Tunable, Fourth-Order Silicon Microring-Resonator Add-Drop Filters

We demonstrate the first tunable, high-order channel add-drop filters based on silicon microring resonators. They meet rigorous, telecom-grade spectral requirements for microphotonic R-OADMs (reconfigurable optical add-drop multiplexers). The design addresses 100GHz-spaced, 40GHz-wide channels over 16-32nm.