Fig. 1. Schematic diagrams of the metasurface structure with optical thin film. (a) Section diagram of unit structure; (b) top view diagram of unit structure

Fig. 2. Phase change as a function of azimuthal angle of silicon nanobricks at the wavelength of 1530 nm

Fig. 3. Equivalent refractive index of metasurfaces

Fig. 4. Comparison of transmittance between optical antireflection coating system and single-layer metasurface equivalent thin film

Fig. 5. Light field distributions of metasurface lens at a wavelength of 1460 nm. (a) Without optical thin films; (b) attached with optical thin films

Fig. 6. Light field distributions of metasurface lens at a wavelength of 1530 nm. (a) Without optical thin films; (b) attached with optical thin films

Fig. 7. Light field distributions of metasurface lens at a wavelength of 1600 nm. (a) Without optical thin films; (b) attached with optical thin films

Fig. 8. Transmittance of metasurface lens with and without optical thin films at 1450-1600 nm wavelength

Fig. 9. Focusing efficiency of metasurface lens with and without optical thin films at different wavelengths