This paper comprehensively investigated noise characteristics of superluminal propagation based on low-noise single-frequency Brillouin lasing oscillation with the aid of a population inversion dynamic grating. Thanks to high-degree polarization alignment between the Brillouin pump and the lased Stokes lightwaves in polarization maintaining fibers, efficient Brillouin lasing resonance with over 10-dB relative intensity noise suppression has been demonstrated to activate Brillouin loss-induced anomalous dispersion in the vicinity of pump signals, benefiting a noise-insensitive superluminal propagation along kilometer-long optical fibers with robust resistance to ambient disturbance. Consequently, sinusoidally modulated pump signals experienced the time advancement of 4634.0 ns at the group velocity of 10.63 c . Results show that the variance of the fractional advancement with polarization maintaining fibers is 2.54 × 10 ⁻⁴ which is two orders of magnitude lower than that of conventional single mode fibers. Furthermore, the dependence of the group velocity on the modulation frequency was experimentally investigated, showing good agreement with the theoretical analysis.

中文翻译：

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基于偏振匹配低噪声布里渊激光谐振的稳定长距离超光速传播

本文借助粒子数反转动态光栅，综合研究了基于低噪声单频布里渊激光振荡的超光速传播噪声特性。由于布里渊泵浦和保偏光纤中的激光斯托克斯光波之间的高度偏振对准，已证明具有超过 10 dB 相对强度噪声抑制的有效布里渊激光谐振可激活泵浦附近的布里渊损耗引起的异常色散信号，有利于沿公里长的光纤进行噪声不敏感的超光速传播，对环境干扰具有强大的抵抗力。因此，正弦调制的泵浦信号在 10.63 的群速度下经历了 4634.0 ns 的时间推进 C 。结果表明，保偏光纤的分数推进的方差为2.54×10 ^-4，比传统的单模光纤低两个数量级。此外，通过实验研究了群速度对调制频率的依赖性，表明与理论分析非常吻合。