Extrinsic Fabry–Perot Cantilever Accelerometer Based on Micromachined 45° Angled Fiber

High-sensitivity extrinsic Fabry-Perot cantilever accelerometers were proposed and tested. Micromachined 45° angled fiber was adopted to form the cantilever to measure the acceleration. The Fabry-Perot cavity was formed by the sidewall of the fiber and the inner surface of commercial ceramic sleeves. The stepped cantilever fiber was fabricated by etching method to improve the sensitivity without enlarging the cantilever's length or adding extra proof-mass. Detailed theoretical analysis, simulation, and experimental results of the proposed accelerometers were given. The measured results were in good agreement with the simulated results. The proposed accelerometers show the advantages of high flexibility, simplicity, compactness, and low cost, which are expected to be applied in the field of miniaturized vector hydrophone and seismic monitoring.