二维光子晶体禁带特性研究

采用平面波展开法对二维光子晶体分别在E和H极化下的带隙进行了计算. 考虑了填充比、晶格结构、介电常数对最大绝对帯隙的影响. 结果表明,不论是正方晶格还是三角晶格,TM模在介质柱型光子晶体中更容易形成带隙;TE模在空气孔型光子晶体中更容易形成带隙. 填充比一定,最大绝对帯隙宽度并非随着介电常数增大总是增大,而是存在一个峰值. 相对介电常数一定,最大绝对帯隙宽度随填充比的变化也存在一个峰值. 不论空气孔型还是介质柱型结构,三角晶格比正方晶格更容易形成帯隙. 关键词： 平面波展开法 TE模 TM模 最大绝对帯隙

Two-dimensional photonic crystal band gap characteristics

The plane wave expansion method is used to calculate the band gap of two-dimensional photonic crystal in the E and H polarization, with Taking into account the effects of filling ratio, lattice structure, and relative dielectric constant ratio on the maximum absolute band gap. The results show that either square or triangular array arrangement, it is easier for the dielectric cylinder type photonic crystal to form TM-polarized mode band gap; while, in the air-hole photonic crystal it is much easier to form TE-polarized-mode band gap. For a given filling ratio, with the increase of relative dielectric constant, the maximum gap width does not always increase, but it is peaked. Similarly, for a given relative dielectric constant, with the increase of filling ratio, it is also peaked for the maximum gap width. Moreover, no matter the erystal is air hole type or dielectric cylinder type in structure, the triangular lattice structure is much easier to form bands gap.