光学学报, 2013, 33 (9): 0906001, 网络出版: 2013-08-27
基于光纤光栅法布里珀罗干涉仪的液体介质声波检测技术研究
Acoustic Detection Technology Based on Fiber Bragg Grating Fabry-Perot Interferometer in Liquid Medium
光纤光学 声波传感器 光纤光栅法布里珀罗干涉仪 圆筒振子灵敏度 温度补偿 fiber optics acoustic sensor fiber Bragg grating Fabry-Perot interferometer cylinder oscillator sensitivity temperature compensation
摘要
结合光纤光栅法布里珀罗干涉仪(FBG-FPI)和圆筒振子耦合技术设计高灵敏度传感器,应用于电力设备液体绝缘介质中声波信号检测。FBG-FPI采用反射率为50%的光纤布拉格光栅(FBG),中间处截断熔接20 mm长单模光纤SMF-28制备。为获得高灵敏度,根据弹性力学原理和有限元分析方法建立圆筒振子参数确定方法。为解决FBG-FPI受温度影响而造成静态工作点漂移的问题,提出了一种利用可调谐分布式反馈(DFB)激光器的温度补偿方法,并通过升降温实验验证了该方法的温度补偿效果。建立FBG-FPI传感器与RC6500T传感器对比实验系统,实验结果表明在1.1 kHz声波信号驱动下液体介质中的FBG-FPI与加速度传感器具有相近灵敏度。
Abstract
Combining with fiber Bragg grating Fabry-Perot interferometer (FBG-FPI) with cylinder oscillator coupling technology, a highly sensitive sensor is designed for detecting acoustic signal in liquid dielectrics of electrical equipment. A fiber Bragg gratting (FBG) with reflectivity of 50% is cut in the middle to produce two identical half-length Bragg gratings, and a piece of 20-mm SMF-28 monomode fiber is spliced between the FBGs to produce the FBG-FPI. The parameters of the cylinder oscillator are determined for high sensitivity by finite element analysis method based on the theory of elasticity. A novel method of temperature compensation using a tunable distributed feedback (DFB) laser is presented to solve FBG-FPI static working point drift influenced by temperature change. The effect of temperature compensation is proved by raising and falling temperature experiment. A contrast system with FBG-FPI sensor and RC6500T transducer is designed and constructed. The experimental results show that FBG-FPI in liquid dielectrics has the same sensitivity as acceleration transducer for the 1.1 kHz acoustic signal.
张伟超, 赵洪, 刘通, 王国利, 李锐海. 基于光纤光栅法布里珀罗干涉仪的液体介质声波检测技术研究[J]. 光学学报, 2013, 33(9): 0906001. Zhang Weichao, Zhao Hong, Liu Tong, Wang Guoli, Li Ruihai. Acoustic Detection Technology Based on Fiber Bragg Grating Fabry-Perot Interferometer in Liquid Medium[J]. Acta Optica Sinica, 2013, 33(9): 0906001.