Evolution of the complete photonic bandgap of two-dimensional photonic crystal.

In this paper, the complete photonic bandgap (CPBG) of two-dimensional photonic crystals (PCs), which are formed by a square array of solid or hollow dielectric rods connected with dielectric veins, are numerically investigated using the plane wave expansion method. It is clearly demonstrated how the CPBG evolves as the pattern of veins or the type of rods changes. An optimal structure with an ultralarge CPBG is found, whose CPBG reaches Δω=0.22374 (2πc/a), which is larger than those reported in literatures. The proposed structure seems to have promising applications due to its ultralarge CPBG and large fabrication tolerance.