A parametrically excited MEMS gyroscope with optical readout: Design and simulation

Abstract

Design and simulation of a Micro-Opto-Electro-Mechanical (MOEMS) Gyroscope are presented. Compared to common gyroscopes, it features lower linear acceleration sensitivity and requires a lower drive voltage. The mechanical design ensures a high resonance frequency. It also has a smaller footprint and is insensitive to environmental variations. To improve shock resistance, four two-dimensional stoppers have been employed, which limit the gyroscope’s movement in two directions and increase the acceleration tolerance of the structure. Furthermore, an optical method is utilized to detect the gyroscope displacement such that the intensity of the output light is proportional to the displacement of the mechanical structure along the sense axis. A variable gap between two strip SOI waveguides modulates the output light intensity. The drive and sense mode resonance frequencies are obtained as $21.9\mathrm{kHz}$ and $22\mathrm{kHz}$ respectively; the measurement range is $\pm 50\mathrm{deg}/s$, the mechanical sensitivity is 0.56 $\frac{\mathrm{nm}}{\mathrm{deg}/s}$ and the overall sensitivity is $1.6\frac{\text{\%}}{\mathrm{deg}/s}$.