LARGER ABSOLUTE BAND GAPS IN TWO-DIMENSIONAL PHOTONIC CRYSTALS FABRICATED BY A THREE-ORDER-EFFECT METHOD

In this paper, based on different influences of the lattice symmetry, the geometry of dielectric rod, and the structure of unit cell to absolute gaps we propose a so-called three-order-effect method for the construction of two-dimensional (2D) photonic crystals (PCs) with larger absolute gaps. As an example, by means of our approach we fabricate a 2D hexagonal lattice of cylinder with an optimal rod adding at the center of the unit cell, where the absolute gap is larger than that of the PC with similar structure studied by other group previously. On the other hand, we also find that many of the 2D PCs with larger absolute gaps reported previously possess optimal first-order and second-order substructures. Our three-order-effect method would be useful for the design of 2D PCs with larger absolute gaps.