基于纤芯失配的光纤布拉格光栅温度不敏感振动传感器  

Temperature-independent fiber Bragg grating vibration sensor based on core-diameter-mismatch

作　　者：高平安[1] 冯定一[1] 杜彦英[1] 冯忠耀[1] 

机构地区：[1]西北大学物理学系,陕西西安710069

出　　处：《西北大学学报（自然科学版）》2013年第3期390-392,402,共4页Journal of Northwest University（Natural Science Edition）

摘　　要：提出了一种基于纤芯失配的光纤布拉格光栅温度不敏感传感结构并且得到了实验验证。该传感器由一短截细芯光纤和单模光纤布拉格光栅熔接而成。光通过细芯光纤时激发出一系列包层模式,并通过纤芯失配的熔接面进入后面的光纤布拉格光栅中。其中,一些低阶模式会被光纤光栅反射耦合回传输光纤的纤芯,耦合效率与光纤的弯曲度有关。实验结果表明低阶奇数膜LP3n对光纤弯曲度有极大的灵敏度。通过对包层模式的选择性监测和能量检测方法,提高了传感器的弯曲灵敏度,并避免了温度对传感器的影响。A novel temperature-independent fiber Bragg grating （FBG） sensing configuration based on a core-diam- eter-mismatch is proposed and experimentally demonstrated. The configuration is formed by a short section of thin- core fiber （TCF） followed with a single-mode fiber （SMF） tip inscribed with a FBG. The TCF excites cladding modes into downstream SMF via the mismatch-core splicing interface, and the low-order cladding modes can be re- flected back to the fiber core via the FBG in which the recoupling efficiency is highly dependent on fiber bending. Experimental results show that the recoupled low-order odd modes （ LP3n ） show an extremely high sensitivty to fiber bending. Power-referenced and temperature-independent vibration measurement with improved sensitivity has been achieved via selective cladding modes monitoring.

关 键 词：光纤传感 温度 振动 

分 类 号：O437.4[机械工程—光学工程]