Mie scattering by concentric multilayers

Summary form only given. 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. This analogy enables core/shell and concentric multilayered structures to be treated as photonic bandgap (PBG) materials. In this case the PBG relates to spherical waves rather than plane waves. However there are important differences we discuss that may give these systems more design flexibility. In particular the decomposition of plane waves into superpositions of vector spherical harmonics provides an extra degree of freedom in dielectric structure design. We discuss methods for designing concentrically stratified particles to control the angular scattering profile, interference structure, and ripple structure of small particles. We show that large absorbing cores with quarter-wave dielectric shells result in PBGs in scattered light.