Molecular Coupling of Two Defective Photonic Modes in Two Dimensional Photonic Crystals

We investigate the coupling property of photonic molecular modes from two defects in two dimensional triangular photonic crystal. We obtain the relationship between the defect modes and its symmetry, and the coupling of the defect modes decreases with the increasing distance between the two defect cylinders. The frequencies of the local defect modes of lowest and highest frequency modes concentrate to the center of the defect modes fully.