表面電漿子是一種侷限在金屬和介質介面的與量子化電子振盪模式強烈耦合的電磁波。表面電漿子的低維特性及增強的介面電磁埸引發了各種十分有趣的新奇現象，同時造就了許多新穎的應用如以天文數字般增強的拉曼散射、異常的光通過奈米洞的傳輸、超越光波的繞射極限、改進的太陽能電池效能、微型奈米雷射等。然而，要調控和應用電漿子奈米材料的新穎特性，我們有必要徹底理解決定這些超穎材料物理性質的因子如大小、形狀、成分及環境等。因此，本計畫擬通過一系列的電磁理論模擬來探討多種奈米材料中表面電漿子相關現象的起因與機理。我們將依据所研究系統的特征，採用四種頻域的數值計算方法[格點電偶極近似法(DDA)、多層散射理論(layer KKR)、有限元近似法及平面波展開法]與一種時域的計算方法[即有限差分時域法(FDTD)]. 我們還將結合解析的理論方法如改進的長波近似法和異向電偶極模型對各種表面電漿子共振現象的新穎特性質作深入的分析。我們將和周遭的實驗同仁交流與合作、努力攻克奈米電漿子學中一些重要研究課題、共同培養奈米光電科技人才。 Surface plasmon polaritons (SPPs) are electromagnetic waves confined to a metal-dielectric interface and coupled to the quantized collective oscillation of free charge carriers. The low-dimension nature of SPPs and the strong electromagnetic field at the interface are responsible for a number of fascinating phenomena in fundamental science and exciting opportunities for technological applications such as enhancing Raman scattering by astronomical orders of magnitude, enabling extraordinary transmission of light through nanoholes, guiding electromagnetic waves with SPPs beyond the diffraction limit, developing new metamaterials with negative refraction , improving the efficiency of solar cells, and developing ultrasmall nanolasers. In order to manipulate the novel properties of plasmonic nanomaterials for various applications, we should thoroughly understand how the factors such as the shape, size, composition and environment of the structures control their physical properties. Therefore, the principal purpose of this proposal is to understand the origin and mechanism of the exciting surface plasmon-related phenomena in a range of metal nanomaterials. This will be achieved primarily by performing extensive numerical electromagnetic simulations. We will several complementary frequency-domain methods [e.g., the discrete dipole approximation (DDA), layer KKR, finite-element, and plane wave expansion methods] as well as the time-domain method [i.e., finite-difference time domain (FDTD) method)] that we have recently acquired, depending on the systems under consideration. Our numerical calculations will be complemented by such analytic theoretical techniques as the modified long wavelength approximation (MLWA) and anisotropic electric dipole model. We will also work closely with the experimental colleagues in Taiwan to tackle a few promising issues in nanoplasmonics and to strive to make some breakthroughs.