Taming the Electromagnetic Boundaries via Metasurfaces: From Theory and Fabrication to Functional Devices

Figure 32

(a) Principle of the Huygens metasurface. The fields in regions I and II are defined independently of each other, and the surface equivalence principle is employed to find the fictitious electric and magnetic surface currents that satisfy the boundary conditions at the metasurfaces. (b) Simulated time snapshot of the magnetic field (Hz) of a -polarized plane wave, normally incident upon the designed Huygens’ surface. (c) Dimensions of the unit cells comprising Huygens’ metasurface. (d) SEM images of the optical Huygens’ surfaces. (e) Perspective view of an optically thin, isotropic Huygens’ metasurface that efficiently refracts a normally incident beam at telecommunication wavelengths. (f) Time snapshot of the steady-state, -polarized electric field when a plane wave is normally incident from the bottom at a wavelength of 1.5 μm. The incident electric field has an amplitude of 1 V/m. Figures are reproduced from [176, 181].

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