A novel fast measurement method based on Brillouin gain spectrum (BGS) and Brillouin beat spectrum (BBS) in a complex index profile fiber has been proposed to realize simultaneous measurement of distributed temperature and strain. An interesting phenomenon that the temperature/strain sensitivities of the power on the BGS slope and the power on the BBS peak are very different has been discovered and utilized for temperature and strain sensing. By means of only measuring the power trace of the BGS slope and the power trace of one BBS peak along the sensing fiber, the distributed temperature and strain can be measured by using the Brillouin optical time-domain reflectometry (BOTDR) without scanning the Brillouin spectrum. The temperature and strain measurement uncertainties of the proposed method are one order of magnitude lower than that of the BBS-based measurement method. In a proof-of- concept experiment, the temperature and strain of the 2 km large effective area fiber (LEAF) are measured at a spatial resolution of 3 m within 18 s.

中文翻译：

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基于布里渊增益谱和布里渊拍频的分布式温度和应变测量

提出了一种基于布里渊增益谱（BGS）和布里渊拍频（BBS）的复杂折射率分布光纤快速测量方法，实现分布式温度和应变的同时测量。发现了一个有趣的现象，即 BGS 斜率上的功率和 BBS 峰上的功率的温度/应变灵敏度非常不同，并将其用于温度和应变传感。通过仅测量BGS斜率的功率迹线和沿传感光纤的一个BBS峰的功率迹线，无需扫描布里渊光谱即可使用布里渊光时域反射计（BOTDR）测量分布温度和应变. 该方法的温度和应变测量不确定度比基于 BBS 的测量方法低一个数量级。在概念验证实验中，在 18 秒内以 3 m 的空间分辨率测量了 2 km 大有效面积光纤 (LEAF) 的温度和应变。