Integrated Silicon Nitride Horizontal Long Period Grating for Refractometric Gas Sensing applications

We designed an integrated long period grating based on the horizontal periodic tapering of a silicon nitride channel waveguide. The structure is studied for gas sensing applications, using Styrene AcryloNitrile as sensitive layer. Simulation results from the proposed architecture show a high sensitivity beyond 1700 nm/RIU using a wavelength interrogation method centered at 1550 nm for a 20pm large and 300pm long structure.