Figure 3.

(a) Schematic configuration of nanodisk-based MM; Structural parameters are described. (b) Absolute value of H_z-field profile on resonance. It shows the generation of current loops (black arrows). The resonance conditions are as follow: λ = 879 nm, D = 130 nm, h = 30 nm, t = 30nm, P_x = 580 nm, P_y = 300 nm; (c) Schematic illustration of double-resonances gold nanodisk array substrate (left panel) and its SEM image (right panel); (d) SERS spectra on double-resonances. The diameter changes from 100 to 143 nm (black to purple); (e) Reflectance spectra corresponding to (d). Parts (c–e) are reprinted from Reference [87], with the permission of AIP Publishing.