光纤法-珀腔声传感器温度特性研究

利用低精细度法-珀干涉原理，建立了光纤法-珀腔声传感器的温度数学模型，包括干涉光谱随温度变化的关系和声传感器输出信号随温度变化的关系.利用建立的温度数学模型，并通过仿真分析和实验验证，分析了影响光纤法-珀腔声传感器温度特性的关键-材料的热膨胀系数差异.提出复合光纤插芯结构，获得较大的热膨胀系数，以补偿腔长的变化，从而使光纤法-珀腔声传感器具有良好温度适应性.对采用复合光纤插芯的光纤法-珀腔声传感器进行了测试，测试结果表明，在-20~+40℃温度范围内，该传感器具有良好的温度适应性. 

Characteristics on Temperature of Fiber Acoustic Sensor Based on Fiber Fabry-Perot Cavity

A temperature model of fiber acoustic sensors based on fiber Fabry-Perot cavity was proposed, according to the principle of Fabry-Perot interference with low fineness. The temperature model was mainly arranged with the relationships between the interference spectroscopy and temperature, and between the output of the sensor and temperature. According to the model, simulation and experiments results show that, the key factor affecting the temperature characteristics of the sensor is attributed to the difference of the expansion coefficient of materials. To overcome the effects of temperature, a composite fiber ferrule was proposed. A composite ferrule with large expansion coefficient was designed to compensate the length change of fiber Fabry-Perot. This can improve the temperature adaptability of the sensors. The fiber Fabry-Perot cavity acoustic sensor with composite fiber ferrule was tested. The experimental results show that, it can work well in the temperature range of-20~+40℃.