異常增強穿透金屬孔洞陣列的物理機制及其應用之研究

Abstract

異常增強穿透金屬孔洞陣列的物理機制及其應用之研究 Key words: 表面電漿子、電漿子學、光子能帶、THz 通訊系統、生物化學 感測器 電漿子光學將成為未來整合於奈米等級下的電子及光子元件電路系統的重 要途徑而目前其相關的物理機制及應用發展卻仍尚屬研究初期。自從1998 年Ebbesen et al量測發現於可見光波段區的電磁波通過次波長金屬孔洞陣列 後，在某些特定波長具有異常的穿透率，相關的理論及實驗探討其根本之物 理機制及特性應用持續熱絡不已。然而，迄今此特異增強穿透值的根本之物 理機制解釋仍舊頗受爭議，而且金屬孔洞陣列的設計參數與量測結果的光學 特性的相關性仍尚待開發。因此，在這計畫裡，我們計畫研究光與表面電漿 子透過不同的金屬孔洞陣列下的互動，探討光學穿透特性與不同的設計參數 的關係，並且設計應用於THz 通訊系統下所需之光通道濾波器及於生物化 學分子感測系統的光波導耦合表面電漿共振感測器。 藉由調整如孔洞大 小、形狀等等的設計參數，我們理論及實驗上驗證光學特性與這些設計參數 的關係式，並且研究探討譬如主要波長、頻寬等這些特定光學特性的主要影 響之物理機制。不僅如此，我們將進一步的應用這些發現及探討，設計具有 平坦通道及全方位化的新穎光通道濾波器以及整合奈米光子能帶結構及金 屬孔洞陣列設計高靈敏度的光波導耦合表面電漿共振感測器。

Plasmonics is expected to be a promising approach to achieve the integration of electronics and photonics at the nanoscales, and currently the research on plasmonics and its applications is developed in the early stage. Since in 1998 Ebbesen et al observed the extraordinary transmission through the sub-wavelength metallic hole arrays in the visible region, relevant theoretical and experimental studies on underlying physical mechanisms and potential applications have drawn tremendous attention. However, hitherto the explanation of this enhanced transmission is still controversial and relation between design parameters and optical properties remains undiscovered. In this project, we propose to study the interactions between lightwave and surface plamon polaritons through different metallic hole arrays, to discuss optical transmission properties with various design parameters, and to apply to the design of optical bandpass filters for THz communication systems and coupled waveguide-surface plasmon resonance sensors for biomolecular and chemical material sensings. By adjusting the design parameters, such as hole sizes, hole shapes, and so on, we theoretically and experimentally demonstrate the relation between optical properties and these design parameters, and investigate the primarily physical mechanisms of the specific optical properties, such as the center frequency and bandwidth of transmission spectrum. In addition, by applying this exploration, we design (omni-directional) bandpass filters with flat-top passband, and coupled waveguide-surface plasmon resonance sensors with the integration of a photonic bandgap structure in optical waveguide and the metallic hole arrays.