Numerical Investigation and Optimization of a Mechano-Optical Sensor based on a Grated Waveguide Optical Cavity

Recently we have proposed and demonstrated a novel and compact read-out principle for cantilever deflection with a grated waveguide optical cavity. The device, consisting of a microcantilever suspended above a Si3N4 grated waveguide (GWG), is a potentially highly sensitive mechano-optical sensor for gas sensing. In this report, we present results of a numerical investigation to optimize such an integrated GWG-cantilever platform using the bidirectional eigenmode propagation method. The results show that sensitivity of the device strongly depends on the grating depth, length of the grated section and the cantilever width.