Localized defect modes in finite metallic two-dimensional photonic crystals

Abstract

We present a comprehensive analysis of localized defect modes in finite photonic crystals with an isolated defect by means of the multiple-scattering theory. The scattering cross section of such systems can show resonance peaks owing to the tunneling through the defect, from which the eigenfrequency, eigenfunction, irreducible representation, and quality factor of the corresponding defect modes are obtained. The method, which is first applied to two-dimensional photonic crystals composed of dielectric cylinders, shows a fairly good agreement with known results obtained by the other methods. The method is also applied to clusters consisting of Drude-type metallic cylinders in a square configuration, where the eigenfrequencies of the localized modes are predicted as a function of the radius of the defect cylinder.