基于Sagnac干涉仪的新型声源定位光纤传感器

Optical Fiber Sensor for Sound Source Location Based on Sagnac Interferometer

利用法拉第旋转镜(FRM)把Sagnac光纤干涉仪的环形光纤臂改成单臂直线结构的新型零程差干涉仪,克服了传统Sagnac光纤干涉仪结构上的缺点。另外,FRM作为偏振补偿器解决了偏振诱导信号衰弱问题。对该装置进行了理论分析,并以管道的泄漏声为例进行了实验研究,实验结果与理论分析相吻合,定位误差小于1%,表明该装置可以实现宽频声信号源的定位。

The novel zero-path-difference interferometer,of which the annular fiber arm of Sagnac interferometer is converted into linear structure by using a Faraday rotator mirror （FRM） ,can overcome the shortcoming of traditional optical fiber Sagnac interferometer. Moreover,FRM being used as a polarization compensator eliminates the problem of the polarization-induced signal fading. This device was analyzed in theory and sound field leakage of pipeline was studied as an example in experiment. The experimental result accords with the theoretic analysis and the location inaccuracy is less than 1% ,which shows that the novel device can realize the detection and location of the wideband sound signal source.