相位调制单频激光产生多波长激光具有操作简单、成本低的特点，可有效抑制窄线宽光纤放大器中的受激布里渊散射（SBS）效应。理论研究了波长数目、波长成分相对强度与调制信号之间的关系，当调制频率较小时（如约100 MHz），调制产生的多频激光可以有效提高SBS阈值。实验研究了调制频率为100 MHz的相位调制对高功率窄线宽光纤放大器中SBS的抑制效果。在放大器末端熔接16 m和26.5 m传能光纤的情况下，SBS阈值输出功率分别为相应的未调制时的2.5倍和3.7倍。实验结果表明，利用相位调制可以有效抑制窄线宽光纤放大器中的SBS效应，且抑制效果与系统参数有关，未调制时的SBS阈值越低，效果越好。

Phase modulation of the single frequency laser to attain the multi-tone laser costs less and is easy to carry out. It has been proved to be an effective way to suppress stimulated Brillouin scattering (SBS) in narrow-linewidth fiber amplifiers. Relationships between modulation signals and constitutions of the modulated laser are studied theoretically. When the modulation frequency is small, for example 100 MHz, the multi-frequency laser can be attained and SBS threshold is effectively enhanced. Experimental researches are done to study effects of 100 MHz phase modulation on SBS mitigation of high power narrow linewidth fiber amplifiers. SBS threshold output powers are 2.5 times and 3.7 times of that of the corresponding unmodulated amplifiers with 16 and 26.5 m delivery fiber respectively. Experimental results show that SBS in narrow-linewidth fiber amplifiers can be effectively suppressed with phase modulation and the suppression effect depends on amplifiers′ parameters. The lower the SBS threshold without modulation, the better the suppression effect.