Figure 3: Retrieval results and surface current distributions of the shell.

(a) Retrieved permittivity, permeability and (b) index of the gold hemispherical shell. (c) Side-view (x-z plane) and (d) top-view (x-y plane) of surface currents on the shell. A current loop at the bottom in (c) suggests a negative magnetic dipole, m; meanwhile, surface currents along the edge of the shell in (d) induce a negative electric dipole, P.