一维金属光栅的透射光学特性

利用时域有限差分法模拟了一维金属光栅的透射光场的分布及光栅厚度等因素对透射光谱的影响.结果表明:特定波长的光通过金属光栅中的亚波长狭缝时有异常大的透过率增强.分析其物理起源,认为是类FabryPerot(FP)腔作用的结果.基底介电常量对类FP腔长度的调制导致了对透射光谱的影响.金属光栅表面激发的表面等离子体激元波与多缝干涉一样,对透射光谱有一定的影响,但不是形成增强的原因 关键词： 金属光栅 透射光学特性

Optical transmission properties of one-dimensional metallic gratings

We have simulated the transmission distribution of light through one|dimensional metallic gratings with subwavelenght slits and the effect of thickness of gratings on spectra. The result shows that unusual high transmission appears on spectra at several special wavelengths. We think that the high transmission is due to the effect of Fabry|Perot|like resonance. The permittivity of the substrate has an effect on transmission spectrum by modulating the length of Fabry|Perot|like cavity. The surface plasmon on the surface of gratings as well as the multi|slit interference does work on the spectra. But it is not the origin of high transmission.