核-殼結(jié)構(gòu)納米線表面/界面的電磁散射研究
Electromagnetic scattering at surface/interface of Core-shell nanowires

15000字 38頁

目錄
目錄 1
摘要 2
Abstract 3
第1章 緒論 4
1.1 引言 4
1.2 納米線簡介 4
1.3納米線的光學性質(zhì) 5
1.3.1紫外-可見光吸收特性 5
1.3.2 光致發(fā)光 6
1.3.3 納米線光學性質(zhì)的研究方法簡介 8
1.4 光散射理論的發(fā)展簡介 10
第2章 光散射理論 12
2.1 引言 12
2.2 散射理論基礎(chǔ) 13
2.2.1麥克斯韋方程組 13
2.2.2 光波與介質(zhì)相互作用 14
2.2.3 散射相關(guān)的基本物理量 16
2.3 光散射理論 18
2.3.1 線性散射 18
2.3.2非線性散射 19
2.3.3 光散射理論的應(yīng)用 19
2.4 Mie 散射公式 21
2.4.1 光散射矢量波描述 21
2.4.2 球形顆粒Mie 散射公式 22
第3章 核殼結(jié)構(gòu)納米線的電磁散射 26
3.1 引言 26
3.2 核殼納米線的電磁散射研究 27
3.3 總結(jié) 32
致謝 33
參考文獻： 34


摘要
摘要 亞波長納米結(jié)構(gòu)中的光散射研究在許多領(lǐng)域有著重要應(yīng)用，如在光通信，氣象，傳感中的應(yīng)用，以及醫(yī)學和生物學等其他學科領(lǐng)域的研究。金屬核與高介電常數(shù)的殼組成的核殼結(jié)構(gòu)納米線因其特殊的結(jié)構(gòu)而具有特殊的光學和電學性質(zhì)，本文將主要研究核-殼結(jié)構(gòu)的納米線的電磁散射。
本文首先簡單的介紹了光散射的發(fā)展，核-殼結(jié)構(gòu)納米線的制備以及性質(zhì)等；介紹了納米線的光學性質(zhì)，包括納米線的紫外-可見光吸收特性，光致發(fā)光等。然后詳細介紹了光散射的基礎(chǔ)理論及基本原理。主要研究了垂直入射波下核-殼結(jié)構(gòu)納米線表面的電磁散射。對于p偏振光入射波下的納米線，每個電諧振對應(yīng)于兩個簡并散射波段，而磁諧振只對應(yīng)一個波段。因此，當電偶極子(ED)和磁偶極子(MD)被調(diào)諧到光譜重疊時，ED的幅度是MD的兩倍，產(chǎn)生了一對散射消失角。我們還進一步表明，納米線的散射特性是偏振相關(guān)的，并且散射消失角也是通過高階電動模式與寬MD模式的干擾而引起的Fano共振產(chǎn)生。
關(guān)鍵詞 核殼結(jié)構(gòu) 納米線 光散射 電磁散射



Abstract
Abstract Light scattering by subwavelength nanostructures play a fundamental role in many fields, such as optical communications, meteorology, sensing, medical and biological research, and other interdisciplinary fields. Core-shell nanowires consisting of metal core with a high dielectric constant shell posssess particular optical and electrical properties, duo to their special structure characteristics. In this work, we studied the scattering of (metal) core-shell (high-permittivity dielectric) nanowires, which support both electric and magnetic resonances.
At first，We briefly reviewed the development of light scattering, the preparation of core-shell nanowire structure and the properties of core-shell nanowires. We focus on the optical properties of nanowires, including ultraviolet-visible light absorption properties, photoluminescence behavior etc. Secondly, the thesis reviewed the basic principle and theory of light scattering. We study the scattering of normally incident waves by core-shell nanowires, which support both electric and magnetic resonances. Within such nanowires, for p-polarized incident waves, each electric resonance corresponds to two degenerate scattering channels while the magnetic resonance corresponds to only one channel. Consequently, when the electric dipole (ED) and magnetic dipole (MD) are tuned to overlap spectrally, the magnitude of the ED is twice that of the magnetic one, leading to a pair of angles of vanishing scattering. We further demonstrate that the scattering features of nanowires are polarization dependent, and vanishing scattering angles also can be induced by Fano resonances due to the interference of higher-order electric modes with the broad MD mode.


Key words core-shell, nanowires, scattering of light, electromagnetic scattering