A Proposal for an Ultracompact Single-Layer MOEMS Accelerometer Based on Evanescent Coupling between Parallel Silicon Nanowaveguides

This paper proposes a novel MOEMS accelerometer based on evanescent coupling between parallel silicon nanowaveguides with the sub-wavelength gap. When input acceleration occurs, the coupling length between nanowaveguide on the proof mass with the one on the fame changes, leading to a reasonable variation in coupling efficiency. As a result, the input acceleration can be obtained by measuring the total transmission of nanowaveguides. Geometrical architecture of nanowaveguides is investigated in theory as well. Optical sensitivity of 23.78%/μm within measurement range of ±11.63g is obtained. Benefitting from compact structure of nanowaveguides, optical measurement on one single-layer structure becomes possible. This design shows high compactness with no need of assembly, suggesting the great potential of the proposed accelerometer in applications such as integrated inertial sensors.