High sensitivity fiber optic acceleration sensor based on Fabry-Perot interferometer

A high sensitivity fiber optic acceleration sensor based on Fabry-Perot interferometer is proposed and experimentally demonstrated. The proposed sensor is composed of a sensor pedestal, a mass block, elastic diaphragm and two reflectors, wherein the collimating reflector 1 and the reflector 2 constitute a fiber Fabry-Perot (F-P) interference cavity. By analyzing the relevant parameters of F-P interference theory, we modulate the F-P reflection spectrum with high finesse, and demodulate the F-P reflection spectrum by wavelength demodulation method to obtain the acceleration signal. Through simulation analysis and experimental verification, the resonant frequency, sensitivity and lateral anti-interference ability of the sensor have been investigated. The experimental results show that the resonant frequency of the sensor is 800 Hz, the sensitivity is 3.81 nm/g when the frequency is 300 Hz, the resolution is 0.263 mg, and the lateral anti-interference degree is less than 5 %. Furthermore, the proposed acceleration sensor exhibits the advantages of simple structure and low cost, and has great application prospects in the vibration monitoring of the pitch bearing of wind power generation.