Low-energy high-speed graphene modulator for on-chip communication

Abstract

In this work, we have proposed two different designs to improve the efficiency of a graphene-based electro-absorption modulator. The efficiency of the modulator is enhanced by increasing the overlap between the graphene layer and the optical mode of the waveguide. This is achieved by introducing the graphene layer between the silicon nitride cap and silicon waveguide. Using a single monolayer graphene configuration, a switching energy of 3.22 fJ/bit and maximum operating bandwidth of 10.89 GHz is achieved whereas the double monolayer graphene configuration allowed us to achieve a switching energy of 4.26 fJ/bit with a large operating bandwidth of 34 GHz at λ=1550 nm. Low energy consumption coupled with high bandwidth makes these modulator designs a potential candidate for use in on-chip optical communication.