2010-08-012024-05-17https://scholars.lib.ntu.edu.tw/handle/123456789/691157摘要：金屬奈米粒子在適當波長之光波照射下，可產生表面電漿波動，其對應之能量子稱為侷域性表面電漿子。此種表面波動現象常導致極大之局部電場強度，而有許多奈米光子學上的應用，故近年來甚受研究者重視。相較於單一金屬奈米粒子，群聚之多個金屬奈米粒子的表面電漿效應顯然更複雜，有待進一步深入研究。本計畫擬發展一簡化之邊界積分方程法以計算多個金屬奈米粒子之電磁場分佈，探討此多體系統之表面電漿子對近場與遠場之效應。所謂簡化之邊界積分方程法係指在準靜態近似下，將邊界上之等效面電流與面磁流集中到每一金屬奈米粒子表面上的六個點，以減少未知變數之個數，但仍大致保有積分方程的準確性的優點。吾人先在少數個金屬奈米粒子的特例下，藉商用軟體驗證本方法之準確度，接著再大量計算多個金屬奈米粒子的電磁場分佈，以探討多個金屬奈米粒子系統中的表面電漿子的物理特性。本計畫的理論與模擬除有助於瞭解多個金屬奈米粒子系統之表面電漿子理論外，更可拓展其在奈米光子學上的應用。<br> Abstract: By illumination of light at a proper wavelength, the surface plasma wave can be induced on the surface of a metallic nanoparticle. The corresponding energy quantum is called the localized surface plasmon. The concomitant localized high electric field intensity may lead to applications in nanophotonics. Therefore, the study on surface plasmons has become an important research topic recently. The surface plasmon effect of a swarm of metallic nanoparticles is apparently more complicated than that of a single nanoparticle, and deserves further investigation. In this proposal, we develop a simplified boundary integral-equation method to numerically compute the electromagnetic field distribution of multiple metallic nanoparticles for investigating the effects of surface plasmons on the near field and the far field. For the simplified boundary integral-equation method, the equivalent surface electric and magnetic currents on the boundary surfaces are, under the quasi-static approximation, assumed to exist only at six points on the surface of each metallic nanoparticle. This approximation can reduce the number of unknown variables, but may still take some advantage of the accuracy of an integral-equation method. The accuracy of our numerical method is verified by commercial software COMSOL in the special case of several metallic nanoparticles. Then the electromagnetic field distribution of a large number of metallic nanoparticles is computed for studying the physical characteristics of the associated surface plasmons. The theoretical and simulated results from this project will be helpful in understanding the theory of surface plasmons in a system of multiple metallic nanoparticles and hence developing novel applications in nanophotonics.金屬奈米粒子表面電漿子數值模擬metallic nanoparticlessurface plasmonnumerical simulation