Exception for the zero-forward-scattering theory

Studies on single scattering of electromagnetic waves by magnetic particles were reported in the 1980s by Kerker et al. [J. Opt. Sec. Am. 73, 765 (1983)]. They obtained that very small spherical particles with electric permittivity and magnetic permeability values such that epsilon=(4-mu)/(2 mu+ 1) do not produce forward scattering. We show here that this condition contains an interesting exception at (epsilon=-2, mu=-2) when electric and magnetic resonances are present and around which the scattered field distribution is computed and described showing a polarization-insensitive behavior at the point (epsilon=-2, mu=-2). (C) 2008 Optical Society of America