Study Of Structure And Symmetry's Effect On Photonic Band Of 2-D Photonic Crystal

Photonic crystals are novel optical materials with the photonic band gap. Since photonic crystals can be integrated with semiconductor materials and technology perfectly, photonic crystals will have great application perspective in communication industry and optoelectronic integrated industry in the future. There is an extremely possibility for photonic crystals to be the essential material of photon industry in the future.The width of photonic band gap is an important aspect of photonic crystals' properties. People have been looking for new material and structure to obtain wider photonic band gap since the birth of photonic crystals. The theory calculation and numerical simulation of photonic bands not only explain the formation mechanism of photonic bands, but can also be used in instructing the experiment and study.The plane-wave expansion method was used to calculate TE and TM mode band gaps of hexagonal, circle, square scatterers in 2-D triangular and square lattices photonic crystals respectively. The co-effects of the shapes of Brillouin zone and scatterers to absolute band gaps were investigated. We found that for a given lattice symmetry, the size of the gap is the largest when the shape of the scatterer is the same as that of the lattice. The shape of Brillouin zone is hexagonal in the triangular lattice, at the same time the hexagonal scatterer photonic crystals get the widest absolute band gap. The square scatterer photonic crystals get the widest absolute band gap when the shape of Brillouin zone is square as it in square lattice.Also, the TE and TM mode band gaps for two-dimensional square lattice photonic crystal with hollow anisotropic tellurium (Te) rods with three different rotation operations were calculated. The effect of rotation on TE and TM mode band gaps and absolute band gap were investigated. The calculated results show high order band gaps of TM mode have a close relationship with structure rotation symmetry. The rotation symmetry and the distribution of Te in X-Y plane together influence TE mode band gaps.