High-resolution micro-grating accelerometer based on a gram-scale proof mass

Micro-grating accelerometer detecting small displacement by an optical system can be widely applied in inertial navigation and seismic monitoring. We proposed a micro-grating accelerometer prototype with a proof mass of gram-scale to decrease the thermal mechanical noise, which is the fundamental limit of a high-resolution accelerometer. The theoretical model for the contrast ratio of a micro-grating accelerometer is established based on Gaussian beam theory, and the adjustment method based on a scanning slit beam profiler improves the contrast ratio of 0th order effectively. Compared to our former prototype, experiment results indicate the noise floor is decreased from 0.9 mg/root Hz to 137 mg/root Hz, and the bias stability is decreased from 0.35 mg to 3.1 mu g. (C) 2019 Optical Society of America under the terms of the OSA Open Access Publishing Agreement