Fig. 1. Structural diagram of gold film circular hole array

Fig. 2. Transmission spectra when a₀=1000 nm, h=238.0 nm and R=234.0 nm. (a) Transmittance varying with wavelength; (b) reflectance, transmittance and absorptivity varying with wavelength around wavelength of 367.5 nm

Fig. 3. Transmittance varying with R and h

Fig. 4. Distribution of E_y in x-y plane at different z₁. (a) 400 nm; (b) 300 nm; (c) 200 nm; (d) 100 nm; (e) 0; (f) -100 nm; (g) -200 nm; (h) -300 nm; (i) -400 nm

Fig. 5. Distribution of E_y in single circular hole on x-z plane (y=0) with different h corresponding to maximum transmittance when R=234.0 nm. (a) h=119.0 nm,λ=560.0 nm, S₂₁=0.8022; (b) h=238.0 nm,λ=367.5 nm, S₂₁=0.8960; (c) h=476.0 nm,λ=393.0 nm, S₂₁=0.8467; (d) h=952.0 nm,λ=482.2 nm, S₂₁=0.7597; (e) h=1428.0 nm,λ=509.7 nm, S₂₁=0.7560; (f) h=1904.0 nm,λ=525.0 nm, S₂₁=0.8002; (g) h=2380.0 nm,λ=561.0 nm, S₂₁=0.6490; (h) h=2856.0 nm,λ=562.8 nm, S₂₁=0.6315

Fig. 6. Phase varying with wavelength

Fig. 7. Different electric fields varying with r

Fig. 8. Coupling efficiency ρ of Gauss mode and EH₁₁ mode. (a) ρ varying with w when t=0, R=234.0 nm; (b) ρ varying with t when R=234.0 nm, w=175.0 nm

Fig. 9. Dispersion curves of different modes

Fig. 10. Transmittance of circular hole array varying with wavelength after filling medium

Fig. 11. E_y distribution on different planes in terahertz band. (a) On x-y plane (z=0); (b) on x-z plane (y=0)