以散射矩陣法研究三維奈米金屬球之表面電漿共振

Abstract

本文介紹表面電漿之基本電磁理論，並使用散射矩陣法探討三維奈米金屬球中的表面電漿共振行為。我們針對單顆、二顆以及鏈狀金屬球陣列所組成的系統，討論表面電漿的震盪耦合現象。在材料參數方面，探討由理論模型以及實驗結果所得到的介電常數對表面電漿的影響。由模擬結果，可以得到表面電漿共振波長隨著金屬球尺寸及排列間距有所變化。除此之外，電磁波的極化決定了電漿的振動方向，進而影響了電場的增強效應。最後，在鏈狀陣列上觀察到電磁波能量在陣列上傳遞，進而達到波導的功能。

In this thesis we theoretically investigate the surface plasmon resonance in metal nanoparticles. We use the multiple scattering method to simulate the electromagnetc propagation and surface plasmon behaviors in particle systems. By this method, the fundamental resonance modes can be clearly resolved. We consider the permittivity functions obtained from the Drude model, experimental results and modification of the size effect. The simulations show that the surface plasmon resonance is greatly influenced by the particle size and arrangement. The enormous field enhancement due to surface plasmon coupling between particles is reported. The interparticle distance and the wave polarization are responsible for the large field magnitude. Finally, we study the plasmon resonance for chains of particles aligned in the polarization and propagating directions. We show the propagation of electromagnetic energy in the chains. These results may improve the development of plasmonic devices.