厚度非次序之光子晶體光學性質之研究

Abstract

光子晶體是由不同折射率材料所構成的週期性結構. 隨著它們那令人感興趣及驚奇的電磁學性質, 光子晶體的研究在最近幾年一直是光子學熱門的項目. 在本篇論文中, 我們的研究題目是集中在於討論厚度非次序排列的光子晶體, 包括金屬-介電質光子晶體以及帶有缺陷部分的光子晶體. 而光子晶體最主要的特徵就是電磁波在其中行進需有一個頻率範圍, 稱為光子能隙(PBG). 而擁有光子能隙(PBG)的材料在光電子學以及光學通訊方面有很多有潛力的應用. 我們可以發現當厚度非次序排列應用在一維MDPC,DDPC時, 可以產生更寬的光子能隙(PBG). 而此光子晶體的厚度非次序排列可以藉由使用介質層厚度的數學分布來設計. 此外, 隨著厚度非次序分布程度以及週期數的改變, 更多的光學性質會被發現. 並且也可發現對於帶有缺陷部分的光子晶體而言, 藉由光子晶體的厚度非次序分布, 一些有關透射波峰的光學性質是可調的.

Photonic crystals (PCs) are periodic structures made of materials with different refractive indices. With their interesting and amazing electromagnetic properties, research on PCs continues to be a hot issue in photonics in recent years. In this thesis, our research topic has focused on the disordered PCs, including the metallic-dielectric PC (MDPC) and PCs with defect slabs. The main feature of PCs is that electromagnetic waves are prohibited to propagate within a certain frequency range called photonic band gap (PBG). Materials containing PBG have many potential applications in optoelectronics and optical communication. We found that the wider PBG can be obtained when the disorder is introduced in the one-dimensional (1D) MDPC, and dielectric-dielectric PC (DDPC). The disorder in a PC can be introduced and designed by making use of a certain statistical distribution of layer thicknesses, namely by adjusting the degree of disorder and number of periods. Other PBG properties of disordered PCs are found. For a PC with some defect slabs, the filtering properties and the number of transmission peaks can be tuned by introducing the disorder.