New method to calculate photonic band structures with frequency-dependent dielectric constants

Summary form only given. Dispersion relations of photonic crystals with spatially periodic dielectric constants that do not depend on frequency have been calculated with sufficient accuracy by means of the plane-wave expansion method. But Kuzmiak et al. (1994) showed that this method does not always give good convergence when the dielectric constant depends on frequency. On the other hand, the present authors and his coworkers reported that the eigenfrequencies and eigenfunctions of localized mid-gap modes originating from the defects in the photonic crystals can be calculated accurately by solving numerically the Maxwell´s equations with a virtual oscillating dipole moment embedded in the crystals as a source term. In the paper, we extend this method to deal with regular crystals with frequency-dependent dielectric constants and apply it to a two-dimensional square lattice composed of metal cylinders.