Photonic band gaps tuned by atomic configurations in binary-compound photonic crystals

We report photonic crystals with two different rod atoms in the unit cell, the relative configuration of which is carefully regulated to optimize the photonic band structures (two-dimensional binary-compound photonic crystals). The photonic band gaps between any bands are found to be tuned by introducing the second atom at an appropriate position in the unit cell. In particular, by elaborately searching for the optimal position of the second atom, we can determine the atomic configurations that maximize the photonic band gaps.