一种基于复合金属薄膜的EFPI型光纤声波传感器

An EFPI Type Fiber Optic Acoustic Wave Sensor Based on Composite Metal Thin Film

摘要:

采用非本征法布里-珀罗干涉(EFPI)方案,设计了一种基于铬金复合金属薄膜的声波传感器,采用基于快速傅里叶变换的相位解调方法解调光纤端面和换能薄膜之间的白光干涉,提高了相位灵敏度。实验结果表明,传感器在声波频率5~1000Hz内,灵敏度保持在-119.98~-120.99dB re 1 rad/μPa范围内,灵敏度变化小于1.01dB,具有较宽的响应平坦区间；在频率150Hz,声压0.18~5.30Pa的范围内工作稳定,且声压和相位之间具有良好的线性关系。

Abstract:

The extrinsic Fabry Perot interference scheme was used to design an acoustic wave sensor based on chromium gold composite metal thin film. At the same time, the phase demodulation method based on fast Fourier transform was used to demodulate the white light interference between the optical fiber end face and the energy conversion film, which improved the phase sensitivity. The experimental results show that the sensitivity of the sensor remains in the range of -119.98~-120.99dB re 1rad/μPa in the range of sound wave frequency of 5~1000Hz, and the sensitivity change is less than 1.01dB, with a wide response flat range. It works stably in frequency 150Hz and in the range of sound pressure 0.18~5.30Pa, and there is a good linear relationship between sound pressure and phase.