测量微振动的光纤Sagnac干涉传感器

提出了一种光纤Sagnac干涉传感器,用于固体表面传播的超声波产生的微弱振动检测.当超声波信号在固体中传播并作用于光纤传感器的敏感环时,干涉仪的输出光强度受到了超声信号的调制;通过检测干涉仪的输出光强度并利用Fourier变换,获得了超声信号的频率特征.对传感系统的相位调制特性进行了仿真,并对实验结果进行了分析,结果表明该系统可用于固体中传播的超声波的频率特征识别.

Optical fiber Sagnac interferometeric sensor for measurement of feeble vibration

An optical fiber sensor based on Sagnac interferometer for the measurement of the feeble vibration produced by ultrasonic wave propagated on the surface of a solid plate is proposed.The output optical intensity of interferometer is modulated when ultrasonic wave signal passes through and acts on the sensitive coil of the Sagnac interferometer in the solid plate.The frequency characteristics of ultrasonic signal are obtained by detecting the output optical intensity of interferometer and using Fourier transform technique.Phase-modulation property of optical fiber sensor is emulated and experiment results are also analyzed,which show that the system could be used to identify the ultrasonic frequency characteristics on the surface of the solid plate transmission.