Multimode Slot-Waveguide Sensor Using TE/TM Polarizations for Enhanced Sensitivity

This study investigates the adoption of a different structure to serve as the platform for Multimode Interference sensing, the slot-waveguide. A Si\(_3\)N\(_4\) slot-waveguide on a SiO\(_2\) substrate is numerically modeled, and a demonstration is presented on how the low-index guiding mechanism allied with a careful selection of the propagating modes can be used for sensitivity enhancement. Optimized devices presented bulk sensitivities per sensor length up to 3.43 rad\(\cdot \) RIU\(^{-1} \cdot \)\(\mu \)m\(^{-1}\) (for 633 nm wavelength of operation), that when compared to the highest sensitivity MMI sensors in the literature represented roughly a 90% enhancement.
Source: Sensing and Imaging - Category: Biomedical Engineering Source Type: research