FIG. 5: 3 D isoline representation of the electromagnetic energy density (arb. units) in the far- field zone kr ≫ 1. This figure shows the difference in the far-field energy distribution that exists between the S and the P polarization planes, and the presence of an important backscattering effect in the P plane. Additionally, the tip of the metallic cone is drawn in blue. The sphere at the tip apex corresponds to the (unknown) near-fied zone where the far-field divergent energy distribution ∝ 1 r 2 is no longer valid. 20