次波長太極結構的漩渦狀能量流分析

Abstract

在東方的文化裡，太極圖案是一種具有互補性的特殊結構。在本文中，先利用電子束微影技術在玻璃基板上製作70x70個直徑為500 nm、厚度為30 nm與週期為700 nm的黃金太極陣列，並且使用有限元素分析法和傅立葉轉換光譜儀研究正向入射情況下，太極結構的穿透光譜，實驗與模擬非常的吻合，我們發現由於太極圖案的特殊結構，可以在近場區域產生漩渦狀的能量流，並且不同入射光的偏振狀態下對應到漩渦狀能量流的流動方向也有所不同，我們也提出個物理模型來解釋這特別的漩渦狀能量流。

The Taiji symbol is a very old schematic representation of two opposing but complementary patterns in oriental civilization. Using electron beam lithography, we fabricated an array of 70x70 gold Taiji marks with 30 nm thickness and a total area of 50x50 µm2 on a fused silica substrate. The diameter of each Taiji mark is 500 nm, while the period of the array is 700 nm. Here we present experimental as well as numerical simulation results pertaining to plasmonic resonances of several Taiji nano-structures under normal illumination. We have identified a Taiji structure with a particularly interesting vortex-like Poynting vector profile, which could be attributed to the special shape and dimensions of the Taiji symbol.