基于太极形介质柱六角光子晶体禁带特性研究

Photonic band gaps of two-dimensional hexagon-lattice photonic crystals based on Taiji-shaped dielectric rods

提出了一种新型的非对称性散射体的二维六角晶格光子晶体结构—–太极形介质柱光子晶体.利用平面波展开法从理论研究这种光子晶体结构的能带特性以及结构参数对完全禁带的影响.研究表明:散射体对称性的打破,TE模和TM模能带宽度和数目都会有所增加,有益于获得更宽的完全禁带以及更多条完全禁带.通过参数优化,发现在ε=17,R=0.38μm,r=0.36R,θ=0°时,获得最大完全带隙宽度0.0541(ωa/2πc);在ε=16,R=0.44,r=0.2R,θ=0°时,光子晶体完全带隙数目最多达到8条.

We present a novel structure of two-dimensional （2D） hexagon-lattice photonic crystal with asymmetrical scatterers-Taiji-shaped scatterers. The properties of photonic band gap （PBG） and the influence of parameter on absolute photonic band gap are analyzed by plane wave expansion method. The calculation results demonstrate that the reduction of scatterer symmetry can produce an increase in the number of PBG and a broadening of PBG width for both TE and TM model, which is conducive to obtaining wider and more absolute PBG. By optimizing the parameters of structure, we obtain the widest absolute PBG 0.0541（ωα/2πc） at ε=17,R=0.38μm,r=0.36R,θ=0° and the maximum of 8 absolute PBGs at ε = 16, R = 0.44, r = 0.2R, and θ = 0°.