OPTICAL-PROPERTIES OF 2-DIMENSIONAL AND 3-DIMENSIONAL INHOMOGENEOUS-MEDIA - A RENORMALIZATION APPROACH

The authors propose a position space renormalization group approach based on the Kadanoff block method, for the calculation of an effective dielectric function of cermet-type films (3D) or island films (2D). These models have been applied to simulated lattices and to digitized transmission electron micrographs of 2D and 3D systems. The results account for both the resonant absorption and the optical crossover corresponding to the metal-to-non-metal transition. The effective dielectric function is in very good quantitative agreement with most of the experimental data, even near the percolation threshold where it is found to obey scaling laws with critical exponents very close to the theoretical values.