A Fiber-Optic Fabry-Perot Accelerometer Based on High-Speed White Light Interferometry Demodulation

• Published in: Journal of lightwave technology Vol. 36; no. 9; pp. 1562 - 1567
• Main Authors: Zhao, Zhihao, Yu, Zhihao, Chen, Ke, Yu, Qingxu
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.05.2018; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Acceleration; Acceleration measurement; Accelerometers; Cavity resonators; Commercialization; Demodulation; Fabry-Perot interferometers; Fiber optics; High speed; Interferometry; Interrogation; Optical fiber sensors; Optical fibers; Piezoelectricity; Sensitivity; White light interferometry
• ISSN: 0733-8724; 1558-2213
• DOI: 10.1109/JLT.2017.2783882

A fiber-optic Fabry-Perot (F-P) accelerometer with high resolution, high dynamic range, high speed, and absolute measurement capability was developed and demonstrated in elevator health monitoring. The sensor element is based on a mesh diaphragm mass-loaded compact structure, and the F-P cavity interrogation was achieved by utilizing a high-speed white light interferometry demodulation algorithm. The displacement of inertial mass representing the change of F-P cavity was measured and translated to acceleration in real time. The results indicate a resonance frequency of 270 Hz and axial sensitivity of 3.86 μm/g within the frequency bandwidth of 10-120 Hz for the sensor. In experimental tests, the acceleration resolution achieved 8.5 μg within a ± 30 g maximum measurement range. The performance of the sensing system was compared with a commercialized piezoelectric accelerometer in monitoring the acceleration of an elevator.