▎ 摘　　要

NOVELTY - The structure has a third layer hypersurface located below a first layer hypersurface and a second layer hypersurface. The first layer hypersurface, a second layer hypersurface, and a third layer hypersurface are provided with a rectangular array structure that is provided with multiple basic units. A first insulating layer surrounds the first hypersurface and the second hypersurface. A second insulating layer surrounds the third slayer hypersurface. A graphene structure layer and a substrate are respectively fixed on an upper surface of an insulator structure layer, where the refractive index of the second layer hypersurface is greater than the first insulating layer, and the refractive index of the third-layer meta surface is greater than the refractive index of the first substructure. USE - Graphene based three-layer over surface coupler structure. ADVANTAGE - The structure can adjust the beam propagation path and the effective refractive index of each layer through three super-surface layers, reduces the refractive index contrast of the first substructure and the third layer of the hypersurface, increases the working bandwidth of the coupler in an effective manner, so as to increase the coupling efficiency of the coupler. DESCRIPTION OF DRAWING(S) - The drawing shows a schematic view of a graphene based three-layer over surface coupler structure.