Figure 4
From: Hybridization of graphene-gold plasmons for active control of mid-infrared radiation
Design of hybridized gold-graphene metasurfaces for in-tune resonances. (a) Illustration of the metasurface’s cross-section. The parameters of the periodic array (top view shown in Fig. 2a) are ax = 1600 nm, ay = 110 nm, cx = 90 nm, cy = 100 nm. (b) Calculated reflectivity of the metasurface for three different values of graphene’s Fermi level, showing tunable symmetric and antisymmetric modes. The damping parameter of graphene is set to 13 meV (c) Reflectivity of the metasurface calculated for a larger range of graphene’s Fermi level. (d) Resonance peak for several Fermi levels. The minimum separation between the hybrid modes is at 0.18 eV, and corresponds to Δ = 23 meV. (e) Calculated near-field distribution of the gap-plasmons for EF = 0 eV and λ = 8.96 µm (left), EF = 0.40 eV and λ = 7.36 µm (center), and EF = 0.40 eV and λ = 9.60 µm (right). The field was calculated at the position x = 700 nm. (f) Calculated charge density map (arbitrary units) on the graphene plane for EF = 0.40 eV and λ = 7.36 µm (left), EF = 0.40 eV and λ = 9.60 µm (right). (g) Cross-section of the charge density along the y-axis at x = 650 nm for both the upper and lower modes.
