High-Sensitivity Fabry-Perot Interferometric Acoustic Sensor for Low-Frequency Acoustic Pressure Detections

• Published in: Journal of lightwave technology Vol. 35; no. 24; pp. 5276 - 5279
• Main Authors: Gong, Zhenfeng, Chen, Ke, Zhou, Xinlei, Yang, Yang, Zhao, Zhihao, Zou, Helin, Yu, Qingxu
• Format: Journal Article
• Language: English
• Published: New York IEEE 15.12.2017; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Acoustic noise; Acoustic pressure detection; Acoustic sensors; Acoustics; Diaphragms; Dynamic pressure; Fabry-Perot; Fiber optics; fiber optics sensors; Frequency response; Interferometry; Optical fiber sensors; Optical fibers; Security systems; Sensitivity; Sensors
• ISSN: 0733-8724; 1558-2213
• DOI: 10.1109/JLT.2017.2761778

We demonstrate a fiber-optic Fabry-Perot acoustic sensor based on a Parylene-C diaphragm of 500 nm in thickness. The excellent diaphragm forming ability and good adhesion of Parylene-C make the sensor fabricate up to 9 mm in diameter. Acoustic testing demonstrates a high dynamic pressure sensitivity of 2239 nm/Pa and a noise limited equivalent acoustic signal level of 22.1 μPa/Hz 1/2 at the frequency of 20 Hz. The frequency response exhibits an obvious peak at the frequency of 13 Hz. The sensor can be used for low-frequency acoustic pressure detections, which is necessary in surveillance and security systems.