介電質及金屬多層結構光學濾波器設計與分析

Abstract

光子晶體是一種不同折射率材料呈週期性排列的光學介質結構，經由模擬設計，可以實現調控電磁波的傳導來符合需求。在本篇論文中，共研究了兩個主題。

第一個是利用轉移矩陣法（TMM）來設計出以矽為基板的抗反射層（ARC），此ARC主要的波段為可見光到紅外線的範圍，力圖將反射率降至最低，提升整體的效率。經由不同的角度來觀察 TE、TM模式下的反射光譜。

第二個主題是利用金屬與介電質材料來設計出光學量子井（PQW）結構，我們分析銀、鋁、銅這三種金屬是否皆具有量子井的特性，結構上都以反對稱結構(AB)^m(MC)^n(AB)^m 為主，A=B=C=介電質，M=金屬，量子井的特性是可做為多通道的濾波器，可藉由調控缺陷的週期來實現，並在最後的分析找出濾波器的工作頻段。Photonic crystals, artificially periodic layered structures, have attracted much attention in the past two decades in the photonic community. In this thesis, based on the use of photonic crystal structures, we propose two filter structures which could be of technical use in photonic applications.

The first part is to exploit the transfer matrix method（TMM）to design and simulate the filtering properties of antireflection coating (ARC) on silicon substrate. We have made several analyses on the three-layer and four-layer ARC structures. The ARC filter is designed to be suitable from visible to infrared. It is designed to have the lowest reflectivity in a wider frequency range. The angular dependence of antireflection for both TE and TM modes is also given.

The second subject is to design a multichannel filter. We employ the photonic quantum well (PQW) structure made of dielectric and metallic materials. Three different metals, silver (Ag), aluminum (Al), and copper (Cu), will be used to comparatively study. In this study, asymmetric PQW structure, (AB)^m(MC)^n(AB)^m , is considered in our design. Here, layers of A, B, and C are dielectric slabs and M is a slab of metal. It is found that the number of channels is equal to the number of periods of central PQW. The proposed multichannel filter can be operated in the UV range.