Capacitive actuation and switching of add–drop graphene-silicon micro-ring filters

We propose and experimentally demonstrate capacitive actuation of a graphene–silicon micro-ring add/drop filter. The mechanism is based on a silicon–SiO2–graphene capacitor on top of the ring waveguide. We show the capacitive actuation of the add/drop functionality by a voltage-driven change of the graphene optical absorption. The proposed capacitive solution overcomes the need for continuous heating to keep tuned the filter’s in/out resonance and therefore eliminates “in operation” energy consumption.