基于双波长解调的光纤干涉型传声器研究

提出了一种基于双波长解调的光纤法布里-珀罗(Fabry-Perot,FP)干涉型传声器,采用归一化算法和微分交叉相乘处理(DCM)算法,实现了声信号的准确还原.在归一化算法中,利用椭圆拟合,实现了两路波长光信号的归一化,减小了激光器输出波动对光纤FP干涉型传声器输出特性的影响;在DCM算法中,通过信号处理及滤波,实现了声信号的准确输出,减小了温度等环境因素对光纤FP干涉型传声器输出特性的影响.在实验中,采用对比法,测试了基于双波长解调的光纤FP干涉型传声器的特性,结果显示器件实现了灵敏度为210 mV/Pa、频率响应为100～3 15 0 H z的声信号测量,能够很好地应用于语音识别、噪声测量、空气声探测等领域.

Research on The Optical Fiber Interference Microphone with Dual Wavelength Demodulation

The optical fiber Fabry-Perot (FP) interference microphone with dual wavelength demodulation is demonstrated. By adopting the normalization algorithm and differential cross multiplication (DCM) algorithm, the acoustic signal is accurately restored. In the normalization algorithm, through ellipse fitting, the optical signal with two-way wavelength is normalized, which can reduce the influence of the output fluctuation of laser on the output of optical fiber FP interference microphone. In the DCM algorithm, through signal processing and filtering, the accurate output of acoustic signal is realized, and the influence of temperature and other environmental factors on the output of optical fiber FP interference microphone is reduced. In the experiment, the characteristics of optical fiber FP interference microphone based on dual wavelength demodulation are tested by contrast method. The acoustic signal with sensitivity of 210mV/Pa and frequency response of 100~3150Hz is realized, which can be well applied in the fields of speech recognition, noise measurement and airborne acoustic detection.