“…At present, silicon on insulator (SOI) [24,25] , organic polymer [26] and silicon nitride (Si3N4) [27,28] are the main materials for preparing micro ring resonators. Among them, SOI has large refractive index difference of core cladding (Δn=1.97), leading to the reduction of the waveguide mode field size but the higher coupling loss between the waveguide and the fiber; Organic polymer materials have low cost and simple preparation process.…”