利用全矢量的三维时域有限差分法,分析了一种金属银复合结构的反常透射增强效应.该结构是在一层打有六角排列的圆孔阵列的金属银层的上方放置一层六角排列的银圆环阵列构成.与普通的单层银打孔阵列相比，该结构明显具有更高的透射峰值和更窄的透射带宽.系统分析了结构的场强分布、坡印廷矢量能流分布图、透射峰的频率色散关系，结果表明该复合结构激发的更强的独特的表面等离激元模式主导了整个透射过程.

Using full-vectorial, three dimensional, finite difference time domain (FDTD) simulator, greatly enhanced extraordinary optical transmission (EOT) is studied in a composite metal system, which is constructed by stacking a hexangular annular ring array over a hexangular hole array, perforated in a metallic film. In comparison with conventional periodic hole array, perforated in a single metal film, the composite metal system exhibits much stronger transmission amplitude and narrower band width. Such a novel behavior of EOT is well explained by the numerical results obtained from the distributions of electric field intensity, flowing maps of Poynting vectors and frequency dispersions. The results show that strongly excited surface plasmon polaritons (SPP) plays a dominant role in coupling light throughout the composite system.