Quality factor of micro-ring resonators: calculation method and experiment

A model for calculation of the loaded quality factor of a micro-ring resonator, which takes into account distributed coupling of the ring with a straight waveguide, has been developed. A numerical simulation of the loaded Q-factor was performed for micro-ring resonators with specified geometry and refractive index profiles. The modeling results were compared with experimental Q-factor values derived from the measured transmission characteristics of micro-ring resonators with various geometries. To the authors’ knowledge, the obtained satisfactory agreement between theoretical and experimental data has been demonstrated for the first time. This validates the proposed model and method for preliminary calculations and the design of high-Q micro-ring resonators.