基于Sagnac型的双光路平衡探测光纤声传感器  

Double Balanced Detection of Optical Fiber Acoustic Sensor Based on Sagnac Interferometer

作　　者：朱剑锋[1] 

机构地区：[1]桂林电子科技大学电子工程与自动化学院,广西桂林541004

出　　处：《电子科技》2013年第9期47-49,共3页Electronic Science and Technology

摘　　要：为解决传统声电传声器易腐蚀、易受电磁干扰等问题,提出了一种用光纤提取声音的声光换能器结构。该传感器以Sagnac干涉仪为原型,利用声压作用于感应光纤产生的光弹效应实现光波相位的调制,采用3×3耦合器构建双光路平衡探测系统,通过干涉实现语音信号的解调,将光电转换后得到的幅值相等的两路信号进行差分处理,消除共模干扰信号和降低光源噪声。实验测试表明,系统性能稳定,波形失真小,在300～3 400 Hz范围内实现声音信号的提取与还原。In order to solve the problem that traditional acoustic-electric microphone is susceptible to corrosion and electromagnetic interference, an acoustic-optic transducer structure which uses optical fiber to extract the sound is proposed. In this paper, the sensor prototype is based on Sagnac interferometer, the sound pressure is used to act on photo-elastic effect which generated by the optical fiber to achieve light-phase modulation, and a 3 × 3 coupler is used to build dual optical path balanced detection system. The demodulation of the speech signal is done through in- terference, which can realize two equal amplitude＇ signals differential processing, eliminating common mode interfer- ence signal and reducing light source noise. The experiments show that the system is stable with small waveform dis- tortion. Voice signal extraction and restoration are implemented successfully in the range of 300 × 3400 Hz.

关 键 词：传声器 Sagnac干涉 光弹效应 双光路平衡探测 3×3耦合器 

分 类 号：TN247[电子电信—物理电子学]