High-performance light transmission based on graphene plasmonic waveguides

Abstract

Deep-subwavelength optical field localization and ultra-long-range transmission are crucial for nanoscale photonics integration. However, the transmission performances of plasmon modes are restricted by the trade-off between the modal confinement and loss. Here we design a graphene-coated nanowire-based plasmonic waveguide to achieve unprecedented optical waveguiding performances, which is fully compatible with the silicon-on-insulator platform. The graphene plasmon modes in the proposed structure are systematically evaluated in terms of geometric and physical parameters. Benefiting from the distinctive modal field distribution caused by the silicon nano-rib, the proposed graphene plasmonic waveguide could support a deep-subwavelength plasmon mode with ultra-low loss, which outperforms most graphene-coated nanowire-based waveguides in the mid-infrared band. Also, the modal properties are quite robust against fabrication imperfections and the proposed configuration exhibits very low mode crosstalk. The proposed waveguiding approach paves the way for potential applications in tunable integrated photonic devices at the nanoscale.