Structural design and simulation of a MOEMS gyroscope based on subwavelength grating detection

A novel, to the best of our knowledge, out-of-plane microelectromechanical system (MOEMS) gyroscope based on Wood's type anomaly utilizing a subwavelength grating pair has been proposed. Based on this anomalous diffraction phenomenon, tiny changes in the displacement of the nanostructured grating elements lead to a dramatic increase or decrease of the optical diffraction amplitude. With this special feature, this structure is ideal to measure the weak Coriolis force of an MOEMS gyroscope. A simulation model of the gyroscope has been developed, with results indicating that the structure achieves good modal matching and a structural sensitivity of 0.094 nm/°/s. Optimal parameters for the subwavelength grating pair are determined through optimization design, and a tolerance analysis is conducted on several grating parameters, resulting in an optical diffraction sensitivity of 10.4%/nm. Finally, a model of the MOEMS gyroscope system was implemented in the Simulink module. Utilizing parameter values obtained from calculations, simulations of the subwavelength grating-based gyroscope yielded a total sensitivity of 3.04 mV/°/s and a theoretical noise floor of 5.1×10^-5°/s/H z. These results provide a theoretical foundation for the design and fabrication of an MOEMS gyroscope featuring subwavelength gratings.