Fig. 6: Linearly polarized propagating plane wave incident on a sphere with radius a = 50 nm of gold and of three hypothetical materials.

a Real part of polarizability of a sphere of radius a = 50 nm, from Mie theory of: Au and three hypothetical materials denoted as Au1, Au2 and Au3, whose refractive index real parts are equal to those of Au, but their imaginary parts are artificially set to: A half of Au imaginary part (Au1), the same as the real part (Au2), and zero (Au3). b Numerical results of ILF, \({F}_{z}^{I}\), on each of these spheres illuminated by a linearly polarized plane wave with amplitude E0 = 1. c Imaginary part of polarizability of the four spheres. d Numerical calculation of RLF, < Fz>, on each of these spheres under the same incident wave as in b