含二維金屬孔洞陣列之反射式遠紅外窄頻吸收器之研究

Abstract

本論文研究含二維金屬孔洞陣列的金屬-介電質-金屬型微共振腔於遠紅外波段的吸收特性與物理機制。我們模擬正方形孔洞陣列與兩種多邊形(凹與凸)孔洞陣列的吸收頻譜。與正方形孔洞相比，凹(凸)多邊形孔洞可增強S ( P )偏振電磁波的共振吸收。透過表面電流分析，我們發現凹多邊形孔洞提供兩個相互耦合的共振模態。藉由改變週期影響電流分佈，特定模態的吸收強度可有三倍以上的提升，並透過實驗驗證這些特性。

This thesis studies far infrared absorption properties and physical mechanism of metal-insulator-metal microcavities with two-dimensional metallic hole array. We calculate absorption spectra for microcavities with arrays of square holes and two types of polygon holes(convex and concave). Compared with square holes, the concave(convex) polygon holes exhibit enhanced resonant absorption for S(P)-polarized wave. The concave polygon holes provide two coupled resonant modes, which is revealed through surface current analysis. A threefold absorbance improvement for one of the resonances is obtained by modifying surface current distribution, achieved by changing array periodicity, and is verified experimentally.