Light scattering from macroscopic spherical bodies. II. Reflectivity of light and electromagnetic localized state in a periodic monolayer of dielectric spheres

The optical reflectivity from a monolayer of regularly arrayed dielectric spheres is calculated. It is shown that the structures of the reflectivity curve are classified into three groups: a broad background, fine structures at the channel thresholds, and a group of sharp peaks. the first two groups are attributed to the interference effect in an effective slab and the resonance anomaly in the multichannel scattering, respectively. The third is found to arise due to coupling with new modes, electromagnetic localized states. They are induced by the two-dimensional translational symmetry of the system and they show interesting optical activities dependent upon the polarization as well as the wave vector of the incident light. The possibility of detecting them is discussed in relation to some actual systems.