Appl Opt. 2023 May 1;62(13):3338-3346. doi: 10.1364/AO.486951.
Most of the existing schemes for extracting the Brillouin frequency shift (BFS) are based on the line shape of the Brillouin gain spectrum (BGS) curve. However, in some circumstances, such as in this paper, there is a cyclic shift in the BGS curve, causing difficulty in obtaining the BFS accurately with traditional methods. To solve this problem, we propose a method for extracting Brillouin optical time domain analyzer sensing information in the transform domain-the fast Fourier Lorentz curve fitting method. It shows better performance especially when the cyclic start frequency is near the BGS central frequency position or when the full width at half maximum is large. The results show that our method can obtain BGS parameters more accurately in most cases than the Lorenz curve fitting method.
大多数提取布里渊频移（BFS）的现有方案都是基于布里渊增益谱（BGS）曲线的线型。然而，在某些情况下，如图中所示，BGS 曲线存在循环移动，这使得传统方法难以准确获得 BFS。为了解决这个问题，我们提出了一种在变换域中提取布里渊光时域分析传感信息的方法——快速傅里叶洛伦兹曲线拟合方法。该方法在循环起始频率接近 BGS 中心频率位置或半峰全宽较大时表现出更好的性能。结果表明，在大多数情况下，我们的方法比洛伦兹曲线拟合方法能更准确地获得 BGS 参数。
