论文标题
高效型Holmium掺杂的三层纤维激光器在2120 nm处
High efficiency holmium-doped triple-clad fiber laser at 2120 nm
论文作者
论文摘要
我们开发了一种新的掺杂的三层纤维纤维（HO-3CF），从而降低了外壳直径以改善泵和掺杂核之间的重叠，并降低了Holmium浓度，以降低离子簇对激光效率的影响。我们在这里说明了该光纤在激光振荡器配置中的性能。激光发射以2.12 $ $ m的含量为中心，由纤维bragg光栅，并将活性纤维泵入外壳中的1.94 $ $ m $ m $ m $ m thulium掺杂的纤维激光器。相对于吸收功率，坡度效率达到73％（考虑到耦合功率的60％），对于在准单个空间模式下传递的62 W的最大信号功率（M $^2 $ = 1.2）。据我们所知，这种坡度效率是高功率齐全的纤维激光器的报告最高的，其波长高于2.1 $μ$ m。我们还通过实验分析了泵数值孔径（Na）在HO-3CF输入中对激光效率的影响。最后，我们使用数值模拟来评论泵波长的最佳选择。
We developed a new holmium-doped triple-clad fiber (Ho-3CF), reducing the clad diameter to improve the overlap between pump and doped-core, and the holmium concentration to reduce the influence of ion clustering on the laser efficiency. We illustrate here the performance of this fiber in a laser oscillator configuration. The laser emission is centered at 2.12 $μ$m by a fiber Bragg grating, and the active fiber is pumped in the clad by a 1.94 $μ$m thulium-doped fiber laser. The slope efficiency reaches 73% with respect to absorbed power (60% considering coupled power), for a maximum signal power of 62 W delivered on a quasi single spatial mode (M$^2$=1.2). To the best of our knowledge, this slope efficiency is the highest reported for a high power clad-pumped fiber laser emitting at a wavelength higher than 2.1 $μ$m. We also analyze experimentally the impact of the pump Numerical Aperture (NA), at the input of the Ho-3CF, on the laser efficiency. Finally, we use our numerical simulation to comment on the best choice of pump wavelength.
