A MEMS Fiber-Optic Fabry-Perot Vibration Sensor for High-Temperature Applications

An extrinsic high-temperature fiber-optic Fabry-Perot vibration sensor based on MEMS technology is described and experimentally demonstrated. The sensitive unit consists of four cross beams with a central seismic mass batch-fabricated on a silicon wafer. The sensing head is fabricated by MEMS technology including dry etching, anodic bonding and dicing processing. And the optical fiber is intergrated in the sensing head by laser fusing. According to our calculation, the sensor has a resonance frequency of 10.008kHz. Experimental results indicated that the sensitivity of the sensor from 2g to 22g, with the frequency of 200Hz, was 2.48 nm/g at 20° and can work stably at 400°. The nonlinearity of the sensor was evaluated from 20° to 400° and the max nonlinear error was 1.88% at 300°. In addition, the temperature drift and temperature crossed sensitivity of the sensor agreed well with the theoretical analysis. We believe this proposed MEMS vibration sensor has a wide engineering high-temperature application prospect.