布里渊散射光纤传感器的交叉敏感问题

Cross Sensitivity of Brillouin Scattering Distributed Fiber Sensor

基于布里渊散射的全分布式光纤传感器的布里渊频移同时受应变和温度的影响,无法由单一的布里渊频移解析应变或温度的信息,这种交叉敏感问题制约了传感器的实用化。介绍了目前解决交叉敏感问题的主要方法及工作原理。研究了大有效面积非零色散位移光纤(LEAF)的布里渊散射谱与应变和温度的关系,实验发现布里渊谱具有三个布里渊峰,三个峰的布里渊频移与应变和温度成线性关系,第一个峰和第三个峰的布里渊峰峰值功率的差值与温度无关,但与应变成线性关系。最后基于实验结果提出了一种解决交叉敏感问题的方案,获得了大约130με的应变测量精度和8℃的温度测量精度。

Brillouin frequency shift in a Brillouin scattering-based fully distributed fiber sensor is the combined effects of strain and temperature. A single Brillouin frequency shift can＇t achieve the information of strain and temperature, respectively, and the cross sensitivity limits the practice of the sensor. The present methods and working principles for solving the cross sensitivity are introduced. The relationship between Brillouin-scattering spectrum and strain or temperature of large effective area non-zero dispersion-shifted fiber （LEAF） is investigated. It is found that there are three Brillouin scattering peaks in the spectrum, which are linear with strain and temperature. The difference of Brillouin intensity between the first peak and the third peak is independent of temperature but is linear with strain. A resolution to solve the cross-sensitivity problem based on experimental results is given, and about 130με strain and 8℃ temperature measurement resolution is achieved.