奈米柱狀金屬共振腔對於光吸收的設計與應用

Abstract

奈米尺度下的金屬共振腔可以在入射光波時達到有效的抗反射。利用圓柱狀的金屬共振腔結構可以使光在腔體內形成共振，增強強度並且大幅降低光的反射量，同時能允許大的入射角度。本篇論文利用 RSoft 以及 COMSOL 兩套模擬軟體針對此種圓柱狀共振腔進行研究，發現在不同的幾何尺寸與材料下可以在反射頻譜上形成多個峰值，分別對應到不同的共振模態，並且在不同模態之下對光反射效率以及容忍入射角度都不同，本篇論文針對不同模態共振，設計出了反射效率可達 ，並且入射容忍角度可達 。本篇論文還針對此種共振腔進行了兩種應用的設計探討：光學折射率感測器以及太陽能用途之抗反射結構，在光學感測器方面更設計出可以使用多種感測方法的結構。

Nanocavities in metals have been demonstrated to act as efficient anti-reflection devices. Cylindrical cavities in a metallic substrate can form good optical resonators for enhancing the light intensity and reducing the reflection greatly in a wide range of angles of incidence. In this thesis, the simulation tools, RSoft and COMSOL, are used for the analysis of the resonant modes in the nano-cylinder resonators. It is observed that several peaks in the reflection spectrum can be obtained for the nano-cylinder resonators of different sizes as well as filled with different materials. Different resonant modes exhibit different reflection levels and allow different incident angles. In this thesis, nano-cylinder resonators can be used as highly-sensitive optical sensors and as potential anti-reflection devices for solar-cells. Key word: metal resonator、optical sensor、solar cell、antireflection structure、Rigorous Coupled-Wave Analysis、Finite Element Method.