Large-Dynamic-Range and High-Resolution Fiber Optic Accelerometer Based on Spectral Interferometry Phase Demodulation

Optical fiber accelerometers featuring large dynamic range and high resolution are essential sensors in the fields of aerospace engineering, civil infrastructure monitoring, and geophysical exploration. To address these technical demands, this study presents a micro-gravity fiber optic accelerometer based on spectral interferometry phase demodulation. The accelerometer integrates a double-spring-supported oscillator for wideband operation, coupled with a fiber Fabry-Perot interferometer (FPI) for highly sensitive acceleration reading. A spectral phase demodulation method is further developed to realize acceleration measurement with high resolution and large dynamic range. Because of the spectral phase demodulation method, a low noise floor of 0.54 μg/Hz1/2combined with an operational dynamic range exceeding 132 dB across the frequency range of 50-300 Hz are achieved by the proposed FPI accelerometer experimentally. The developed FPI accelerometer is simple yet robust, particularly suitable for practical deployment in challenging environments of spacecraft vibration monitoring.