Similarity of dielectric resonance, local field distribution, and optical response in fractal composites

We investigate the dielectric resonance, local field distribution and effective optical response in the fractal structured metallic-dielectric composites using the Green's function formalism. With the evolution of the fractal level, similarity of the density of states (DOS) of dielectric resonances appears due to the self-similar structure, as well as of the inverse participation ratio (IPR) (which is used to represent the localization of field) of local field, and the effective linear optical responses. For a self-similar defect, when the difference admittance ratio eta [=(epsilon(2)-epsilon(0))/(epsilon(1)-epsilon(0))]< 0 or eta > 1, DOS and IPR of the defect modes also exhibit the similarity or antisimilarity. However, for eta is an element of(-1,2), the spectra of DOS and IPR become more complicated as the defect modes overlap the original modes. Finally, the existence of the self-similar defect has no obvious influence on the effective optical responses.Physics, Condensed MatterSCI(E)6ARTICLE6null7