超材料是一類人工材料,它經(jīng)過工程設計后可以產(chǎn)生某些在自然狀態(tài)下不會出現(xiàn)的特殊性質(zhì)。超材料通常用某些復合材料經(jīng)過精心設計成不同的結構單元后組裝而成,這些復合材料包括塑料和金屬,通常以周期性重復的方式進行組織,其尺寸通常小于所考慮的波長。超材料經(jīng)過精心設計通常能夠影響電磁波或聲波,而且超材料的這種影響方式在體材料中并不多見。超材料的折射率對于特定的波長可以為負值,因而這類材料也被稱之為負折射率超材料,這一特性引起了人們的廣泛關注。本文主要對超材料的一些新型結構進行研究,并探索具有負折射率的新型材料單元,以期在光譜范圍內(nèi)（特別是在可見光區(qū)）能獲得負的介電常數(shù)、磁導率或者折射率。論文的主要工作和研究成果如下:（1）提出了一類核-殼金屬介電結構,在可見光范圍內(nèi)具有各向同性負折射率。該結構由兩個納米球（核和殼）組成,本文中選擇的材料是木材、油和銀金屬。在這類結構中,發(fā)現(xiàn)油殼銀核、木殼銀核、銀殼木核和油殼木核在可見光下均展現(xiàn)出負折射率。油殼銀核納米顆粒在550nm-680nm波長范圍內(nèi)具有較高的透射率;換句話說,我們認為它對黃色和橙色透射率較高是可以作為濾波器應用的。對于木殼銀核納米顆粒,分析表明,... 

【文章來源】：華中師范大學湖北省 211工程院校 教育部直屬院校

【文章頁數(shù)】：115 頁

【學位級別】：博士

【文章目錄】：
摘要
Abstract
1 Introduction
    1.1 Light and color
    1.2 Metamaterials and its history
        1.2.1 Development of structured materials
        1.2.2 The history of metamaterials
        1.2.3 Effective parameters of metamaterials
        1.2.4 Wave Propagation in Left-Handed Media
        1.2.5 An early demonstration of negative refractive index metamaterial
    1.3 Latest advanced research in metamaterial
    1.4 Dissertation outline
2 Basic theories and experimental techniques
    2.1 The optical behavior of the fundamental constituents of metamaterials
        2.1.1 Optical materials and electronic structures
        2.1.2 Dielectric and optical properties
        2.1.3 Optical properties of metals
        2.1.4 Metal-dielectric composites
        2.1.5 Electric metamaterials
        2.1.6 Magnetic metamaterials
    2.2 Simulation tools and experiments techniques
    2.3 Experimental techniques for optical metamaterial
        2.3.1 Fabrication of 2D optical metamaterial
        2.3.2 Fabrication of 3D optical metamaterial
        2.3.3 Other techniques for 3D metal-dielectric structures
    2.4 Summary
3 Dielectric-Metal Nanoshell Plasmonic Metamaterial for Filtering and Protection
    3.1 Silver core covered with oil shell nanoparticles
    3.2 Wood shell coated silver core nanoparticles
    3.3 Silver shell coated wood core nanoparticles
    3.4 Oil shell coated wood core nanoparticles
    3.5 Summary
4 Metamaterials side of mercury metal at the visible light range
    4.1 Transmission, Reflectance and Absorption characteristics
    4.2 Effect of the radius of the nanowire on the behavior of the material
    4.4 Summary
5 Metamaterial properties of epoxy resins nanospheres at visible light
    5.1 Permittivity, permeability, and negative refractive index properties
    5.2 Transmission, Reflectance and Absorption characteristics
    5.3 Negative refractive index in nanoparticles layer at the visible
    5.4 Summary
6 Circular dichroism in a chiral metamaterial
    6.1 Some elements of stereochemistry
    6.2 Chiral metamaterial
    6.3 Chirality parameter and ellipticity
    6.4 Circular dichroism numerical simulation in a chiral metamaterial
    6.5 Summary
7 Conclusion and future work
References
Publications
Acknowledgements
Appendix



本文編號：3521938