▎ 摘　　要

A novel type of plasmonic waveguide, consisting of graphene-coated nanowire integrated with triangle wedge substrate and the low-index dielectric gap, is introduced for nanoscale field confinement. Numerical simulations indicate that extremely compact light confinement and low propagation loss can be obtained owing to the strong coupling between the graphene-coated nanowire and the tip of the triangle wedge substrate. Meanwhile, the proposed waveguide is quite tolerant to practical fabrication error for other geometry parameters. The graphene-based waveguide in this study is a natural extension of dielectric waveguide, and may be helpful to the studies and applications of nanoscale optical devices such as photonic integrated circuits and biosensors.