In this paper, we demonstrate a self-homodyne coherent system with a significantly narrowed effective linewidth using optical carrier recovery based on stimulated Brillouin scattering (SBS), employing only coarse path length matching. The effective linewidth of the SBS-based receiver system is reduced from 75 kHz to less than 2 kHz, which is estimated by Lorentzian fitting of power spectra, and confirmed by simulation results of the tolerance window length for phase noise compensation (PNC) with different linewidth. Both experimental and numerical studies on the tracking requirements on PNC algorithms confirm effective linewidth reduction to this level, and show a 32x relaxation of the phase recovery tracking window length. This highlights the potential to significantly reduce the computational complexity of PNC even in coarsely optimized SBS-based self-homodyne coherent systems, providing an alternative to using demanding ultra-low linewidth lasers.

中文翻译：

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通过基于受激布里渊散射的光载波恢复有效减少自零差相干接收的线宽

在本文中，我们使用基于受激布里渊散射 (SBS) 的光载波恢复，仅采用粗略的路径长度匹配，展示了一种有效线宽显着变窄的自零差相干系统。基于 SBS 的接收机系统的有效线宽从 75 kHz 减少到小于 2 kHz，这是通过功率谱的洛伦兹拟合估计的，并通过不同相位噪声补偿 (PNC) 的容限窗口长度的仿真结果证实行宽。关于 PNC 算法跟踪要求的实验和数值研究都证实了这一水平的有效线宽减小，并显示了相位恢复跟踪窗口长度的 32 倍松弛。