Slow-Light Dispersion in One-Dimensional Photonic Crystal Racetrack Ring Resonator

A one-dimensional photonic crystal racetrack ring resonator coupling with an optimized bus waveguide on a silicon-on-insulator wafer is proposed and demonstrated. The nonuniform free spectral range is realized in the resonator. A maximum group index of 37.6 and a slowdown factor of 11 are obtained. The nonuniform free spectral range and large group index are attributed to the slow-light effect near the band edge of the one-dimensional photonic crystal. A three-dimensional finite-difference time-domain method is performed to simulate the resonator. The simulation results show good agreement with the experimental results. The photonic crystal racetrack ring resonator demonstrated here will be beneficial for channel drop filters, wavelength-division multiplexing, lasers, and other applications.