Absolute photonic band gaps in a two-dimensional triangular-lattice photonic crystal with dielectric rods

摘要

Absolute band gap of a two-dimensional triangular-lattice photonic crystal are calculated with the finite-difference time-domain method in this paper. Through calculating the band structures of the triangular-lattice photonic crystal consisting of rods with different shapes, it is found that the triangular rod can open a large band gap. A large absolute band gap of 0.066 (2πc/a) can be obtained for the structures with a triangular lattice of hollow triangular Ge rods immersed in air, corresponding to 14% of the middle frequency.