Modeling of Grating Assisted Hybrid Plasmonic Filter and Its On-Chip Gas Sensing Application

A dual-band stop vertical hybrid plasmonic filter based on the silicon nitride fin Bragg grating (FBG) is designed and simulated in the infra-red band. It consists of the two silicon nitride FBGs embedded in the silicon waveguide separated by L _SP spacing. Finite element method-based 3D-COMSOL simulation shows two stop band wavelengths at 1.462 and 1.515 μm, respectively. Furthermore, its on-chip methane gas sensing application for coal mines is also investigated. The proposed filter-cum-sensor is the complementary metal-oxide-semiconductor compatible demonstrating 856.50-nm/RIU sensitivity, 120-RIU ^-1 figure of merit, 6.34×10 ^-2 RIU limit of detection, and 0.52-nm/K temperature sensitivity.