We report here for the first time, to the best of our knowledge, a direct laser diodes pumped 5 kW 1080 nm fiber amplifier using chirped and tilted fiber Bragg gratings (CTFBGs) to suppress stimulated Raman scattering (SRS). With one or two CTFBGs, which are carefully designed and fabricated to match the Raman gain spectrum, inserted between the seed and the amplifier stage, effective SRS suppression is obtained. The maximum suppression ratio is about 20 dB with one CTFBG and 27.5 dB with two when the amplifier operates at 5 kW, with beam quality factor M 2 of ∼1.8. By further improving the performance of CTFBGs and using more CTFBGs in a series, a better SRS suppression effect could be achieved, which is very useful for further power scaling of all-fiber laser systems.

中文翻译：

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使用chi和倾斜光纤布拉格光栅有效抑制直接激光二极管泵浦5千瓦光纤放大器中的受激拉曼散射

据我们所知，我们首次在此报告直接激光二极管泵浦的5 kW 1080 nm光纤放大器，该光纤放大器使用了倾斜和倾斜的光纤布拉格光栅（CTFBG）来抑制受激拉曼散射（SRS）。通过在种子级和放大器级之间插入一到两个精心设计和制造以匹配拉曼增益谱的CTFBG，可以获得有效的SRS抑制。当放大器在5 kW下工作时，一个CTFBG的最大抑制比约为20 dB，而两个CTFBG的最大抑制比约为27.5 dB，光束质量因数M 2为〜1.8。通过进一步提高CTFBG的性能并串联使用更多的CTFBG，可以获得更好的SRS抑制效果，这对于进一步提高全光纤激光器系统的功率缩放非常有用。