Fig. 1. Infrared permittivity obtained by FDTD fitting. (a) Au; (b) SiO₂

Fig. 2. Simulated results of infrared reflectance spectra of Au thin films with different thicknesses. (a) 0.05-0.15 μm; (b) 0.15-5 μm

Fig. 3. Simulated results of infrared reflectance spectra of SiO₂ thin films with different thicknesses. (a) 0.1-0.7 μm; (b) 0.1-5 μm

Fig. 4. Large-scale Au metamaterial structure. (a) Structural diagram; (b) simulation model

Fig. 5. Simulated results of infrared reflectance spectra. (a) A1-A4; (b) MM1 and MM2

Fig. 6. Electric field distributions at 8.8 μm. (a) Vertex scattering region A1; (b) edge scattering region A2

Fig. 7. Simulated and measured results. (a) Reflectance spectra; (b) MM1 and (c) MM2 captured by optical microscope

Fig. 8. Infrared emissivity performance comparison