基于钛膜的光纤F-P声波传感器实现

Realization of Optical Fiber F-P Acoustic Sensor Based on Titanium Film

针对电子式声波传感器易受电磁干扰的问题,根据非本征型法布里-珀罗(EFPI)干涉结构,提出了一种基于钛膜的光纤F-P声波传感器,其利用钛膜受压形变引起F-P腔长变化实现声光换能。搭建稳定正交工作点的强度解调系统,用于降低温度漂移对解调精度的影响。经实验证明,该传感器干涉光谱消光比约12 dB;能够实现1.5~8 kHz正弦声波信号的探测,系统信噪比约45 dB;在强度响应测试中,拟合曲线的线性度大于0.982,表明传感器具有良好的线性响应关系。

To address the susceptibility of electronic acoustic wave sensors to electromagnetic interference,a fiber-optic F-P acoustic wave sensor based on a titanium membrane was proposed according to the EFPI structure,which used the change in F-Pcavity length caused by deformation of the titanium membrane under compression to achieve acousto-optic energy conversion.To limit the effect of temperature drift on demodulation accuracy,an intensity demodulation system with stabilized orthogonal working points was designed and used.The extinction ratio of the sensor s interferometric spectrum is ap proximately 12 dB,it can detect sinusoidal acoustic signals ranging from 1.5 kHz to 8 kHz, with a signal-to-noise ratio of approximately 45 dB, and the linearity of the fitted curves in the intensity response test is greater than 0.982,indicating that the sensor has a good linear response relationship.