Defect Modes in Two-Dimensional Triangular Photonic Crystals

We propose a simple method of making defects in two-dimensional photonic crystals by radius modification and analyzed energy levels of such defects obtained by the supercell method. In a triangular lattice of the semiconductor-rods-in-air structure, it was found that both a single sharp acceptor level and a single sharp donor level can be achieved with a defect bandwidth of about 5% of the band gap for E-polarized in-plane waves.