Дисертації з теми "Hyperbolic metamaterial"
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Wang, Xuan. "Fabrication, structural and optical study of self-assembled hyperbolic metamaterial." Thesis, Bordeaux, 2017. http://www.theses.fr/2017BORD0694/document.
Повний текст джерелаNovel optical properties in the visible range are foreseen when organizing nanoresonators, which can be performed by the self-assembly of plasmonic nanoparticles prepared by wet chemistry. In this project, we use templating block copolymers structures to organize plasmonic particles. Our goal is to relate the structure of the prepared nanocomposites thin films, and in particular the nature, density and spatial organization of the nanoparticles, with their optical index.For this purpose, we first fabricate lamellar superlattices of diblock copolymers (poly(styrene)-block-poly(2-vinylpyridine) of controlled thickness (100nm-700nm), controlled lamellar period size(17 nm-70 nm) and optimized alignment and homogeneity. Following the fabrication of the multilayer templates, an in situ and reproducible synthesis of metallic nanoparticles was developed in order to generate nanocomposites selectively inside the P2VP layers. The size of Au nanoparticles can be well controlled around 7-10 nm. We also found that the reduction process could influence the shape (sphere, triangle or cylinder) and size by using different solvents or reducing agents. Because the extraction of accurate optical responses from the spectroscopic ellipsometry data, which will come in the last part, critically relies on the precise knowledge of the sample structure. We have used several experimental techniques to access a precise description of the produced materials. In particular, we used a Quartz Crystal Microbalance as a measurement tool to ‘kinetically’ study the volume fraction of Au loading. We find that the amount of gold in the composite layers can be varied up to typically 40 volume%. The optical properties of the nanocomposite films are determined by variable angle spectroscopic ellipsometry and analyzed by appropriately developed effective medium models. The films are structurally uniaxial and homogeneous, and we can define their dielectric permittivity tensor with the ordinary (parallel to the substrate) and extraordinary (normal to the substrate) components. The analysis of the lamellar structures allows the extraction of the components εo and εe, both presenting a resonance close to =540nm, with a significantly stronger amplitude for εo. When the gold load is high enough and the couplings between particles are strong enough, the values of εo become negative close to the resonance, and the material reaches the so-called hyperbolic regime, which constitutes a step towards applications in hyper-resolution imaging
Habib, Md Samiul. "Sub-diffraction Imaging with Wire Array Metamaterial Fibres: Novel Geometrics and Migration of Artefacts." Thesis, The University of Sydney, 2018. http://hdl.handle.net/2123/18702.
Повний текст джерелаFullager, Daniel B. "Theory, Characterization and Applications of Infrared Hyperbolic Metamaterials." Thesis, The University of North Carolina at Charlotte, 2017. http://pqdtopen.proquest.com/#viewpdf?dispub=10267303.
Повний текст джерелаHyperbolic Metamaterials (HMMs) are engineered structures capable of supporting lightmatter interactions that are not normally observed in naturally occuring material systems. These unusual responses are enabled by an enhancement of the photonic density of states (PDOS) in the material. The PDOS enhancement is a result of deliberately introduced anisotropy via a permittivity sign-change in HMM structures which increases the number and frequency spread of possible wave vectors that propagate in the material. Subwavelength structural features allow effective medium theories to be invoked to construct the k-space isofrequency quadratic curves that, for HMMs, result in the k-space isofrequency contour transitioning from being a bounded surface to an unbounded one. Since the PDOS is the integral of the differential volume between k-space contours, unbounded manifolds lead to the implication of an infinite or otherwise drastically enhanced PDOS. Since stored heat can be thought of as a set of non-radiative electromagnetic modes, in this dissertation we demonstrate that HMMs provide an ideal platform to attempt to modify the thermal/IR emissivity of a material. We also show that HMMs provide a platform for broadband plasmonic sensing. The advent of commercial two photon polymerization tools has enabled the rapid production of nano- and microstructures which can be used as scaffolds for directive infrared scatterers. We describe how such directive components can be used to address thermal management needs in vacuum environments in order to maximize radiative thermal transfer. In this context, the fundamental limitations of enhanced spon- taneous emission due to conjugate impedance matched scatterers are also explored. The HMM/conjugate scatterer system’s performance is strongly correlated with the dielectric function of the negative permittivity component of the HMM. In order to fully understand the significance of these engineered materials, we examine in detail the electromagnetic response of one ternary material system, aluminium-doped zinc oxide (AZO), whose tuneable plasma frequency makes it ideal for HMM and thermal transfer applications. This study draws upon first principle calculations from the open literature utilizing a Hubbard-U corrected model for the non-local interaction of charge carriers in AZO crystalline systems. We present the first complete dielectric function of industrially produced AZO samples from DC to 30,000 cm –1 and conclude with an assessment of this material’s suitability fo the applications described.
Chen, Hongwei. "Directional Emission of Light in Hyperbolic Metamaterials and Its Application in Miniature Polarimeter." University of Dayton / OhioLINK, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=dayton1565630730775184.
Повний текст джерелаBrownless, John Scott. "Strips, Slabs, and Stacks: The Guided Modes of Conventional and Novel Wire Media Devices." Thesis, The University of Sydney, 2017. http://hdl.handle.net/2123/16522.
Повний текст джерелаRing, Josh. "Novel fabrication and testing of light confinement devices." Thesis, University of Manchester, 2016. https://www.research.manchester.ac.uk/portal/en/theses/novel-fabrication-and-testing-of-light-confinement-devices(51572720-0c49-482e-8523-e44ca877117f).html.
Повний текст джерелаMota, Achiles Fontana da. "Modeling and analysis of hyperbolic metamaterials for controlling the spontaneous emission rate and efficiency of quantum emitters." Universidade de São Paulo, 2019. http://www.teses.usp.br/teses/disponiveis/18/18155/tde-19032019-084555/.
Повний текст джерелаNos últimos anos, intensivo esforço tem sido devotado para o estudo de novas método para o controla da missão de fótons de emissores quânticos (EQs), especialmente para aplicações em telecomunicações. Estes métodos dependem da adaptação da radiação dos EQs, geralmente avaliadas por meio das bem conhecidas figuras de mérito, como o tempo de meia vida (τ) e a eficiência quântica (η). O controle da emissão de fótons é importante pois quanto mais rápido os fótons são emitidos, maior é o número de vezes que o EQ retorna ao seu estado excitado por segundo. Portanto, é crucial criar canais de decaimento adicionais para reduzir τ, o que necessariamente requer o aumento do fator de Purcell (P). Uma das abordagens mais promissoras para aumentar P envolve uma nova classe de metamateriais, conhecida como metamateriais hiperbólicos (MHs). Esta classe de materiais apresenta pronunciada anisotropia, onde os elementos paralelo e perpendicular do tensor de permissividade (em relação ao eixo de anisotropia) apresentam sinais opostos, resultando em uma superfície de isofrequência (SI) hiperboloidal aberta (IS). Essa forma incomum de SI leva à característica mais marcante dos MHs, a existência de modos fotônicos com número de onda (k) muito maior do que aqueles no espaço livre (k0), conhecidos como modos alto-k. Ao manipular esses modos, é possível manipular a densidade de estados fotônicos (DES) dos MHs, controlando assim os parâmetros de radiação do QE. A abordagem mais simples para a criação de MHs é por meio de uma pilha plana de camadas metálicas e dielétricas alternadas. Entretanto, a espessura finita dessas camadas induz a dispersão espacial, tornando a extração de parâmetros efetivos (homogeneização) destes meios uma tarefa desafiadora. Neste contexto, propomos nesta tese uma nova abordagem de recuperação de parâmetros constitutivos a dispersão espacial de todos os parâmetros eletromagnéticos do meio é levada em consideração. Nós demonstramos que a parte real da curva de dispersão se aplaina (correspondentemente com uma grande parte imaginária) devido à ausência de modos propagantes dentro do metamaterial. Esta região plana é fortemente dependente das espessuras das camadas e é uma manifestação direta da dispersão espacial Além disso, nós mostramos que se a dispersão espacial não for corretamente considerada no processo de homogeneização, o tempo de meia vida do EQ pode ser superestimado, o que é prejudicial para aplicações de telecomunicações. Além disso, demonstramos como melhorar P por um fator maior que 100 com o uso de MHs. a maior parte da potência dissipada pelos EQs são acopladas nos MHs como modos de alto-k (que não se propagam no espaço livre). Portanto, a energia é dissipada termicamente no interior do MH, resultando em uma redução de η. Alguns autores recorreram a MHs nano-estruturados (MHNE) para converter os modos alto-k em modos de espaço livre (k≤k0) visando o aumento de η. No entanto, muitos dos projetos do NPHM ainda dependem de simulações numéricas tridimensionais (3D) computacionalmente dispendiosas. Assim, também propomos nesta tese um novo método semi-analítico para modelar, tanto em duas como em três dimensões (2D e 3D, respectivamente), a emissão de radiação de EQs interagindo com estruturas nano-estruturadas. O baixo custo computacional deste método faz com que seja atrativo para o mapeamento de P e η em função da posição relativa do EQ e do MHNE. Esse mapeamento é uma ferramenta útil para entender o comportamento de decaimento de todo o sistema, já que os EQs são arbitrariamente distribuídos e orientados dentro do MHNE. A curva de decaimento calculada analiticamente permite que a eficiência quântica efetiva do sistema (ηeff) e o fator de Purcell (Peff) sejam obtidos diretamente, assumindo múltiplas fontes eletromagnéticas arbitrariamente distribuídas. Neste sentido, propomos aqui um novo procedimento para otimizar os parâmetros geométricos do MHNE visando a maximização de ηeff enquanto Peff é aumentado à um valor desejado. Aplicamos o modelo proposto a um MHNE composto por nove camadas de Ag/SiO2, com a camada de polímero embutida com Rodamina 6G, visando maximizar ηeff para um aumento de dez vezes de Peff. Este procedimento permitiu que o ηeff fosse incrementado em 69% e 170% para nano-estruturas uni e bidimensionais, respectivamente. Além disso, o tempo necessário para construir os mapas P e η (utilizados no cálculo da curva de decaimento) é reduzido em aproximadamente 96% quando comparado com os calculados numericamente via FDTD. Este procedimento abre caminho para o desenvolvimento de novas fontes de luz de alta velocidade e eficiência para aplicações de telecomunicações.
Omeis, Fatima. "Theorical and experimental study of plasmonic metamaterials for infrared application." Thesis, Université Clermont Auvergne (2017-2020), 2017. http://www.theses.fr/2017CLFAC041/document.
Повний текст джерелаThe control of light absorbance plays a fundamental role in today's photonic technologies. And the urge to design and develop flexible structures that can absorb electromagnetic waves is very growing these days. Usually, these absorbers relies on plasmonic resonances that arise in noble metals in the visible range. However, the extension of the plasmonic properties to the infrared and THz spectra requires adequate materials that have a metallic behavior at these frequencies. In this work, we study numerically and experimentally the metal-insulator-metal (MIM) structures realized from highly doped semiconductor Si:InAsSb that has a metallic behavior in the infrared range. In the second, part we improved the efficiency of the MIM resonators by using hyperbolic metamaterials that also miniaturize the resonators. In the last part, we propose an ultra-thin universal design that overcomes the material barrier so that the total absorption can be achieved for different spectral ranges without changing the material
Peillon, Etienne. "Simulation and analysis of sign-changing Maxwell’s equations in cold plasma." Electronic Thesis or Diss., Institut polytechnique de Paris, 2024. http://www.theses.fr/2024IPPAE004.
Повний текст джерелаNowadays, plasmas are mainly used for industrial purpose. One of the most frequently cited examples of industrial use is electric energy production via fusion nuclear reactors. Then, in order to contain plasma properly inside the reactor, a background magnetic field is imposed, and the density and temperature of the plasma must be precisely controlled. This is done by sending electromagnetic waves at specific frequencies and directions depending on the characteristics of the plasma.The first part of this PhD thesis consists in the study of the model of plasma in a strong background magnetic field, which corresponds to a hyperbolic metamaterial. The objective is to extend the existing results in 2D to the 3D-case and to derive a radiation condition. We introduce a splitting of the electric and magnetic fields resembling the usual TE and TM decomposition, then, it gives some results on the two resulting problems. The results are in a very partial state, and constitute a rough draft on the subject.The second part consists in the study of the degenerate PDE associated to the lower-hybrid resonant waves in plasma. The associated boundary-value problem is well-posed within a ``natural'' variational framework. However, this framework does not include the singular behavior presented by the physical solutions obtained via the limiting absorption principle. Notice that this singular behavior is important from the physical point of view since it induces the plasma heating mentioned before. One of the key results of this second part is the definition of a notion of weak jump through the interface inside the domain, which allows to characterize the decomposition of the limiting absorption solution into a regular and a singular parts
Ju, Nyan-Ping, and 朱念平. "Straight-sidewall cavity broadband hyperbolic metamaterial perfect absorber." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/55dyb6.
Повний текст джерела國立交通大學
電子工程學系 電子研究所
104
A new structure for a nearly-perfect hyperbolic meta-material(HMM) absorber is proposed, and initial experimental verification is provided. To date, HMM PMAs are realized using tapered stacks that can provide adiabatic waveguiding over a wide spectral range. Nevertheless, the tapered nature can prevent its usage for large-area applications such as the emitters in thermophotovoltaics (TPV). The design proposed here has decent wavelength scalability and can be used from optical black holes to microwave perfect absorbers. The physics behind the HMM straight-sidewall cavity is the broadband highly confined resonance. While, in most of the cases, the broadband quasi-guided modes are weekly confined in nature, the HMM cavity can provide broadband resonances but still maintain reasonably strong oscillation strength for high absorption. This is because the photonic density of state (PDOS) is boosted dramatically by the hyperbolic dispersion of the straight-sidewall Al/SiO2 stacks.
Tsai, Shang-Yi, and 蔡尚益. "Study on the Optical Coupling Characteristics of Nanowires Hyperbolic Metamaterial." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/yxj5c5.
Повний текст джерелаHuang, Jing-Hao, and 黃敬豪. "Surface Plasmon Enhanced Fluorescence by Silver Nanoparticle on Hyperbolic Metamaterial." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/3564dh.
Повний текст джерела國立臺灣海洋大學
光電科學研究所
107
Silver nanoparticles on hyperbolic metamaterial (HMM) fabricated by thermal deposition and sputter system respectively have been studied. Surface morphology and uniformity of the structure were observed by Atomic Force Microscope (AFM) and Scanning Electron Microscope (SEM). The light absorption band of the structure was measured by spectrometer. The influences of different SiO2 thickness between silver nanoparticles and hyperbolic metamaterial on Surface Enhanced Raman Spectroscopy (SERS) have been investigated. Afterwards, the samples were sputtered different thickness of SiO2 followed by thermal deposited Alq3 and DCJTB, respectively. The increasing intensity of Photoluminescence (PL) and the significantly decreased life time of Time-Resolved Photoluminescence (TRPL) were observed.
Wang, Szu-Hao, and 王思皓. "Metal Enhanced Fluorescence by using silver nanoparticles decorated hyperbolic metamaterial substrate." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/70752550761423500707.
Повний текст джерела國立臺灣海洋大學
光電科學研究所
103
The main goal of this thesis is to explore the hyperbolic metamaterial multi-layer structure for fluorescence enhancementof CdSe / ZnS quantum dots (CdSe / ZnS Core-Shell Quantum Dot) and fluorescent dye(DCJTB).We put different nanoparticles:silver nanoparticles/nanostars on multi-layers substrate to probe the influence of nanoparticles on the photoluminescence and time-resolved photoluminescence of quantum dots and DCJTB. We used D.C.sputter to manufacture the Si-Ag multi-layers and we found that quantum dots on multi-layers,the PL intensity of quantum dotson multi-layersis enhanced approximately 3.051 times than that on glass substrate. After spreading silver nanoparticles on multi-layers,the PL intensity of quantum dotsis enhanced approximately 5.029 times and the PL intensity of quantum dotsis enhanced 6.129times with thenanostar on multi-layers. We use COMSOL to simulate and choose single layer’s thickness to control the absorptionof substrate.We then use thermal evaporation to deposit DCJTB on multi-layers substrate.We found that the PL intensity of dyeon multi-layers is 4.007 times than that on glass substrate. After adding silver nanoparticles on multi-layers,the PL intensity of dye is enhanced approximately 5.634 times.Finally, we put nanostar on the substrate,PL intensity of dyeis enhanced 7.675times and its lifetime shrinks 42.2%
Zong, Han Ruei, and 宗函叡. "Metal Enhanced Fluorescence by Using Gold Nano-antenna on Hyperbolic Metamaterial Substrate." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/5un5e6.
Повний текст джерела國立臺灣海洋大學
光電科學研究所
105
In this paper, Fourier ion beam (FIB)、magnetron sputtering (Magnetron Sputter) are used to make the multilayered multilayer structure, and the antenna is strengthened by FIB etching to improve the field enhancement and directionality. We firstly usedScanning electron microscope (SEM) ,respectively to observe the surface roughness , thickness and the uniformityof the substrates.Ensure the width between the nano antenna. Secondly ,we used Photoluminescence to measure the light of absorption wave in the structure. For investigating the influences of photoluminescence (PL) and time-resolved photoluminescence (TRPL),we deposited the fluorescent dye "DCJTB" on the different thickness of hyperbolic meta-material . We observed that the PL intensity ofnano-antenna on HMM sample which deposited 75 nm DCJTB was increased about 17 times, and the lifetime could be shortened about 46% comparing with deposited 75nm DCJTB on Silicon. We demonstrated that the localized surface plasma of nano-antenna on HMM samples could enhance the resonance vibration strength of fluorescent molecules. Therefore, when the PL intensity is increased, the lifetime is shortened at the same time.
Cheng, Yue, and 成. 玥. "Cavity-enhanced spontaneous emission of dipole emitters on a hyperbolic metamaterial slab." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/3w4twz.
Повний текст джерела國立清華大學
光電工程研究所
106
We present an analytical description of the modes property for a dipole emitter when put above a gold nanorods hyperbolic metamaterials slab. In the long wavelength region, we simplify the hyperbolic metamaterials as an effective anisotropic medium and show that the optimized purcell factor originates from the imaginary part of the TM mode reflection coefficients, which is not only determined by bulk hyperbolic dispersion but also the selective slab thickness due to the Fabry-Perot resonance. We characterize the plane wave propagation inside the HMM slab as ‘critical coupling mode’ and ‘resonating mode’ and explain the dipole field enhancement in a view of angular expansion. Factors of HMM slab thickness, the metal fill ratio, metal loss and quenching effect are taken into discussion. Using the rigorous coupled wave analysis with the optimized geometry, we deliberately design a silicon bullseye grating and demonstrate more than 12 folds farfield radiation enhancement. This numerical method is not only suitable for nanorods HMM material but also for multilayer HMM material and other anisotropic medium, serving as an efficient tool for the design of high speed incoherent optical source devices.
Lee, Chung-Wei, and 李仲為. "Near-Infrared Surface Enhanced Raman Spectroscopy by Using Nano-Structures on Hyperbolic Metamaterial." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/dpn8e5.
Повний текст джерела國立臺灣海洋大學
光電科學研究所
105
In this study, we fabricated and characterized a large area of periodic germanium nanostructures on hyperbolic metamaterial (HMM) substrate by using nanosphere lithography (NSL) and then decorated the substrate with nano silver particles and star-shaped gold/sliver nanoparticles. At first, we used scanning electron microscope (SEM) to observe the surface of the substrates and measured the absorption spectrum of the structure to investigated the Surface Enhanced Raman Spectroscopy (SERS) with silver nanoparticles and star-shaped gold/sliver nanoparticles on different thickness of hyperbolic metamaterial (HMM). In the NIR Raman experiment, we used 4-aminothiophenol (4-ATP) to investigate the behaviors of different samples. We fabricated 3 different structures, star-shaped gold/sliver nanoparticles、Ge nanorod and silver particles on Ge HMM with four different thickness. Experimental results showed that Raman signal from HMM with 150nm in thickness had the strongest Raman signal due to the absorption peak near 1064nm.
Liu, Wei-Yung, and 劉偉雍. "Annealed AgOx Thin Film On Hyperbolic Metamaterial Substrate For Surface-Plasmon Enhanced Photoluminescence." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/nurcb5.
Повний текст джерела國立臺灣海洋大學
光電科學研究所
106
The annealed silver nanoparticles have been grown on hyperbolic metamaterial (HMM) by Multi-targets co-sputter system and Thermal coater, afterwards, surface morphology of the sample has been observed by Atomic Force Microscope (AFM) and then structural integrity and film uniformity of the sample have been investigated by Scanning Electron Microscope (SEM). In addition, the light absorption band of the structure is confirmed by spectrometer, and the influences of the silver particle sizes by different annealing temperatures to the Surface Enhanced Raman Spectroscopy (SERS) have been investigated. Photoluminescence (PL) and time-resolved photoluminescence (TRPL) have been measured after the thermal deposition of fluorescent dye on sample. The results show that annealed silver particles with fluorescent dye Alq3 on HMM can enhance the PL intensity by 12.23 times and reduce the PL life time by 32%, compared with fluorescent dye Alq3 on silicon substrate. Here we prove that surface plasmon resonance between hyperbolic metamaterial and silver nanoparticles can effectively increase the oscillatory intensity of the fluorescent molecules, the PL intensity and shorten the PL lifetime.
Wang, Guo-An, and 王國安. "Metallic nanoparticles covered on the decorated hyperbolic metamaterial substrate for Surface Enhanced Raman Scattering." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/aqf9sd.
Повний текст джерела國立臺灣海洋大學
光電科學研究所
103
In this thesis, wemainly used centrifugal method to arrange gold,silver, and unique star-shaped gold nanoparticles on silver-aluminum oxide substrate and Ge-Ag hyperbolic metamaterial substrate to fabricate the SERS substrate. Then, we employed these substrates to measure the Raman spectrum of molecules with different excitation wavelengths, including 532nm and 1064nm, to observe the effect of different metal nanoparticles generated in different excitation wavelength. And we used COMSOL multiphysics software to simulate SERS substrate’s absorborption and distribution of electric field intensity when the nanoparticles were aggregated. We found that the absorption spectrum peak of nanoparticle will be red-shifted and enhanced as nanoparticle aggregation occurs. When the laser excited at 532nm, we found that the Raman intensity of molecules adsorbed on silver nanoparticles over ALD substrates is greater than that adsorbed on silver nanoparticles over HMM substrate. That is due to coupling occurs when the substrate’s absorborption is very close to silver nanoparticle’s absorborption. On the other hand, star-shaped nanoparticle’s signal intensity is greater than gold nanoparticles under 1064nm Raman spectrum, that is because of the absorption spectrum peak of star-shaped nanoparticles at 974nm,which are very close to the laser wavelength, the surface plasma phenomena would be more stronger. Finally, we counted the number density of nanoparticles by using image J software and calculate the Raman spectra contributed from each nanoparticle. We found that the star-shaped nanoparticle’s signal intensity is greater than gold and silver nanoparticles under 1064nm Raman spectrum in the same density. On the ALD substrate, the Raman intensity of molecules adsorbed on mstar-shaped nanoparticles enhanced approximately 5.48 times than that adsorbed on gold nanoparticles under 1064nm Raman spectrum in the same density; the Raman intensity of molecules adsorbed on siliver nanoparticles enhanced approximately 1.49 times than that adsorbed on gold nanoparticles under 1064nm Raman spectrum in the same density. On the HMM substrate, the Raman intensity of molecules adsorbed on star-shaped nanoparticles enhanced approximately 7.17 times than that adsorbed on gold nanoparticles under 1064nm Raman spectrum in the same density; the Raman intensity of molecules adsorbed on siliver nanoparticles enhanced approximately 1.22 times than that adsorbed on gold nanoparticles under 1064nm Raman spectrum in the same density.
RONG, YANG DING, and 楊定融. "Near-infrared Surface Enhanced Raman Spectroscopy by Using Gold Antenna on Hyperbolic Metamaterial Substrate." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/q7d75y.
Повний текст джерела國立臺灣海洋大學
光電科學研究所
105
Abstract In this paper, we used focus-ion-beam (FIB) to mill gold antenna with concentric rings and magnetron sputter to fabricate the metamaterial with hyperbolic property. We then used these nano-structures to enhance the field strength and the directionality of nano-antenna. In the experiment, we firstly used the scanning electron microscope (SEM) to observe the surface of the structure, thickness of the film, integrity, uniformity, different sizes of the circles on hyperbolic metamaterial (HMM ) substrates, and coupling gap between two antenna. We also measured the absorption wavelength of the structure, and examined the characteristics of the samples by Raman spectroscopy to explore the effects of different concentric ring diameters for Surface Enhanced Raman Spectroscopy (SERS). The experimental data show that the 4-aminothiophenol (4-ATP) coated on the hyperbolic metamaterial substrate after milling the concentric rings antenna had an enhanced effect for the Raman signals of coated molecules. By combining hyperbolic metamaterial and gold/silver star-shaped nanoparticles, the Raman signal of 4-ATP can be enhanced up to 7.61 times as compared with that from bare HMM. Keyword: Surface Enhanced Raman Spectroscopy, Hyperbolic Metamaterial.
Yadav, Ravindra Kumar. "Study of room temperature coupling of colloidal quantum dots to plasmonic arrays and metamaterials: from single quantum dot to quantum dot assemblies." Thesis, 2020. https://etd.iisc.ac.in/handle/2005/5086.
Повний текст джерелаTsai, Kai-Hong, and 蔡凱鴻. "Surface enhanced Raman spectroscopy and metal enhanced fluorescence by using silver nanorod on hyperbolic metamaterial substrate." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/20301930376634705997.
Повний текст джерела國立臺灣海洋大學
光電科學研究所
104
In this study,we fabricated and characterized the substrates of silver nanorod array on hyperbolic metamaterial (HMM) by using thermal evaporation combined with oblique angle deposition (OAD),nanosphere lithography (NSL) and reactive-ion etching (RIE). At first, we used atomic force microscope (AFM) and scanning electron microscope (SEM),respectively, to observe the surface of the substrates and then measured theabsorptionspectra of the structure,and examined the characteristics ofthe substrates by Surface Enhanced Raman Spectroscopy (SERS). Finally, we deposited fluorescent dye "DCJTB" on the substrate and investigated its optical propoerties by using photoluminescence (PL) and time-resolved photoluminescence (TRPL). We observed that the PL intensity and lifetime of DCJTB75 nmin thickness deposited on silver nanorodsover HMM substrate was increased about 20.7times and could be shortened about 59%, respectively,as compared with those DCJTB deposted on bare silicon. We demonstrated that the localized surface plasmon of silver nanorodsover HMM substrates could enhance the resonance vibration strength of fluorescent molecules. Therefore, the PL intensity is increased and the lifetime is shortened at the same time.
Tsai, Ming-Chih, and 蔡旻志. "Cylindrical Plasmonic Waveguides Cladded by Hyperbolic Metamaterials." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/89545481109454995630.
Повний текст джерела國立臺灣大學
應用力學研究所
104
Conventional dielectric waveguides, such as optical fiber, cannot operate at the nanoscale due to the diffraction limit that light cannot be guided within the subwavelength structures. Plasmonic waveguides (PWs), guiding surface plasmon-polaritons (SPPs)––a form of surface waves which have smaller effective wavelength at the same frequency, make light can propagate in subwavelength dimensions and have been used in photonic integrated circuits. However, the propagation length of SPPs in PWs are limited due to the losses of metal. Hybrid plasmonic waveguides (HPWs) combine the advantages of the dielectric waveguides and the PWs, which have a balanced performance between high confinement and long-range propagation. On the other hand, anisotropic material has been used to control the optical momentum of waves in different directions. In this study, we propose and analyze a new design of cylindrical PWs based on strongly anisotropic media––hyperbolic metamaterial, that is, cylindrical PWs cladded by hyperbolic metamaterials or metal–dielectric–hyperbolic (MDH) cylindrical waveguides. This new type of waveguides has similar function as the HPWs with high field confinement and the long propagation length. We analytically solve the basic properties of the MDH cylindrical waveguides: First, we derive the dispersion equation of three-layer anisotropic cylindrical waveguides based on Maxwell’s equations. Second, the propagation constant, propagation length, mode area and the figure of merit (FOM) of the transverse magnetic modes are obtained from the dispersion relation. Through observing the trend of the FOM, we found the MDH cylindrical waveguides have high field confinement which approximates to the isotropic metal–dielectric–metal (MDM) cylindrical waveguides. Nevertheless, the propagation losses will be sharply reduced, which leads to the longer propagation length. For example, for the case of Ag–ZnO–hyperbolic cylindrical waveguides with the size around 400 nm at wavelength, it perform both extremely small mode area that approximates to the Ag–ZnO–Ag cylindrical waveguides and better propagation length which is almost twice longer than that of the MDM cases.
Kao, Tzu Hung, and 高子紘. "Study on the Characteristics of Helix Photonic Metamaterials and Nanowires Hyperbolic Metamaterials." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/81722832129264427068.
Повний текст джерела國立清華大學
光電工程研究所
104
Chiral structures exhibit strong interactions with circularly polarized light, and have been demonstrated to show many polarization dependent properties, such as circular dichroism. In this study, we use a complete and incomplete dielectric helix array as a model system to examine the interactions of circularly polarized light with helical structures. A dielectric helix array produces the circular polarization band gaps having not only the same handedness with the structure but also the opposite handedness. The gap with the opposite handedness results from additional chiral motifs induced by the adjacent helices. Dual polarization band gaps can thus be tailored by varying the geometrical parameters, and circular-polarization dependent properties can be manipulated for optoelectronic devices and applications. Hyperbolic metamaterial (HMM) has attracted considerable attention owing to several exotic optical properties. One of these is the enhanced spontaneous emission, resulting from the hyperbolic dispersion of HMM. However, the out-coupling of light from HMMs is difficult due to the evanescent character of the high-k modes at the surface. In this study, the optical properties of nanowire HMMs with the enhanced structure are characterized. The results show the loss in the system is reduced, and the high-k modes of HMM is coupled out by virtue of the enhanced structure. The radiative enhancement can reach the value of 7.2 in the infrared region. The resonances inside the nanowire HMM are also analyzed to examine the mechanism of the enhancement of light. The analysis results are important toward engineering highly-efficient photonic devices based on HMMs.
"Large broad-angle broad-band Goos-Hänchen shift in graded hyperbolic metamaterials." 2013. http://library.cuhk.edu.hk/record=b5884441.
Повний текст джерелаThesis (M.Phil.)--Chinese University of Hong Kong, 2013.
Includes bibliographical references (leaves 78-82).
Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web.
Abstracts also in Chinese.
Hui, Ka Shing = Ti du de ge xiang yi xing chao cai liao de guang jiao du de Gusi-han xin wei yi / Xu Jiacheng.
SPINOZZI, ELISA. "Linear and non-linear photonic properties and applications of hyperbolic metamaterials." Doctoral thesis, 2013. http://hdl.handle.net/11573/918235.
Повний текст джерелаUn, Ieng-Wai, and 阮英偉. "Phase Transition, Interface States and Bulk-Interface Correspondence of One-Dimensional Hyperbolic Metamaterials." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/8gr6z8.
Повний текст джерелаYu, Cheng-Li, and 余承澧. "Spontaneous Emission Enhancement in Two- dimensional Molybdenum Disulfide (MoS2) using Planar Hyperbolic Metamaterials." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/6q3dy7.
Повний текст джерела國立交通大學
光電工程研究所
105
Recently, increasing attentions are paid to the two-dimensional materials especially TMDCs due to its direct band gap light emission. It was view as a next generation semiconductor materials which would apply to the optoelectronic device. However, challenging of TMDCs was that they suffered weak quantum yield. Therefore, in this study, we demonstrated the spontaneous emmission enhancement of MoS2 on the planar hyperbolic metamaterials (P- HMMs). In the first part, we designed the planar P-HMM at the PL wavelength of MoS2 which have the better mode coupling in the vertical direction compared to multilayers HMMs. Moreover, its anisotropic property make the PL of MoS2 led to in-plane confinement and resonance. Therefore, the strong coupling between structure and two-dimensional materials and spontaneous emission enhancement was observed in both experiment and simulation. In the second part, we started to curved the planar 1-D HMM into the concentric planar HMM (CPHMM) because we expected the better resonance in the ring cavity. On one hand, because the concentric structure could support the Whisper Gallery Mode (WGM) resonance compared to one dimensional resonance, the higher spontaneous emission enhancement of MoS2 with CP-HMM was observed than enhancement with P-HMM. On the other hand, by the photoluminescence mapping analysis, the highest happened at the inner edge of CP-HMM than other position of CP-HMM. It meant the energy concentration at the inner edge which led to the stronger mode coupling to the two-dimensional materials led to the higher enhancement. The similar results was also confirmed by the simulation results by Finite Element Method. Therefore, it showed the possibility to develop the ultrasmall light source combing subwavelength cavity and atomic thick two-dimensional materials.
Wei, Chih-Kuang, and 魏志光. "Experimentally Demonstrate the Surface State and Optical Topological Phase Transition of One Dimensional Hyperbolic Metamaterials." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/n82dx9.
Повний текст джерела國立清華大學
材料科學工程學系
105
The optical responses of one dimensional hyperbolic metamaterials (1DHMMs) are usually determined by effective medium theory based on the long wavelength approximation. However, the long wavelength approximation shows significant deviation when the wavelength of the incident light is comparable with the unit cell of HMMs. Therefore, plasmonic band theory have been suggested to analyze the 1DHMMs recently and the existence of the interface state has been proposed. The requirement for the existence of the interface state is determined by the admittance matching condition. Furthermore, the interface state formation in the plasmonic band gap can be related to the properties of the plasmonic band in terms of the wave admittance, so called “bulk-interface correspondence”. In this work, we experimentally identify the existence of the interface state of 1DHMM by the Kretschmann and the Otto configurations. By varying the metallic filling ratio in the 1DHMMs, we successfully demonstrate the disappearance and reappearance of the interface state which indicates the optical topological phase transition of 1DHMMs.
San, Roman Alerigi Damian. "Exploring Heterogeneous and Time-Varying Materials for Photonic Applications, Towards Solutions for the Manipulation and Confinement of Light." Diss., 2014. http://hdl.handle.net/10754/335793.
Повний текст джерела