雙負材料光子晶體之光學特性

Optical Properties of One-Dimensional Double-Negative Photonic Crystals

蘇怡恩(Su Yi-En)

指導教授 ： 吳謙讓

國立臺灣師範大學/科技與工程學院/光電工程研究所/碩士(2017年)

https://doi.org/10.6345/NTNU202201981

摘要

本論文探討的是一維光子晶體的吸收率。藉由TE波順向入射以及逆向入射光子晶體，比較順向與逆向的頻譜，進而找出共振點。
當順向與逆向在共振點的吸收率相差越多，具有單向性質，代表此共振點的效果越好。近年，含有雙負材料的光子晶體其光學特性格外受到重視，於是我們將研究包含此材料之光子晶體。本論文討論的光子晶體是由雙負材料與雙正材料規律排列所組成。每一章節將會在此光子晶體中加入不同的材料作為缺陷層，這些材料如下：雙負材料、雙正材料以及電單負材料。我們使用 Lorentz model 來表示雙負材料與電單負材料的介電常數與磁導率，並用轉移矩陣法來求得吸收率。觀察改變損耗或材料層數與厚度的光學特性。改變損耗、時，對圖形主要影響為。材料層數的多寡會改變吸收率，進而影響共振點的位置。根據改變不同材料厚度會造成圖形左移或右移。此研究一開始先討論由介電常數與磁導率區分的不同材料，接著將這些材料組成光子晶體，並利用數值方法分析不同條件時的光學特性，即可藉由控制這些條件調變光學特性。

關鍵字

光子晶體 ； 雙負材料 ； 吸收率

並列摘要

In this study, we discussed the one-way absorptance of a one-dimensional photonic crystal. To find the resonance point, we compared the spectrums of the TE wave forward and reversed incidence the photonic crystal. The more difference between absorptance of forward and reversed incidence at the resonance point means the better effect to it. In recent years, the optical properties of photonic crystals with double-negative (DNG) materials have received much attention, so in this study we focused on the photonic crystal which contained DNG material. The photonic crystal is composed of the double-negative and double-positive (DPS) materials with regular arrangement. In each chapter, we used different materials which were DNG, DPS and epsilon-negative (ENG) as a defect layer. We used Lorentz model to describe the permittivity and permeability of the DNG and ENG materials, and used Transfer Matrix Method (TMM) to calculate the absorptance. We observed the one-way absorptance of photonic crystal by changing the magnetic loss, electric loss, or the number and thickness of the layers. The effect of magnetic loss to the spectrum is much more obvious than that of electric loss. Numbers of the material layers would influence the absorptance and affect the position of resonance points. According to different thickness of the materials, the spectrum could be shifted to higher or lower frequency. We discussed the materials with different permittivity and permeability, and then reconstructed a photonic crystal with these materials. Furthermore, we calculated optical properties of the photonic crystal with numerical method under different circumstances, and could consequently modulate the optical properties of this photonic crystal.

並列關鍵字

Photonic Crystal ； Double-negative material ； Absorptance

參考文獻

[1] V.G. Veselago, “the electrodynamics of substances with simultaneously negative values of ε and μ”, Sov. Phys. Usp., 10, p. 509 (1968).

[2] R.A. Shelby, D.R. Smith, S. Schultz, “Experimental verification of a negative index of refraction”, Science, 292, p. 77 (2001).

[3] R.A. Shelby, D.R. Smith, S.C. Nemat-Nasser, S. Schultz, “Microwave transmission through a two-dimensional, isotropic, left-handed metamaterial”, Appl. Phys. Lett., 78, p. 489 (2001).

[4] D.R. Smith, W. Padilla, D.C. Vier, S.C. Nemat-Nasser, S. Schultz, “Composite Medium with Simultaneously Negative Permeability and Permittivity”, Phys. Rev. Lett., 84, p. 4184 (2000).

[5] L. Wu, S. He, L. Chen, “On unusual narrow transmission bands for a multi-layered periodic structure containing left-handed materials”, Opt. Exp., 11, p. 1283 (2003).