Fabry-Perot腔谐振对横电波激励下亚波长一维金属光栅的异常透射性的作用

Fabry-Perot resonance on extraordinary transmission through one-dimensional metallic gratings with sub-wavelength under transverse electric wave excitation

利用时域有限差分法,对横电波(TE波)激励带电介质的亚波长一维金属光栅的光场分布进行了模拟分析,发现TE波在所研究的模型下具有异常透射现象.探究其物理本质,确定类导模共振理论是第一个峰和第二个峰产生的主要原因.在此基础上,从麦克斯韦方程出发,通过有效折射率法,确定了类Fabry-Perot(F-P)腔谐振是产生第三个峰的主要原因.从而完善了TE波在所研究的模型下产生异常透射现象的物理本质.为进一步研究TE波异常透射性的物理本质提供了一种完整的理论依据.

The transmission distribution of transverse electric wave （ TE） through one-dimensional metallic gratings with sub-wavelenghth slits with dielectric added in different positions has been simulated by the FDTD （ finite difference time domain） method,the extraordinary transmission can be produced at several special wavelengths. The simulation shows that the guided-mode-like resonance theory is the main reason giving rise to the first peak and the second peak. Based on the guided-mode-like resonance theory,from the Maxwell’s equations,we nade sure that the Fabry Perot resonance is the main cause producing the third peak by the effective index mehod. In a word,the guided-mode resonance theory and the Fabry-Perot-like resonance reveal the physical nature of the extraordinary transmission phenomenon which provides a complete theoretical basis for further study of the extraordinary transmission phenomenon of TE-polarized wave.