Compact multimode silicon-nitride waveguide micro-ring resonator with high-Q

A high Q racetrack micro-ring resonator (MRR) with ultralow propagation loss silicon-nitride waveguide is demonstrated by shaping the mode using a uniform multimode structure. They MRR is fabricated by the widely used LAT process. Results show that the Q factor of the specially designed MRR is significantly increased to more than 5 times higher order and reached 10.3 million for the first time.