Design and demonstration of ultra-high-Q silicon microring resonator based on a multi-mode ridge waveguide.

We present the design and experimental demonstration of the ultra-high-Q-factor silicon microring resonator based on a multi-mode ridge waveguide. The multi-mode ridge waveguide is designed to decrease the propagation loss and to improve the Q factor. The ultra-high Q factor of 1.1×106 is experimentally demonstrated, with the free spectrum range of 0.208 nm. The single-mode ridge waveguide is used in the coupling region to reduce the dimension of the microring resonator, and the bend radius is only 20 μm. To precisely control the resonance wavelength, a small heater is implemented on the silicon microring resonator with the tuning efficiency of 7.1  pm/mW. The degenerate four-wave mixing of the silicon microring resonator is investigated, and the conversion efficiency is measured to be -15.5  dB without optimizing the dispersion of the microring resonator and carriers extraction.