Tunable spectral splitting in nanoscale graphene waveguide with coupled resonators

Abstract

We propose and investigate a graphene-based resonator-coupled waveguide system comprising input/output graphene sheet bus waveguides and two graphene nanoribbon (GNR) resonators for bandpass spectral splitting. The system is composed of two graphene sheet waveguides and two GNRs located at the same side of the waveguides with different distances. The coupling between two GNRs results in the electromagnetically induced transparency effect and the bandpass spectral splitting. Moreover, benefiting from the chemical-potential-dependent optical properties of graphene, both the spectral symmetry and operation frequency can be dynamically adjusted, separately. The structure can find potential applications for integrated tunable functional devices such as filters and modulators.