Metamaterials and Negative Refraction
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Far-Field Optical Imaging of Viruses Using Surface Plasmon Polariton
Magnifying superlens in the visible frequency range. I.I. Smolyaninov, Y.J.Hung , and C.C. Davis Department of Electrical and Computer Engineering, University of Maryland, College Park, MD 20742, USA Optical microscopy is an invaluable tool for studies of materials and biological entities. With the current progress in nanotechnology and microbiology imaging tools with ever increasing spatial resolution are required. However, the spatial resolution of the conventional microscopy is limited by the diffraction of light waves to a value of the order of 200 nm. Thus, viruses, proteins, DNA molecules and many other samples are impossible to visualize using a regular microscope. The new ways to overcome this limitation may be based on the concept of superlens introduced by J. Pendry [1]. This concept relies on the use of materials which have negative refractive index in the visible frequency range. Even though superlens imaging has been demonstrated in recent experiments [2], this technique is still limited by the fact that magnification of the planar superlens is equal to 1. In this communication we introduce a new design of the magnifying superlens and demonstrate it in the experiment. Our design has some common features with the recently proposed “optical hyperlens” [3], “metamaterial crystal lens” [4], and the plasmon-assisted microscopy technique [5]. The internal structure of the magnifying superlens is shown in Fig.1(a). It consists of the concentric rings of polymethyl methacrylate (PMMA) deposited on the gold film surface. Due to periodicity of the structure in the radial direction surface plasmon polaritons (SPP) [5] are excited on the lens surface when the lens is illuminated from the bottom with an external laser. -
Optical Negative-Index Metamaterials
REVIEW ARTICLE Optical negative-index metamaterials Artifi cially engineered metamaterials are now demonstrating unprecedented electromagnetic properties that cannot be obtained with naturally occurring materials. In particular, they provide a route to creating materials that possess a negative refractive index and offer exciting new prospects for manipulating light. This review describes the recent progress made in creating nanostructured metamaterials with a negative index at optical wavelengths, and discusses some of the devices that could result from these new materials. VLADIMIR M. SHALAEV designed and placed at desired locations to achieve new functionality. One of the most exciting opportunities for metamaterials is the School of Electrical and Computer Engineering and Birck Nanotechnology development of negative-index materials (NIMs). Th ese NIMs bring Center, Purdue University, West Lafayette, Indiana 47907, USA. the concept of refractive index into a new domain of exploration and e-mail: [email protected] thus promise to create entirely new prospects for manipulating light, with revolutionary impacts on present-day optical technologies. Light is the ultimate means of sending information to and from Th e arrival of NIMs provides a rather unique opportunity for the interior structure of materials — it packages data in a signal researchers to reconsider and possibly even revise the interpretation of zero mass and unmatched speed. However, light is, in a sense, of very basic laws. Th e notion of a negative refractive index is one ‘one-handed’ when interacting with atoms of conventional such case. Th is is because the index of refraction enters into the basic materials. Th is is because from the two fi eld components of light formulae for optics. -
Commencement Program
Sunday, the Sixteenth of May, Two Thousand and Ten ten o’clock in the morning ~ wallace wade stadium Duke University Commencement ~ 2010 One Hundred Fifty-Eighth Commencement Notes on Academic Dress Academic dress had its origin in the Middle Ages. When the European universities were taking form in the thirteenth and fourteenth centuries, scholars were also clerics, and they adopted Mace and Chain of Office robes similar to those of their monastic orders. Caps were a necessity in drafty buildings, and Again at commencement, ceremonial use is copes or capes with hoods attached were made of two important insignia given to Duke needed for warmth. As the control of universities University in memory of Benjamin N. Duke. gradually passed from the church, academic Both the mace and chain of office are the gifts costume began to take on brighter hues and to of anonymous donors and of the Mary Duke employ varied patterns in cut and color of gown Biddle Foundation. They were designed and and type of headdress. executed by Professor Kurt J. Matzdorf of New The use of academic costume in the United Paltz, New York, and were dedicated and first States has been continuous since Colonial times, used at the inaugural ceremonies of President but a clear protocol did not emerge until an Sanford in 1970. intercollegiate commission in 1893 recommended The Mace, the symbol of authority of the a uniform code. In this country, the design of a University, is made of sterling silver throughout. gown varies with the degree held. The bachelor’s Significance of Colors It is thirty-seven inches long and weighs about gown is relatively simple with long pointed Colors indicating fields of eight pounds. -
Negative Refractive Index in Artificial Metamaterials
1 Negative Refractive Index in Artificial Metamaterials A. N. Grigorenko Department of Physics and Astronomy, University of Manchester, Manchester, M13 9PL, UK We discuss optical constants in artificial metamaterials showing negative magnetic permeability and electric permittivity and suggest a simple formula for the refractive index of a general optical medium. Using effective field theory, we calculate effective permeability and the refractive index of nanofabricated media composed of pairs of identical gold nano-pillars with magnetic response in the visible spectrum. PACS: 73.20.Mf, 41.20.Jb, 42.70.Qs 2 The refractive index of an optical medium, n, can be found from the relation n2 = εμ , where ε is medium’s electric permittivity and μ is magnetic permeability.1 There are two branches of the square root producing n of different signs, but only one of these branches is actually permitted by causality.2 It was conventionally assumed that this branch coincides with the principal square root n = εμ .1,3 However, in 1968 Veselago4 suggested that there are materials in which the causal refractive index may be given by another branch of the root n =− εμ . These materials, referred to as left- handed (LHM) or negative index materials, possess unique electromagnetic properties and promise novel optical devices, including a perfect lens.4-6 The interest in LHM moved from theory to practice and attracted a great deal of attention after the first experimental realization of LHM by Smith et al.7, which was based on artificial metallic structures -
Phase Reversal Diffraction in Incoherent Light
Phase Reversal Diffraction in incoherent light Su-Heng Zhang1, Shu Gan1, De-Zhong Cao2, Jun Xiong1, Xiangdong Zhang1 and Kaige Wang1∗ 1.Department of Physics, Applied Optics Beijing Area Major Laboratory, Beijing Normal University, Beijing 100875, China 2.Department of Physics, Yantai University, Yantai 264005, China Abstract Phase reversal occurs in the propagation of an electromagnetic wave in a negatively refracting medium or a phase-conjugate interface. Here we report the experimental observation of phase reversal diffraction without the above devices. Our experimental results and theoretical analysis demonstrate that phase reversal diffraction can be formed through the first-order field correlation of chaotic light. The experimental realization is similar to phase reversal behavior in negatively refracting media. PACS numbers: 42.87.Bg, 42.30.Rx, 42.30.Wb arXiv:0908.1522v1 [quant-ph] 11 Aug 2009 ∗ Corresponding author: [email protected] 1 Diffraction changes the wavefront of a travelling wave. A lens is a key device that can modify the wavefront and perform imaging. The complete recovery of the wavefront is possible if its phase evolves backward in time in which case an object can be imaged to give an exact copy. A phase-conjugate mirror formed by a four-wave mixing process is able to generate the conjugate wave with respect to an incident wave and thus achieve lensless imaging[1]. A slab of negative refractive-index material can play a role similar to a lens in performing imaging[2, 3, 4, 5, 6, 7]. Pendry in a recent paper[8] explored the similarity between a phase-conjugate interface and negative refraction, and pointed out their intimate link to time reversal. -
Millennium Development Holes
www.nature.com/nature Vol 446 | Issue no. 7134 | 22 March 2007 Millennium development holes The political commitment to helping the developing world is failing to deliver on its promises. The problem is made worse by the questionable evaluation of progress. n 2000, 189 world leaders committed to eight Millennium Devel- few developing countries have any data for around 1990, the baseline opment Goals (MDGs), ranging from halving extreme poverty and year. It is impossible to estimate progress for most of the indicators Ihunger, and rolling back killer diseases such as AIDS and malaria, over less than five years, and sparse poverty data can only be reliably to providing universal primary education. The deadline of 2015 to compared over decades. To pretend that progress towards the 2015 achieve all these ambitious goals is now rapidly approaching. goals can be accurately and continually measured is false. As a rallying cry that has pushed development up the inter national Significant efforts are now being made to improve data collection. political agenda, the goals have been an indisputable success. They Meanwhile, UN agencies fill in the missing data points using ‘model- have also, for better or worse, conferred power and legitimacy on ling’ — in practice, a recipe for potentially misleading extrapolation interests within the international aid machine, in particular the and political tampering. United Nations (UN) and the World Bank. Indeed, the lack of data makes it impossible not only to track But the goals are ultimately political promises, and as such they progress, but also to assess the effectiveness of measures taken. -
Advanced Metamaterials for High Resolution Focusing and Invisibility Cloaks
Doctoral thesis submitted for the degree of Doctor of Philosophy in Telecommunication Engineering Postgraduate programme: Communication Technology Advanced metamaterials for high resolution focusing and invisibility cloaks Presented by: Bakhtiyar Orazbayev Director: Dr. Miguel Beruete Díaz Pamplona, November 2016 Abstract Metamaterials, the descendants of the artificial dielectrics, have unusual electromagnetic parameters and provide more abilities than naturally available dielectrics for the control of light propagation. Being able to control both permittivity and permeability, metamaterials have opened a way to obtain a double negative medium. The first experimental realization of such medium gave an enormous impulse for research in the field of electromagnetism. As result, many fascinating electromagnetic devices have been developed since then, including metamaterial lenses, beam steerers and even invisibility cloaks. The possible applications of metamaterials are not limited to these devices and can be applied in many fields, such as telecommunications, security systems, biological and chemical sensing, spectroscopy, integrated nano-optics, nanotechnology, medical imaging systems, etc. The aim of this doctoral thesis, performed at the Public University of Navarre in collaboration with the University of Texas at Austin, the Valencia Nanophotonics Technology Center in the UPV and King’s College London, is to contribute to the development of metamaterial based devices, including their fabrication and, when possible, experimental verification. The thesis is not focused on a single application or device, but instead tries to provide an extensive exploration of the different metamaterial devices. These results include the following: Three different lens designs based on a fishnet metamaterial are presented: a broadband zoned fishnet metamaterial lens, a Soret fishnet metamaterial lens and a Wood zone plate fishnet metamaterial. -
Chapter 19/ Optical Properties
Chapter 19 /Optical Properties The four notched and transpar- ent rods shown in this photograph demonstrate the phenomenon of photoelasticity. When elastically deformed, the optical properties (e.g., index of refraction) of a photoelastic specimen become anisotropic. Using a special optical system and polarized light, the stress distribution within the speci- men may be deduced from inter- ference fringes that are produced. These fringes within the four photoelastic specimens shown in the photograph indicate how the stress concentration and distribu- tion change with notch geometry for an axial tensile stress. (Photo- graph courtesy of Measurements Group, Inc., Raleigh, North Carolina.) Why Study the Optical Properties of Materials? When materials are exposed to electromagnetic radia- materials, we note that the performance of optical tion, it is sometimes important to be able to predict fibers is increased by introducing a gradual variation and alter their responses. This is possible when we are of the index of refraction (i.e., a graded index) at the familiar with their optical properties, and understand outer surface of the fiber. This is accomplished by the mechanisms responsible for their optical behaviors. the addition of specific impurities in controlled For example, in Section 19.14 on optical fiber concentrations. 766 Learning Objectives After careful study of this chapter you should be able to do the following: 1. Compute the energy of a photon given its fre- 5. Describe the mechanism of photon absorption quency and the value of Planck’s constant. for (a) high-purity insulators and semiconduc- 2. Briefly describe electronic polarization that re- tors, and (b) insulators and semiconductors that sults from electromagnetic radiation-atomic in- contain electrically active defects. -
Super-Resolution Imaging by Dielectric Superlenses: Tio2 Metamaterial Superlens Versus Batio3 Superlens
hv photonics Article Super-Resolution Imaging by Dielectric Superlenses: TiO2 Metamaterial Superlens versus BaTiO3 Superlens Rakesh Dhama, Bing Yan, Cristiano Palego and Zengbo Wang * School of Computer Science and Electronic Engineering, Bangor University, Bangor LL57 1UT, UK; [email protected] (R.D.); [email protected] (B.Y.); [email protected] (C.P.) * Correspondence: [email protected] Abstract: All-dielectric superlens made from micro and nano particles has emerged as a simple yet effective solution to label-free, super-resolution imaging. High-index BaTiO3 Glass (BTG) mi- crospheres are among the most widely used dielectric superlenses today but could potentially be replaced by a new class of TiO2 metamaterial (meta-TiO2) superlens made of TiO2 nanoparticles. In this work, we designed and fabricated TiO2 metamaterial superlens in full-sphere shape for the first time, which resembles BTG microsphere in terms of the physical shape, size, and effective refractive index. Super-resolution imaging performances were compared using the same sample, lighting, and imaging settings. The results show that TiO2 meta-superlens performs consistently better over BTG superlens in terms of imaging contrast, clarity, field of view, and resolution, which was further supported by theoretical simulation. This opens new possibilities in developing more powerful, robust, and reliable super-resolution lens and imaging systems. Keywords: super-resolution imaging; dielectric superlens; label-free imaging; titanium dioxide Citation: Dhama, R.; Yan, B.; Palego, 1. Introduction C.; Wang, Z. Super-Resolution The optical microscope is the most common imaging tool known for its simple de- Imaging by Dielectric Superlenses: sign, low cost, and great flexibility. -
All-Angle Negative Refraction Without Negative Effective Index
RAPID COMMUNICATIONS PHYSICAL REVIEW B, VOLUME 65, 201104͑R͒ All-angle negative refraction without negative effective index Chiyan Luo, Steven G. Johnson, and J. D. Joannopoulos* Department of Physics and Center for Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 J. B. Pendry Condensed Matter Theory Group, The Blackett Laboratory, Imperial College, London SW7 2BZ, United Kingdom ͑Received 22 January 2002; published 13 May 2002͒ We describe an all-angle negative refraction effect that does not employ a negative effective index of refraction and involves photonic crystals. A few simple criteria sufficient to achieve this behavior are presented. To illustrate this phenomenon, a microsuperlens is designed and numerically demonstrated. DOI: 10.1103/PhysRevB.65.201104 PACS number͑s͒: 78.20.Ci, 42.70.Qs, 42.30.Wb Negative refraction of electromagnetic waves in ‘‘left- We observe from Fig. 1 that due to the negative-definite ץ ץ 2ץ handed materials’’ has become of interest recently because it photonic effective mass / ki k j at the M point, the fre- is the foundation for a variety of novel phenomena.1–6 In quency contours are convex in the vicinity of M and have particular, it has been suggested that negative refraction leads inward-pointing group velocities. For frequencies that corre- to a superlensing effect that can potentially overcome the spond to all-convex contours, negative refraction occurs as diffraction limit inherent in conventional lenses.2 These phe- illustrated in Fig. 2. The distinct refracted propagating modes nomena have been described in the context of an effective- are determined by the conservation of the frequency and the medium theory with negative index of refraction, and at the wave-vector component parallel to the air/photonic-crystal moment only appear possible in the microwave regime. -
Realization of an All-Dielectric Zero-Index Optical Metamaterial
Realization of an all-dielectric zero-index optical metamaterial Parikshit Moitra1†, Yuanmu Yang1†, Zachary Anderson2, Ivan I. Kravchenko3, Dayrl P. Briggs3, Jason Valentine4* 1Interdisciplinary Materials Science Program, Vanderbilt University, Nashville, Tennessee 37212, USA 2School for Science and Math at Vanderbilt, Nashville, TN 37232, USA 3Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA 4Department of Mechanical Engineering, Vanderbilt University, Nashville, Tennessee 37212, USA †these authors contributed equally to this work *email: [email protected] Metamaterials offer unprecedented flexibility for manipulating the optical properties of matter, including the ability to access negative index1–4, ultra-high index5 and chiral optical properties6–8. Recently, metamaterials with near-zero refractive index have drawn much attention9–13. Light inside such materials experiences no spatial phase change and extremely large phase velocity, properties that can be applied for realizing directional emission14–16, tunneling waveguides17, large area single mode devices18, and electromagnetic cloaks19. However, at optical frequencies previously demonstrated zero- or negative- refractive index metamaterials require the use of metallic inclusions, leading to large ohmic loss, a serious impediment to device applications20,21. Here, we experimentally demonstrate an impedance matched zero-index metamaterial at optical frequencies based on purely dielectric constituents. Formed from stacked silicon rod unit cells, the metamaterial possesses a nearly isotropic low-index response leading to angular selectivity of transmission and directive emission from quantum dots placed within the material. Over the past several years, most work aimed at achieving zero-index has been focused on epsilon-near-zero metamaterials (ENZs) which can be realized using diluted metals or metal waveguides operating below cut-off. -
The Physics of Negative Refraction and Transformation Optics
The Physics of Negative Refraction and Transformation Optics by Wei Hsiung Wee Thesis submitted for the degree of Doctor of Philosophy Condensed Matter Theory Group Department of Physics Imperial College London June 2011 Declaration of Originality This thesis is a result of the author’s own work. All other work contained within are appropriately referenced to the best of the author’s knowledge. Abstract Whilst optics is one of the oldest field in science, there are still aspects of electromag- netism that we are only beginning to uncover. For instance, it was demonstrated that materials with simultaneously negative permittivity and permeability exhibit certain exotic behavior; where familiar physical phenomena, such as refraction, are reversed. As such, these materials came to be known as negative refractive index materials (NRIM) and their collective properties as negative refraction. One of the most important and remarkable property of NRIM is perfect lensing - the ability to transport both supra and sub-wavelength optical information from one surface (ob- ject plane) to another (image plane), forming images with unprecedented resolution, beyond the diffraction limit. Perfect lensing itself is a consequence of deeper sym- metries in electromagnetism, encapsulated in the language of transformation optics - with which we have both a descriptive tool to unify diverse electromagnetic con- figuarations, as well as a prescriptive tool to design media which bends light at will. While, such transformation medium and NRIM have been demonstrably realised using metamaterials, several challenges remain, of which loss is the major challenge. It is therefore under this trinity of concepts: metamaterials, negative refraction and transformation optics that this thesis is presented.