The Mie formulation for homogeneous spheres is generalized to handle core–shell systems and multiple concentric layers in a manner that exploits an analogy with stratified planar systems, thereby allowing concentric multilayered structures to be treated as photonic bandgap materials. Representative results from a Mie code employing this analogy demonstrate that photonic bands are present for periodic concentric spheres, though not readily apparent in extinction spectra. Rather, the periodicity simply alters the scattering profile, which enhances the ratio of backscattering to forward scattering inside the bandgap, whereas modification of the interference structure is evident in extinction spectra in accordance with the optical theorem.
© 2002 Optical Society of America
(010.1110) Atmospheric and oceanic optics : Aerosols
(190.3970) Nonlinear optics : Microparticle nonlinear optics
(260.2110) Physical optics : Electromagnetic optics
(290.4020) Scattering : Mie theory
(310.6860) Thin films : Thin films, optical properties
David D. Smith and Kirk A. Fuller, "Photonic bandgaps in Mie scattering by concentrically stratified spheres," J. Opt. Soc. Am. B 19, 2449-2455 (2002)