介绍了一种基于反射式强度型光纤传感原理的光纤声传感器,该传感器通过光纤模块将发射光纤和接收光纤的夹角固定为60°,同时采用基于微加工技术制作的反射振动膜片敏感声音信号并调制光信号强度。建立了该传感器的理论模型,并通过仿真和实验分析得到系统的最佳工作距离为8μm,灵敏度为2.49μW/μm。实验测试结果表明,该声传感器样机对声音的探测灵敏度为30mV/Pa,同时给出了样机的频率响应及线性度测试结果。
An acoustic sensor based on the reflective intensity modulated fiber optic sensing principle was described in this paper. The angle between the transmitting fiber and the receiving fiber was fixed at 60°through the optic fiber module in the sensor,the acoustic signals were sensed and the optic signal intensity was modulated by the reflective vibration membrane manufactrued by the micro-machined technique. The theoretical model of the sensor is established. The simulation and experminental results showed that the optimum distance of the system was 8 μm and the sensitivity was 2.49 μW/μm. The test results indicated that the sensor prototype has the sensitivity of 30 mV/Pa to the acoustic signal. The test results of the frequency response and linear response were also given in this paper.