In this paper, we study the power scaling in high power continuous-wave Raman fiber amplifier employing graded-index passive fiber. The maximum output power reaches 2.087 kW at 1130 nm with an optical conversion efficiency of 90.1% (the output signal power versus the depleted pump power). To the best of our knowledge, this is the highest power in the fields of Raman fiber lasers based merely on Stokes radiation. The beam quality parameter M2 improves from 15 to 8.9 during the power boosting process, then beam spot distortion appears at high power level. This is the first observation and analysis on erratic dynamic properties of the transverse modes in high power Raman fiber amplifier.

中文翻译：

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基于无源光纤的2 kW高效拉曼光纤放大器，具有光束清除和波动的动态分析。

在本文中，我们研究了采用渐变折射率无源光纤的高功率连续波拉曼光纤放大器的功率定标。在1130 nm处，最大输出功率达到2.087 kW，光转换效率为90.1％（输出信号功率与耗尽的泵浦功率）。据我们所知，这是仅基于斯托克斯辐射的拉曼光纤激光器领域中最高的功率。在功率提升过程中，光束质量参数M2从15提高到8.9，然后高功率水平出现束斑失真。这是大功率拉曼光纤放大器横向模态不稳定动态特性的首次观察和分析。