Out-of-Plane Micrograting Accelerometer Based on Micro Opto Electromechanical Systems

This paper proposes a miniature micrograting accelerometer based on out-of-plane motion that integrates a laser, photodetector, resonator, grating, and an electromagnetic feedback module. A miniaturized accelerometer (dimensions of 6 cm × 4 cm × 3 cm) was developed, which introduced a structural stiffening effect to improve resonator safety. It functioned in a low-frequency working mode when the resonator was placed vertically. When placed horizontally, the stiffening effect enhanced the structural stiffness, increasing frequency, thereby preventing structural damage. In addition, an electromagnetic feedback module was integrated and could be used for closed loop operation to extend the measurable range. Compatibility between the designed structural parameters and the working mode was verified by finite-element simulations. The experimental results showed that the scale factor of the accelerometer could be optimized to 1216 V/g, the range could be extended to 6.49 mg, and the noise floor could be as low as 4 ng/√Hz. This accelerometer has great potential for use in monitoring micro vibrations, gravity gradient measurements, and other areas.