Fig. 1. Schematic of dielectric-coated metallic hollow waveguide. (a) Cross section; (b) structure diagram

Fig. 2. Relative permittivity of Ag

Fig. 3. Loss spectra of fundamental mode in circular waveguides and standard rectangular waveguides in G-band

Fig. 4. Loss spectra of TE₁₁ mode in circular waveguides with different dielectric layer thicknesses

Fig. 5. Electric field distributions of modes in waveguide. (a)(b) TE₁₁ mode; (c)(d) TM₁₁ mode; (e)(f) TE₁₂ mode

Fig. 6. Maximum coupling efficiency of modes with Gaussian beam and the waveguides with different dielectric layer thicknesses

Fig. 7. Dispersion spectra of fundamental mode for waveguides with different dielectric layer thicknesses

Fig. 8. Zero dispersion frequency of fundamental mode for waveguides with different dielectric layer thicknesses

Fig. 9. Comparision of waveguide dispersion characteristics before and after compensation in different frequency bands. (a) Nearly-zero dispersion-flattened scheme; (b) low additional loss scheme

Fig. 10. Variation trend of energy concentration ratio E_c and loss α with dielectric layer thicknesses

Fig. 11. Variation trend of power concentration ratio P_c and dispersion coefficient D with dielectric layer thicknesses