Bandgap structure of optical Fibonacci lattices after light diffraction

The modification of the bandgap structure of optical Fibonacci lattices tha t arises from an increase in the system size is analyzed. It is found that there is a minimum critical size of the Fibonacci lattice necessary to form a photonic bandgap. The analysis of localized photonic modes of Fibonacci lattices shows that the removal of two layers of a lattice makes the lattic e mirror-symmetric. The "method of oblique bands" is developed to analyze t he bandgap structure of quasi-crystals. This method can also be applied to study two- and three-dimensional photonic and atomic quasi-crystals. (C) 20 01 MAIK "Nauka/Interperiodica".