Figure 22.

(a) single elementary cell of metal-dielectric substrate with gold nanodisks (orange color) placed on each of dielectric cuboids (gray), geometrical parameters are: lattice unit dimensions of $D_x$ = 1634 nm, $D_y$ = 698 nm, dimensions of dielectric resonators are $d_{x1}=d_{x2}=704$ nm and $d_{y1}$ = 568 nm, $d_{y2}$ = 284 nm, height of the resonators is h = 148 nm. The parameters of the top gold disk are $d_c$ = 50 nm, aspect ratio $h_c/d_c=(1/14)$; (b) electric field enhancement $|E/E_0{|}^2$ as function of wavenumber; gold disks are placed in the center of the top surface of dielectric cuboids. (c) electric field distribution $|E/E_0|$ over the gold disk. The metasurface is illuminated by light with an amplitude $E_0$ and a wavelength of 785 nm, the light is incident normal to the metasurface (from [17]).