Design and fabrication of multilayer-driven optomechanical device for force and vibration sensing

Multilayer structures are commonly used components in optics and photonics due to their unique properties to manipulate the spectral response of light. Multilayer-driven components for sensing purposes can bring some advantages such as high sensitivity, fast signal response, electromagnetic interference immunity, and low power consumption. Thus, a mechanically coupled optical system can be the right candidate for force and vibration detection. In this work, we propose and demonstrate an optomechanical sensing system for pressure and vibration detection using two multilayer structures, a circular membrane, a light source, and a photodiode. The design of this proposed system consists of two parts, which are optical design and mechanical design. In the optical design, we modeled the optical response of the multilayer structures in the visible spectra using the Transfer Matrix Method. The mechanical response, on the other hand, is calculated using finite element simulations via the COMSOL Multiphysics software. The multilayer structures are fabricated by RF-Sputtering technique and then integrated through a 3D printed mechanical housing. The sensor characteristics (sensitivity and resonance frequency) are experimentally investigated by a static loading test and a transient response analysis. Results are shown that the sensor frequency around 510 Hz and the sensitivity of the sensor about 50 Pa.