【作者】 陈艳；

【导师】 杨志林；

【作者基本信息】 厦门大学 ， 光学， 2020， 博士

【摘要】 自从21世纪初首个GHz(微波)波段的超材料问世以来,超材料目前已发展成一个涉及物理学、材料学、生物医学以及光信息学等多学科交叉的前沿学科,近年来超材料己成为国内外学术界以及产业界的研究热点并受到持续广泛的关注。鉴于表面等离激元共振(Surface Plasmon Resonance,SPR)所能带来的优异光学特性,最初人们普遍将SPR与超材料结合起来构成表面等离激元超材料用于光学器件的设计与制作,这样的光学器件能够克服衍射极限,在亚波长尺度上实现光的产生、传输以及调制等。表面等离激元材料具有的不可避免的欧姆损耗严重制约了超材料在光学器件方面的进一步应用。为了避免金属带来的较大损耗,研究者们对超材料的研究逐渐从金属超材料过渡到了介质超材料。实际上金属和介质有其各自的优缺点,合理地设计金属-介质复合结构的超材料会整合提升体系的优点同时克服其缺点。这将为超材料的进一步发展应用带来新的突破。本论文采取理论分析与数值模拟相结合的方式展开研究,全文共分为六个部分。第一章绪论部分系统地介绍了表面等离激元和超材料的相关理论、应用以及最新进展,并在此基础上提出本论文的主要设想与研究思路。第二章重点介绍了本论文所用到的相关理论及数值计算方法。第三章利用金属-介质核壳单纳米粒子实现了可见光宽波段的远场定向散射及近场能量分布的调控;并进一步利用核壳纳米粒子链状结构实现了从可见光-近红外超宽波段的定向散射。第四章设计了一种基于全介质的二维纳米粒子阵列结构在可见光-近红外波段内实现了波长选择的完美反射与完美透射的超表面。第五章设计了一种基于金属-介质复合结构的超材料,实现了可见光-近红外波段的多窄带完美吸收。第六章,全文总结与展望。本论文工作的主要工作及创新点如下:(1)利用基于金属-介质核壳单纳米粒子实现了可见光宽波段的远场定向散射及近场能量分布的调控。在波长535-675nm范围内获得了 140nm宽波段的定向前向散射,另外,可以将“热点”调控在Au核表面、Cu2O壳层表面或同时存在于两者表面。并进一步利用核壳纳米粒子链状结构来提高定向散射的方向性,同时将定向散射的波长范围进一步拓宽,实现了从可见光-近红外超宽波段的定向散射。本工作为未来光学芯片的广泛应用以及高灵敏度光谱在纳米尺度上的应用提供重要的理论支撑。(2)设计了一种基于全介质的二维纳米粒子阵列结构在可见光-近红外波段内实现了波长选择的完美反射与完美透射的超表面。该超表面结构可在945-1020nm的波段范围内实现98%以上的完美透射,在668-780nm的波段范围内实现98%以上的完美反射,且在670-770nm波段范围内平均反射率超过了99%。进一步通过改变超表面的结构参数,在可见光-近红外波段范围内对实现完美反射与完美透射的位置进行了调谐。我们设计的超表面在宽带滤波器、彩色打印以及平板显示等领域有着巨大的潜力。(3)设计了一种基于金属-介质复合结构的超材料,通过结合介质材料Mie共振模式的窄带宽和金属材料具有固有损耗的特点,实现了可见光-近红外波段的多窄带完美吸收,且吸收率最高可达到99.8%。并且通过改变结构的周期,实现对吸收峰的位置和个数进行调谐。另外,将介质的Mie共振模式与金属的PSP模式耦合所带来的超窄半峰宽用于折射率传感,并对其性能进行了评估,最高的FOM值可达到133.3 RIU-1。我们设计的该种超材料在窄带滤波器、分光镜以及红外传感器等领域有着极大的应用前景。更多还原

【Abstract】 Since the first GHz(microwave)frequency band of metamaterials was successfully implemented in the early 21st century,metamaterials have developed into a interdisciplinary frontier discipline involving physics,materials science,biomedicine and optical informatics.In recent years,metamaterials have become a research hotspot in the academic and industrial circles at home and abroad,and have received sustained and extensive attention.Initially,surface plasmons and metamaterials are commonly combined to form surface plasmons metamaterials which are used in the design and fabrication of optical devices in view of the excellent optical properties of surface plasmon resonance(SPR).This metamaterial can overcome the diffraction limit and realize the generation,transmission and modulation of light at the sub-wavelength scale.However,the inevitable ohmic loss of surface plasmon materials has seriously restricted the further application of metamaterials in optical devices.In order to avoid the large loss caused by metals,researchers have gradually transferred the research of metamaterials from metal metamaterials to dielectric metamaterials.In fact,metals and dielectrics have their own advantages and disadvantages,so the reasonable design of metamaterials of metal-dielectric composite structure will integrate and lifting advantages of the system and overcome its disadvantages.This will bring new breakthrough for the further development and application of metamaterials.In this paper,theoretical analysis and numerical simulation are combined to carry out the research,and the full text is divided into six chapters.In the first chapter,induces the theory,application and latest development of surface plasmons(SPs)and metamaterials.On this basis,the purposes and main tasks of this thesis were proposed.In the second chapter,the related theories and numerical methods used in this work were basically described.In the third chapter,the metal-dielectric core-shell single nanoparticles are used to realize far-field broadband directional scattering in the visible light and the near-field energy distribution control.And further,the core-shell nanoparticles chain structure is used to realize ultra-broadband directional scattering from the visible light to the near-infrared.In the fourth chapter,a two-dimensional nano-array structure based on all dielectric is designed to realize the perfect reflection and transmission of wavelength selection in visible and near-infrared wave band.In fifth chapter,a kind of metamaterial based on metal-dielectric composite structure is designed to realize the perfect absorption of multi-narrowband in visible and near-infrared wave band.The sixth chapter is the summary and prospect of this thesis.The main contents and highlights are listed as follows:(1)The far-field broadband directional scattering in the visible light and near-field energy distribution control are realized by using metal-dielectric core-shell single nanoparticles.At the range of 535-675 nm,a wide spectrum range of 140 nm directional forward scattering was obtained.In addition,the "hot spots" can be controllably among the Au core surface,the Cu2O shell surface,or both.Furthermore,the core-shell nanoparticle chain structure is used to improve the directivity of the directional scattering,and the bandwidth of the directional scattering is further broadened to realize the ultra-broadband directional scattering from the visible to near-infrared.This work may provide important theoretical support for the wide application of optical chips in the future and the application of high sensitivity spectroscopy in nanoscale.(2)The metasurface base on all dielectric two-dimensional nanoparticle array structure is designed to achieve the perfect reflection and transmission of in the visible and near-infrared wave band.The results show that the metasurface structure can achieve more than 98%perfect transmission in the wavelength range of 945-1020nm,and achieve more than 98%perfect reflection in the wavelength range of 668-780nm,and the average reflectivity is more than 99%in the wavelength range of 670-770nm.The super surface base on all dielectric two-dimensional nanoparticle array structure is designed to achieve the perfect reflection and transmission of in the visible and near-infrared wave band.The results show that the super surface structure can achieve more than 98%perfect transmission in the wavelength range of 945-1020nm,and achieve more than 98%perfect reflection in the wavelength range of 668-780nm,and the average reflectivity is more than 99%in the wavelength range of 670-770nm.Furthermore,by changing the structure parameters of the metasurface,the wavelength of perfect reflection and transmission is tuned in the visible and near-infrared wave band.The metasurfaces which we designed have great potential in the fields of broadband filter,color printing and flat-panel displays.(3)A kind of metamaterial based on metal-dielectric composite structure is designed.By combining the narrow bandwidth of Mie resonant mode of dielectric material and the inherent loss of metal material,the multi-narrowband perfect absorption in visible and near infrared band is realized,and the highest absorption rate can reach 99.8%.By changing the period of the structure,the position and number of absorption peaks can be tuned.In addition,the ultra-narrow half peak width caused by the coupling of Mie resonant mode and metal PSP mode is used for refractive index sensing,and its performance is evaluated.The highest FOM value can reach 133.3RIU-1.The metamaterials which we designed have great application prospects in the fields of narrow-band filters,spectroscopes and infrared sensors.更多还原