Figure 2
From: Ultracompact Graphene-Assisted Tunable Waveguide Couplers with High Directivity and Mode Selectivity
Single group TE antenna coupler. (a) Perspective view of the proposed device for directional coupling y-polarized incident light into fundamental TE mode to the right port around 1.55 μm. (b) Cross-sectional view of the graphene-hybrid waveguide patterned with gold nanoantennas. Inset: System coordinates. (c) Ex distribution along the waveguide central plane at 1.55 μm. (d) Directivity as a function of antenna center-to-center distance along x axis. (e) Tunability analysis of the proposed device. (f) and (g) Corresponding center operation wavelength λd to (d) and (e) respectively. (h) Transmission rate of the waveguide ports under different incident polarization states. (i) Vector-graph of the electric field distribution at the right port. Inset: \(|{\bf{E}}|\) distribution details for the antennas along the graphene plane. (j) and (k) \(|{\bf{E}}|\) distributions for the right and left port respectively.
