Optical micro mechanical accelerometer with double grating: design and simulation

Abstract

A double-grating-based optical micro mechanical accelerometer with differential detection structure is reported in order to enhance the optical scale factor. A theoretical model is established based on the multi-slits Fraunhofer diffraction model. According to the calculation and analysis, the normalized optical scale factor is improved from 5.491E6 with the single-side detection structure to 10.98E6 with the differential detection structure. Mechanical sensitivity with 4.04 nm/g and natural frequency with 7756.8 Hz of the optical accelerometer are shown by finite element simulation. The results of simulations show a novel scheme for an optical micro mechanical accelerometer with high resolution, to the best of our knowledge. Furthermore, micro-opto-electro-mechanical system fabrication flow is given in this work, which provides a reference for other kinds of optical sensors.