Abstract

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 plane-wave expansion method. But Kuzmiak et al. showed that this method does not always give good convergence when the dielectric constant depends on frequency.¹ On the other hand, the present authors and his coworkers reported that the eigenfre-quencies and eigenfunctions of localized mid-gap modes originating from the defects in the photonic crystals can be calculated accurately by solving numerically the Max-well's equations with a virtual oscillating dipole moment embedded in the crystals as a source term.^2,3 In this paper, we will 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.

© 1998 Optical Society of America