplifier becomes higher.