Structural design and simulation of a micro-gyroscope based on nano-grating detection

The central concept underpinning the operation of the micro-gyroscope is the detection of the weak Coriolis force. We describe in detail the working principle of an optical micro-gyroscope based on nano-grating detection. A double-layer reflective metal nano-grating is used to detect the Coriolis force acting on the gyroscope. To analyze its structural sensitivity, a simulation model of the gyroscope is configured, results from which show that the structure achieves good modal matching and a structural sensitivity of 6.402 nm/°/s. Furthermore, the structure of the nano-grating is analyzed in an optical simulation, and a tolerance analysis is performed of several structural parameters to gain insight into realizing an actual device. Finally, a model of the gyroscope system was implemented in the SIMULINK environment. Using parameter values obtained from calculations, simulations of the nano-grating gyroscope gave a total sensitivity of 3.03 mv/°/s, along with a theoretical noise floor of 5.95 × 10−5°/s/√Hz. This confirms that the proposed optical micro-gyroscope performs well as designed.