Abstract

We have used microwaves (6–20 GHz) to probe two-dimensional arrays of low-loss cylinders with a high dielectric constant (2 ≤ ε ≤ 9) between metal plates. With tegular arrays of a few hundred cylinders, we have observed transmission bands as well as photonic gaps. By. removing a few cylinders, localized defect states are observed. When the array is partly and randomly filled, transmission resonances occur that are identified with modes strongly localized in the Anderson sense. Confirmation of the strongly localized modes is established by spatial mapping of the electric-field pattern. Properties depending on the manner of excitation, dissipation, and array variabies will be presented. The conceptual connections with the theory of localization in two dimensions will be made.

© 1991 Optical Society of America