Ren Shuai, Lai Wenchang, Wang Guangjian, Li Wei, Song Jiaxin, Chen Yisha, Ma Pengfei, Liu Wei, Zhou Pu
Opt Express. 2022 Feb 28;30(5):7845-7853. doi: 10.1364/OE.454189.
In this work, we conduct a detailed experimental study on the impact of signal bandwidth on the TMI threshold of fiber amplifiers. Both the filtered superfluorescent fiber sources and the phase-modulated single-frequency lasers are employed to construct seed lasers with different 3 dB spectral linewidths ranging from 0.19 nm to 7.97 nm. The TMI threshold of the fiber amplifier employing those seed lasers are estimated through the intensity evolution of the signal laser, and different criteria have been utilized to characterize the spectral linewidth of the seed lasers. Notably, the experimental results reveal that the TMI threshold of fiber amplifiers grows, keeps constant, and further grows as a function of spectral linewidth of seed lasers. Our experimental results could provide a well reference to understand the mechanism of the TMI effect and optimize the TMI effect in high-power fiber amplifiers.
在这项工作中，我们对信号带宽对光纤放大器的受激布里渊散射（TMI）阈值的影响进行了详细的实验研究。使用滤波后的超荧光光纤源和相位调制单频激光器来构建具有不同3 dB光谱线宽（范围从0.19 nm至7.97 nm）的种子激光器。通过信号激光的强度演变来估计采用这些种子激光器的光纤放大器的TMI阈值，并且已使用不同的标准来表征种子激光器的光谱线宽。值得注意的是，实验结果表明，光纤放大器的TMI阈值随着种子激光器光谱线宽的变化而增大、保持恒定并进一步增大。我们的实验结果可为理解TMI效应的机制以及优化高功率光纤放大器中的TMI效应提供很好的参考。
