Modification of photonic band structure in an ordered polystyrene particle layer by controlling interparticle light-mode interaction

Abstract

Optical spectra of self-assembled monolayers of polystyrene particles (LATEX) which possess quasi-two-dimensional photonic band (PB) structure are investigated in case of the variation of the ratio of the particle diameter to the interparticle distance by reducing the particle size in the layer with use of a reactive ion etching (RIE) method. The transmission spectra of oblique incidence with an s- or p-polarized light beam clearly show that the resonance of PB at k=0 is blue-shifted and the PB width gradually decreases as the particle size decreases down to a certain size. The characteristic behavior of the PB is qualitatively explained in the framework of tight-binding approximation where the interparticle light-mode interaction can be controlled by the magnitude of the overlapping of surface near-fields of Mie resonance modes for the individual particles. Further reduction of the particle size causes anomalous change in the PB branches around the crossing points with a folded optical branch in hexagonal empty lattice.