Fig. 1. Cross-section diagram of graphene-coated parallel dielectric nanowires

Fig. 2. (a) Real part and (b) imaginary part of the conductivity of graphene as functions of the operating frequency while the Fermi energies are 0.4, 0.5, 0.6 eV, respectively

Fig. 3. Field distributions of the six lowest order modes when f=51.579 THz, ρ=100 nm, d=50 nm, EF=0.5 eV. (a)~(f) are the longitudinal electric field distributions; (g)~(l) are the electric field intensity distributions

Fig. 4. Dependence of (a) effective refractive index and (b) propagation length on the operating frequency when ρ=100 nm, d= 50 nm, EF= 0.5 eV

Fig. 5. Distribution of the longitudinal electric field of mode 1 with the operating frequency of (a) 35 THz and (b) 55 THz

Fig. 6. Dependence of (a) effective refractive index and (b) propagation length on the spacing d when f= 51.579 THz, ρ=100 nm, EF=0.5 eV

Fig. 7. Distribution of the longitudinal electric field of mode 1 with the spacing d of (a) 10 nm, (b) 20 nm and (c) 75 nm

Fig. 8. Dependence of (a) effective refractive index and (b) propagation length on radius ρ when d=50 nm, f=51.579 THz, EF=0.5 eV

Fig. 9. Distribution of the longitudinal electric field of mode 1 when ρ=(a) 30 nm and (b) 80 nm, respectively

Fig. 10. Dependence of (a) effective refractive index and (b) propagation length on the Fermi energy EF when ρ=100 nm, d=50 nm, f=51.579 THz

Fig. 11. Distributions of the longitudinal electric field of mode 1 with the Fermi energy EF of (a) 0.4 eV and (b) 0.6 eV