Silicon nitride devices for visible and near-infrared refractive index sensing

Refractive index (RI) sensors based on silicon nitride on insulator (SiNOI) waveguide platform are designed and fabricated. SiNOI offers many advantages among which CMOS compatibility, low propagation losses, tolerance to temperature and fabrication variations as well as wide transparency range. The designed RI sensors include micro-ring resonators (MRRs), Mach-Zehnder Interferometers (MZIs) and loop-terminated MZIs (LT-MZIs) operating at both visible and near-infrared wavelengths. The sensors include strip and slot based sensing arms for chemical and biological sensing. These different components and the whole spectrum were designed and optimized using finite difference eigenmode (FDE) and finite difference time domain (FDTD) solvers. The sensors were fabricated using electron beam lithography in a SiN multi-project wafer (MPW).