Dual-band optical filter based on a single microring resonator embedded with nanoholes

A dual-band optical filter based on a single microring resonator embedded with nanoholes is theoretically and experimentally demonstrated for the first time. A numerical model based on transfer matrix method is utilized to simulate the performance of this device. The coupling between the microring resonator and the Fabry-Pérot resonator formed by nanoholes gives rise to the dual-band optical filtering spectrum. In our experiment, a single microring resonator embedded with nanoholes was fabricated on a commercial 220-nm-thick-top-silicon silicon-on-insulator (SOI) platform. Good performance was achieved with measured extinction ratio of 9 dB, insertion loss of lower than 1 dB, and quality factor of 11900. Both experimental and simulation results are in good agreement.