異常光學穿透理論與應用之研究

Abstract

摘要 我們對於金屬週期孔洞結構的異常穿透行為進行了理論上的分析，並提出了此結構可能的應用。我們介紹了兩種處理金屬週期孔洞結構的計算方式，第一種是基底展開法，第二種是傅立葉模型法，本論文中詳列了這些方法計算式。在與我們現有的實驗資料比較下，我們所使用的計算結果與實驗非常吻合。這表示了我們的計算方法十分可信，適合去描述此物理系統的圖像。 理論分析的工作部分如下。第一，我們提供一個簡單的方法把費諾共振中的直接穿隧以及共振穿透兩成份給分離開來。第二，我們計算了不同大小的長方形以及十字架形週期孔洞的穿透頻譜，並針對頻譜隨孔洞形狀的演化做出解釋。第三，我們用傅立葉模型法分析了金屬的非完美效應。最後我們使用Fabry-Perot共振圖像去解釋當金屬孔洞之中有可傳遞的波導態時的穿透行為。 我們提出兩個金屬週期孔洞結構的應用方向。第一個是把非對稱十字架形的金屬孔洞結構做成光學補波片。第二個是使用金屬孔洞結構的表面強場去提升長波長偵測器的工作能力。

Abstract We theoretically analyze extraordinary optical transmission phenomena for metallic hole array structures, and propose some applications for the array structures. We introduce two calculation methods in this paper: one is basis expansion method, and the other is Fourier modal method. We give detail formulas for these two methods. The calculation results give good agreement with our experimental data. This indicates that our calculation is very reliable and is suitable for this array structure. We do the following works in this paper. First, we demonstrate a simply method to separate direct tunneling channel and resonant transmission channel in a Fano system. Second, we calculate the transmission spectra for rectangular hole arrays and crossed rectangular hole arrays of different sizes, and explain the evolution of the transmission spectra with the changing of the hole dimensions. Third, we use the Fourier modal method to analyze metal loss effects. Finally, we demonstrate that if the waveguide mode inside the hole is propagating, the transmission behavior can be explained by Fabry-Perot resonance. We propose two applications for metallic hole array structures. First, we show that asymmetric crossed rectangular hole structures can be used as the optical compensator. Second, we show that the strong near field of hole array structure can enhance the sensitivity for long wavelength optical detectors.