High-Speed Mach-Zehnder-OTDR Distributed Optical Fiber Vibration Sensor Using Medium-Coherence Laser  

作　　者：Yuheng TONG Zhengying LI Jiaqi WANG Honghai WANG Haihu YU 

机构地区：[1]National Engineering Laboratory for Fiber Optic Sensing Technology, Wuhan University of Technology, Wuhan 430070, China

出　　处：《Photonic Sensors》2018年第3期203-212,共10页光子传感器（英文版）

基　　金：This work was supported in part by the National Natural Science Foundation of China （Gram No. 61735031）, Natural Science Foundation of Hubei Province of China （Grant No. 2018CFA056）, and the Excellent Dissertation Cultivation Funds of Wuhan University of Technology （Grant No. 2017-YS-057）.

摘　　要：This article presents a high-speed distributed vibration sensing based on Mach-Zehnder-OTDR （optical time-domain reflectometry）. Ultra-weak fiber Bragg gratings （UWFBG）, whose backward light intensity is 2-4 orders of magnitude higher than that of Rayleigh scattering, are used as the reflection markers. A medium-coherence laser can substitute conventional narrow bandwidth source to achieve an excellent performance of distributed vibration sensing since our unbalanced interferometer matches the interval of UWFBGs. The 3 m of spatial resolution of coherent detection and multiple simultaneous vibration sources locating can be realized based on OTDR. The enhanced signal to noise ratio （SNR） enables fast detection of distributed vibration without averaging. The fastest vibration of 25 kHz and the slowest vibration of 10Hz can be detected with our system successfully, and the linearity is 0.9896 with a maximum deviation of 3.46nε.This article presents a high-speed distributed vibration sensing based on Mach-Zehnder-OTDR （optical time-domain reflectometry）. Ultra-weak fiber Bragg gratings （UWFBG）, whose backward light intensity is 2-4 orders of magnitude higher than that of Rayleigh scattering, are used as the reflection markers. A medium-coherence laser can substitute conventional narrow bandwidth source to achieve an excellent performance of distributed vibration sensing since our unbalanced interferometer matches the interval of UWFBGs. The 3 m of spatial resolution of coherent detection and multiple simultaneous vibration sources locating can be realized based on OTDR. The enhanced signal to noise ratio （SNR） enables fast detection of distributed vibration without averaging. The fastest vibration of 25 kHz and the slowest vibration of 10Hz can be detected with our system successfully, and the linearity is 0.9896 with a maximum deviation of 3.46nε.

关 键 词：HIGH-SPEED Mach-Zehnder-OTDR ultra-weak fiber Bragg grating array medium-coherence laser optical fiber vibration sensing 

分 类 号：TP273.4[自动化与计算机技术—检测技术与自动化装置] TQ342.82[自动化与计算机技术—控制科学与工程]