提出由圆柱柱体粗细及介电常数差异间隔构成层状复合周期结构的二维光子晶体,用平面波展开方法数值研究其传输特性,数值结果表明,在不同二维圆柱半径层状复周期结构光子晶体透射谱中,禁带位置、宽度,传导模的出现与间隔层柱体的粗细差异有关,差异越大,光子禁带越小,中心频率位置向低频方向移动;在不同介电常数构成的层状复周期结构中,介电常数差异越大,光子禁带宽度越小,同样中心频率向低频方向移动;当间隔的层状柱体层数达到一定值时,没有传导模式出现,在相同差异条件下,禁带与传导模式相关,还与晶格结构的类型、电磁波入射面柱体的摆放顺序相关。相关结论为扩展二维光子晶体的应用提供新的理论依据。
Details on alternately layered composite cycle structure of two-dimensional photonic crystal, which was formed by the cylinder body thickness and dielectric constant difference, were discussed in the essay. Its transmission characteristics were studied numericaly by using the plane wave expansion method. The numerical results indicate that in the layered complex period photonic crystal transmission spectra with different two-dimensional cylindrical radius, the band gap position, width and conduction mode appearance associates with the differences of spacer columns thickness. The greater the difference is, the smaller the photonic band gap is, and the central frequency location moves to lower dielectric constant layer. Also, in different complex periodic structure, the greater the dielectric constant difference is, the smaller the photonic band gap width is. Likely, the center frequency moves to lower frequency. When the spacer column layer reaches a certain value, no conduction mode will exist. Under the same difference conditions, forbidden band not only associates with conduction mode, but also with the lattice structure type and the display order of electromagnetic wave incident surface column. The related conclusions can be applied to the expansion of two-dimensional photonic crystal applications as a new theoretical basis.