Fabrication and Characterization of an MOEMS Gyroscope Based on Photonic Bandgap Materials

This paper focuses on a micro-optoelectromechanical vibratory gyroscope that provides an optical output and operates in a resonant condition. A custom fabrication technology, based on a silicon-on-insulator substrate, has been considered for the development of the inertial sensor. The optical readout has been accomplished using a metal-dielectric multilayer photonic bandgap (PBG) material. Such an optical structure, composed of alternated layers of one metal and one dielectric material, is embedded in the micromachined device, thus obtaining reflection properties correlated with the displacement of the proof mass induced by the external angular velocity. The principle of the micromachined gyroscope is first introduced, and then, the microelectromechanical gyroscope structure, the materials properties, and the fabrication technology are illustrated. Numerical analyses have also been performed in order to gain insight into the micromachined device. Furthermore, the optical transduction principle that exploits metal-dielectric 1-D PBG structures has been investigated from both a theoretical and an experimental point of view.