采用时域有限差分法(FDTD)对介质柱构成的8重准晶光子晶体(PQCs)的带隙特性进行了研究,分别讨论了介质柱形状和对称度变化对带隙宽度、带隙对方向不敏感特性的影响。数值模拟和分析结果表明,当填充因子保持不变时,介质柱形状不会影响带隙对方向不敏感的特性;六边形、正方形和三角形介质柱构成的准晶光子晶体的带隙宽度分别是圆形介质柱带隙宽度的98.9%,97.8%和91.5%,带隙宽度随着介质柱对称程度的降低逐渐变窄,但变化可以忽略;带隙宽度随介质柱的椭圆率,即对称度的降低而变窄,但变化趋势平缓,即使椭圆率小至0.3,相对带隙仍然有5.9%。这些分析结果表明,8重准晶光子晶体的带隙对加工误差所引起的形状变形和轴长偏离都具有较高的稳定性。

The effect of the cylinder shape and symmetry of two-dimensional 8-fold photonic quasicrystals (PQCs) is numerically investigated using the finite difference time domain (FDTD) method. Results indicate that,when the fill factor remains:i) the property that the bandgap is independent on the direction can be remained;ii) the lower the symmetry of the cylinder shape is,the narrower the bandgap of 8-fold PQCs is. The reduction of the band gap is negligibly small for the hexagon and square cylinder while it reduces more for the triangle cylinder;iii) the lower the symmetry of the ellipse cylinder shape is,the narrower the bandgap of 8-fold PQCs is. However,the variant of the bandgap is very gently.