NUMERICAL-ANALYSIS OF EIGENMODES LOCALIZED AT LINE DEFECTS IN PHOTONIC LATTICES

We calculated the eigenfrequencies and eigenfunctions of localized ele ctromagnetic modes brought about by line defects introduced into two-d imensional photonic lattices by means of the numerical simulation of t heir excitation process by a virtual oscillating dipole moment. In add ition to quite excellent agreement with the experimental result by Lin et al. [Appl. Phys. Lett. 68, 3233 (1996)], we showed that the observ ed localized mode has B-2 spatial symmetry. We also obtained the dispe rsion relation of the one-dimensional impurity band, which can be easi ly compared with experiments.