Figure 20.

(a) silver nanodisks (small blue spots) deposited on dielectric (${\mathrm{CeO}}_2,n=2.3$) cuboids (dark red) which are placed on silver substrate (blue); (b) Raman enhancement G as function of wavenumber; (c) distribution of local electric field $|E/E_0|$ around silver nanodisk with a wavelength of the incident light of $\lambda =785$nm. Geometric parameters: elementary sell sizes are $D_x=650$ nm and $D_y=550$nm (light blue in (a); cuboid dimensions are $d_x=585$nm, $d_y=495$ nm, and height $h=47$ nm (dark red), diameter of silver nanodisk $d_c=21$ nm and heght $h_c=3$ nm, aspect ratio of the nanodisk $h_c/d_c=1/7$, distance between nanodisks $\approx 60$nm (from [17]).