Metamaterial with randomized patterns for negative refraction of electromagnetic waves
TL;DR: In this paper, a metamaterial characterized by a constitutive relation with negative constitutive parameters is produced in solid-state form by randomizing contour patterns deposited lithographically on circuit board materials.
Abstract: Artificial metamaterials made to date are all periodic in structure. Here we show that by randomizing contour patterns deposited lithographically on circuit board materials, a metamaterial characterized by a constitutive relation with negative constitutive parameters is produced in solid-state form. We clearly demonstrate the phenomenon of negative refraction to show that it is not produced by periodicity. This underlines the importance of using constitutive relations for media characterization in electromagnetic theory and suggests that metamaterials could be realized with composite materials or fabricated with various techniques by using versatile hosting materials.
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Book•
26 Sep 2008
TL;DR: The concept of negative refraction was introduced in this article, where the wave-vector and its consequences were investigated in anisotropic and chiral media with negative refractive index materials.
Abstract: Introduction General historical perspective The concept of metamaterials Modeling the material response Phase velocity and group velocity Metamaterials and homogenization procedure Metamaterials and Homogenization of Composites The homogenization hypothesis Limitations and consistency conditions Forward problem Inverse problems: retrieval and constitutive parameters Homogenization from averaging the internal fields Generalization to anisotropic and bianisotropic media Designing Metamaterials with Negative Material Parameters Negative dielectric materials Metamaterials with negative magnetic permeability Metamaterials with negative refractive index Chiral metamaterials Bianisotropic metamaterials Active and nonlinear metamaterials Negative Refraction and Photonic Bandgap Materials Photonic crystals and bandgap materials Band diagrams and iso-frequency contours Negative refraction and flat lenses with photonic crystals Negative refraction versus collimation or streaming Media with e < 0 and < 0: Theory and Properties Origins of negative refraction Choice of the wave-vector and its consequences Anisotropic and chiral media Energy and Momentum in Negative Refractive Index Materials Causality and energy density in frequency dispersive media Electromagnetic energy in left-handed media Momentum density, momentum flow, and transfer in media with negative material parameters Limit of plane waves and small losses Traversal of pulses in materials with negative material parameters Plasmonics of Media with Negative Material Parameters Surface electromagnetic modes in negative refractive materials Waveguides made of negative index materials Negative refraction of surface plasmons Plasmonic properties of structured metallic surfaces Surface waves at the interfaces of nonlinear media Veselago's Lens Is a Perfect Lens Near-field information and diffraction limit Mathematical demonstration of the perfect lens Limitations due to real materials and imperfect NRMs Issues with numerical simulations and time evolution Negative stream of energy with a perfect lens configuration Effects of spatial dispersion Designing Super Lenses Overcoming the limitations of real materials Generalized perfect lens theorem The perfect lens in other geometries Brief Report on Electromagnetic Invisibility Concept of electromagnetic invisibility Excluding electromagnetic fields Cloaking with localized resonances Appendix A: The Fresnel Coefficients for Reflection and Refraction Appendix B: The Dispersion and Fresnel Coefficients for a Bianisotropic Medium Appendix C: The Reflection and Refraction of Light across a Material Slab References Index
219 citations
TL;DR: In this article, the authors provide an overview of the fabrications, exotic properties, and their applications especially in the wireless power transfer (WPT) field, while the perspective and future challenges of metamaterials and WPT are proposed.
Abstract: Metamaterials have been deployed for a wide range of fields including invisible cloak, superlens, electromagnetic wave absorption and magnetic resonance imaging, owing to their peculiar electromagnetic properties. However, few investigations on metamaterials were focused on wireless power transfer (WPT). WPT is the transmission of electrical energy from a power source to an electrical load without conductors like wires or cables. Metamaterials can enhance the transfer efficiency and enlarge the transfer distance due to their ability of focusing magnetic flux, which opens up a novel approach to promoting the development and application of WPT. This review paper aims to provide an overview of the fabrications, exotic properties, and their applications especially in the WPT field. Meanwhile, the perspective and future challenges of metamaterials and WPT are proposed.
156 citations
TL;DR: In this paper, the effects of disorder on metamaterial samples composed of split ring resonators with randomly introduced variation in their geometrical dimensions were investigated, and it was shown that disorder broadens the negative permeability band and introduces effective losses into the system.
Abstract: We investigate the effects of disorder on metamaterial samples composed of split ring resonators with randomly introduced variation in their geometrical dimensions. We demonstrate that disorder broadens the negative permeability band and introduces effective losses into the system. Transmission measurements on samples with varying degrees of disorder are found to be in excellent agreement with predictions based on standard homogenization theories.
53 citations
01 Jan 2007
TL;DR: The properties of planar, single-layer metamaterials, or metafilms, are studied by varying the structural components of the split-ring resonators used to comprise the overall medium in this paper.
Abstract: The properties of planar, single-layer metamaterials, or metafilms, are studied by varying the structural components of the split-ring resonators used to comprise the overall medium. Measurements and simulations reveal how minor design variations in split-ring resonator structures can result in significant changes in the macroscopic properties of the metafilm. A transmission-line/circuit model is also used to clarify some of the behavior and design limitations of the metafilms. Though our results are illustrated in the terahertz frequency range, the work has broader implications, particularly with respect to filtering, modulation, and switching devices.
51 citations
TL;DR: In this article, the experimental progress in the metamaterial, focusing on their constitutive parameters and material performance, is reviewed, and two fabrication approaches: the structure approach that is widely used to construct periodic metammaterial structures, and the chemical approach is very promising in constructing nano-scaled metamural with randomized patterns, are discussed.
Abstract: Electromagnetic metamaterials are artificial materials composed of subwavelength structures to provide unusual effective macroscopic behavior not found in nature. These materials are characterized by constitutive relations which contain a maximum of 36 complex constitutive parameters. With different combinations of positive and negative parameters in the constitutive tensors, striking phenomena and novel applications were discovered. In this Feature Article, I briefly review the experimental progress in the metamaterial, focusing on their constitutive parameters and material performance, e.g. the bandwidth, the loss, and the electrical size with respect to the operating wavelength, etc. The two fabrication approaches: the structure approach that is widely used to construct periodic metamaterial structures, and the chemical approach that is very promising in constructing nano-scaled metamaterial with randomized patterns, are discussed. The practical potential of this field and the possible challenging future work are pointed out in the conclusion.
50 citations
References
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10,495 citations
Book•
01 Jan 1873
TL;DR: The most influential nineteenth-century scientist for twentieth-century physics, James Clerk Maxwell (1831-1879) demonstrated that electricity, magnetism and light are all manifestations of the same phenomenon: the electromagnetic field as discussed by the authors.
Abstract: Arguably the most influential nineteenth-century scientist for twentieth-century physics, James Clerk Maxwell (1831–1879) demonstrated that electricity, magnetism and light are all manifestations of the same phenomenon: the electromagnetic field. A fellow of Trinity College Cambridge, Maxwell became, in 1871, the first Cavendish Professor of Physics at Cambridge. His famous equations - a set of four partial differential equations that relate the electric and magnetic fields to their sources, charge density and current density - first appeared in fully developed form in his 1873 Treatise on Electricity and Magnetism. This two-volume textbook brought together all the experimental and theoretical advances in the field of electricity and magnetism known at the time, and provided a methodical and graduated introduction to electromagnetic theory. Volume 2 covers magnetism and electromagnetism, including the electromagnetic theory of light, the theory of magnetic action on light, and the electric theory of magnetism.
9,565 citations
TL;DR: These experiments directly confirm the predictions of Maxwell's equations that n is given by the negative square root ofɛ·μ for the frequencies where both the permittivity and the permeability are negative.
Abstract: We present experimental scattering data at microwave frequencies on a structured metamaterial that exhibits a frequency band where the effective index of refraction (n) is negative. The material consists of a two-dimensional array of repeated unit cells of copper strips and split ring resonators on interlocking strips of standard circuit board material. By measuring the scattering angle of the transmitted beam through a prism fabricated from this material, we determine the effective n, appropriate to Snell's law. These experiments directly confirm the predictions of Maxwell's equations that n is given by the negative square root of epsilon.mu for the frequencies where both the permittivity (epsilon) and the permeability (mu) are negative. Configurations of geometrical optical designs are now possible that could not be realized by positive index materials.
8,477 citations
TL;DR: In this paper, it was shown that microstructures built from nonmagnetic conducting sheets exhibit an effective magnetic permeability /spl mu/sub eff/, which can be tuned to values not accessible in naturally occurring materials.
Abstract: We show that microstructures built from nonmagnetic conducting sheets exhibit an effective magnetic permeability /spl mu//sub eff/, which can be tuned to values not accessible in naturally occurring materials, including large imaginary components of /spl mu//sub eff/. The microstructure is on a scale much less than the wavelength of radiation, is not resolved by incident microwaves, and uses a very low density of metal so that structures can be extremely lightweight. Most of the structures are resonant due to internal capacitance and inductance, and resonant enhancement combined with compression of electrical energy into a very small volume greatly enhances the energy density at critical locations in the structure, easily by factors of a million and possibly by much more. Weakly nonlinear materials placed at these critical locations will show greatly enhanced effects raising the possibility of manufacturing active structures whose properties can be switched at will between many states.
8,135 citations
TL;DR: A composite medium, based on a periodic array of interspaced conducting nonmagnetic split ring resonators and continuous wires, that exhibits a frequency region in the microwave regime with simultaneously negative values of effective permeability and permittivity varepsilon(eff)(omega).
Abstract: We demonstrate a composite medium, based on a periodic array of interspaced conducting nonmagnetic split ring resonators and continuous wires, that exhibits a frequency region in the microwave regime with
8,057 citations