The plane-wave scattering properties of a sphere of material having an ideal, homogeneous, and causal permittivity ε(f), and permeability μ(f) were investigated through detailed three-dimensional finite-difference time-domain, method-of-moments, and series-solution simulations. A Lorentzian functional form was chosen for ε(f) and μ(f), as it yields causal responses and allows us to study the physics of the left-handed-medium (LHM) regime. Our interest lies mainly in the frequency range where negative refraction [Re(n)<0] is observed. We found that when operating in the LHM regime, an impedance-matched sphere responds with scattering features strikingly different from those found in ordinary materials. In particular, we found zero backscattering and forward scattering that exceeds that of a metal sphere of similar size. The equality of <i>E</i>- and <i>H</i>-plane patterns was proved analytically and numerically, and the possibility of internal subwavelength focusing with a zero index sphere is also reported.
© 2004 Optical Society of America
(260.1960) Physical optics : Diffraction theory
(260.2110) Physical optics : Electromagnetic optics
(290.0290) Scattering : Scattering
(290.1350) Scattering : Backscattering
(290.4020) Scattering : Mie theory
Cesar Monzon, Donald W. Forester, and Louis N. Medgyesi-Mitschang, "Scattering properties of an impedance-matched, ideal, homogeneous, causal “left-handed” sphere," J. Opt. Soc. Am. A 21, 2311-2319 (2004)