Fig. 1. Structural diagram of waveguide

Fig. 2. Normalized electric field intensity distributions of fundamental mode when μ_c=0.5 eV,f₀=30 THz,and R=10 nm. (a) Under θ=π/6, G_gap=2 nm; (b) under θ=π/2, G_gap=2 nm;(c) under θ =π/6, G_gap=10 nm; (d) under θ=π/2, G_gap=10 nm; normalized electric field intensity distributions along (e) x and (f) y directions

Fig. 3. Modal properties versus gap when μ_c=0.5 eV,f₀=30 THz, R=10 nm, and θ=π/2. (a) Re(n_eff); (b) propagation length; (c) normalized mode area

Fig. 4. Modal properties versus θ when μ_c=0.5 eV,f₀=30 THz, G_gap=2 nm, and R=10 nm. (a) Re(n_eff); (b) propagation length; (c) normalized mode area

Fig. 5. Modal properties with respect to R when μ_c=0.5 eV,f₀=30 THz,G_gap=2 nm,and θ=π/3. (a) Re(n_eff), (b) propagation length; (c) normalized mode area

Fig. 6. Modal properties versus frequency under different chemical potential values when G_gap=2 nm, θ=π/3,and R=10 nm. (a) Re(n_eff); (b) propagation length; (c) normalized mode area