A MEMS fiber-optic Fabry-Perot accelerometer with spectral-phase demodulation

In this work, a wideband Fabry-Perot accelerometer based on MEMS diagram was proposed and designed. The central mass block was elastically connected to a 2.8 mm outer frame through four curved beams to construct a single degree of freedom vibration system. Based on finite element simulation, the structural parameters of the four-arm bending beam diaphragm are optimized to broaden the operating frequency band while improving sensitivity. The structural stability of the sensor is ensured by leveraging MEMS processing technology, and miniaturized packaging is realized through the application of ceramic brackets. Moreover, a spectral-phase demodulation algorithm is employed to enable high-resolution measurement with a large vibration range. Through the in-depth analysis of experimental data, it is concluded that the designed accelerometer has an intrinsic frequency of 6624 Hz, an axial sensitivity of 12.397 nm/g at 200 Hz, and a lateral crosstalk of approximately 6.91 %. The working range of the accelerometer is 0 ∼ 2000 Hz, with a resolution of 14.358 mg and a measurement range of ± 287 g. The accelerometer exhibits sensitive response capability, large dynamic range and high stability, demonstrating great potential for application in diverse fields such as aerospace, mechanical and civil engineering.