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Journal ArticleDOI

Peculiarities in the dielectric response of negative-permittivity scatterers

01 Jan 2006-Progress in Electromagnetics Research-pier (E M W PUBLISHING)-Vol. 66, pp 191-198
TL;DR: In this article, the polarizability properties of spherically layered small inclusions that possess negative permittivity were analyzed and conditions for invisibility to external electric fields were derived.
Abstract: This study analyzes polarizability properties of spherically layered small inclusions that possess negative permittivity. Conditions for invisibility to external electric fields are derived. The complementary principle for two-dimensional scatterers is used to derive special properties of self-complementary inclusions. A singular behavior between the limits of invisibility and infinite response is underlined for a hollow circular shell. A similar,although not as drastic,phenomenon is shown to take place for the three-dimensional hollow sphere.

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Citations
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Journal ArticleDOI
TL;DR: Analytically the interactions of electromagnetic wave with a general class of spherical cloaks based on a full wave Mie scattering model is established and it is shown that for an ideal cloak the total scattering cross section is absolutely zero, but for a cloak with a specific type of loss, only the backscattering is exactly zero.
Abstract: We establish analytically the interactions of electromagnetic wave with a general class of spherical cloaks based on a full wave Mie scattering model. We show that for an ideal cloak the total scattering cross section is absolutely zero, but for a cloak with a specific type of loss, only the backscattering is exactly zero, which indicates the cloak can still be rendered invisible with a monostatic (transmitter and receiver in the same location) detection. Furthermore, we show that for a cloak with imperfect parameters the bistatic (transmitter and receiver in different locations) scattering performance is more sensitive to eta(t)=square root micro(t)/epsilon(t) than n(t)=square root micro(t)epsilon(t).

483 citations

Journal ArticleDOI
TL;DR: In this paper, the authors investigated a general class of electromagnetic devices created with any continuous transformation functions by rigorously calculating the analytical expressions of the electromagnetic field in the whole space, and they proposed a spherical field rotator which functions as not only a wave vector rotator but also a polarization rotator depending on the orientations of the spherical rotator with respect to the incident wave direction.
Abstract: We investigate a general class of electromagnetic devices created with any continuous transformation functions by rigorously calculating the analytical expressions of the electromagnetic field in the whole space. Some interesting phenomena associated with these transformation devices, including the invisibility cloaks, concentrators, and field rotators, are discussed. By carefully choosing the transformation function, we can realize cloaks, which are insensitive to perturbations at both the inner and outer boundaries. Furthermore, we find that when the coating layer of the concentrator is realized with left-handed materials, energy will circulate between the coating and the core, and the energy transmitted through the core of the concentrator can be much bigger than that transmitted through the concentrator. Therefore, such concentrator is also a power flux enhancer. Finally, we propose a spherical field rotator, which functions as not only a wave vector rotator but also a polarization rotator, depending on the orientations of the spherical rotator with respect to the incident wave direction. The functionality of these transformation devices are all successfully confirmed by our analytical full-wave method, which also provides an alternate computational efficient validation method in contrast to numerical validation methods.

156 citations

Journal ArticleDOI
TL;DR: The electromagnetic field solution for a spherical invisibility cloak with an active device inside is established, and the surface voltages due to an electric dipole inside the concealed region are found equal to the auxiliary scalar potentials at the inner boundary.
Abstract: The electromagnetic field solution for a spherical invisibility cloak with an active device inside is established. Extraordinary electric and magnetic surface voltages are induced at the inner boundary of a spherical cloak, which prevent electromagnetic waves from going out. The phase and handness of polarized waves obliquely incident on such boundaries are kept in the reflected waves. The surface voltages due to an electric dipole inside the concealed region are found equal to the auxiliary scalar potentials at the inner boundary, which consequently gain physical counterparts in this case.

125 citations

Journal ArticleDOI
TL;DR: Radio-frequency (RF) electromagnetic interactions with solid and liquid materials from the macroscale to the nanoscale is overviewed, and wavelength and material length scales required to define permittivity in materials are discussed.
Abstract: The goal of this paper is to overview radio-frequency (RF) electromagnetic interactions with solid and liquid materials from the macroscale to the nanoscale. The overview is geared toward the general researcher. Because this area of research is vast, this paper concentrates on currently active research areas in the megahertz (MHz) through gigahertz (GHz) frequencies, and concentrates on dielectric response. The paper studies interaction mechanisms both from phenomenological and fundamental viewpoints. Relaxation, resonance, interface phenomena, plasmons, the concepts of permittivity and permeability, and relaxation times are summarized. Topics of current research interest, such as negative-index behavior, noise, plasmonic behavior, RF heating, nanoscale materials, wave cloaking, polaritonic surface waves, biomaterials, and other topics are overviewed. Relaxation, resonance, and related relaxation times are overviewed. The wavelength and material length scales required to define permittivity in materials is discussed.

78 citations

Journal ArticleDOI
TL;DR: In this paper, coordinate transformation theory is used to realize substrates that can modify the emission of an embedded source, and it is shown that with proper transformation functions the energy radiated by a source embedded in these space variant media will be concentrated in a narrow beam.
Abstract: We use coordinate transformation theory to realize substrates that can modify the emission of an embedded source. Simulation results show that with proper transformation functions the energy radiated by a source embedded in these space variant media will be concentrated in a narrow beam. The thickness of the slab achieved with our transformations will no longer be restricted by the evanescent modes and the source can be placed at any position along the boundary of the substrate without affecting the radiation pattern. We also discuss the case where reduced parameters are used, which still performs well and is physically realizable.

66 citations

References
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Book
01 Jan 1983
TL;DR: In this paper, a Potpourri of Particles is used to describe surface modes in small Particles and the Angular Dependence of Scattering is shown to be a function of the size of the particles.
Abstract: BASIC THEORY. Electromagnetic Theory. Absorption and Scattering by an Arbitrary Particle. Absorption and Scattering by a Sphere. Particles Small Compared with the Wavelength. Rayleigh--Gans Theory. Geometrical Optics. A Potpourri of Particles. OPTICAL PROPERTIES OF BULK MATTER. Classical Theories of Optical Constants. Measured Optical Properties. OPTICAL PROPERTIES OF PARTICLES. Extinction. Surface Modes in Small Particles. Angular Dependence of Scattering. A Miscellany of Applications. Appendices. References. Index.

16,859 citations

Journal ArticleDOI
TL;DR: The authors' simulations show that a version of the lens operating at the frequency of visible light can be realized in the form of a thin slab of silver, which resolves objects only a few nanometers across.
Abstract: Optical lenses have for centuries been one of scientists’ prime tools. Their operation is well understood on the basis of classical optics: curved surfaces focus light by virtue of the refractive index contrast. Equally their limitations are dictated by wave optics: no lens can focus light onto an area smaller than a square wavelength. What is there new to say other than to polish the lens more perfectly and to invent slightly better dielectrics? In this Letter I want to challenge the traditional limitation on lens performance and propose a class of “superlenses,” and to suggest a practical scheme for implementing such a lens. Let us look more closely at the reasons for limitation in performance. Consider an infinitesimal dipole of frequency v in front of a lens. The electric component of the field will be given by some 2D Fourier expansion,

10,974 citations


"Peculiarities in the dielectric res..." refers background in this paper

  • ...And indeed,the present interest in so-called metamaterials which are being studied for their possible potential in microwave and higher-frequency imaging applications [ 4 ,5] are often based on the simultaneously negative permittivity and permeability parameters [6]....

    [...]

Journal ArticleDOI

10,495 citations


"Peculiarities in the dielectric res..." refers background in this paper

  • ...And indeed,the present interest in so-called metamaterials which are being studied for their possible potential in microwave and higher-frequency imaging applications [4,5] are often based on the simultaneously negative permittivity and permeability parameters [ 6 ]....

    [...]

Journal ArticleDOI
23 Jun 2006-Science
TL;DR: This work shows how electromagnetic fields can be redirected at will and proposes a design strategy that has relevance to exotic lens design and to the cloaking of objects from electromagnetic fields.
Abstract: Using the freedom of design that metamaterials provide, we show how electromagnetic fields can be redirected at will and propose a design strategy. The conserved fields-electric displacement field D, magnetic induction field B, and Poynting vector B-are all displaced in a consistent manner. A simple illustration is given of the cloaking of a proscribed volume of space to exclude completely all electromagnetic fields. Our work has relevance to exotic lens design and to the cloaking of objects from electromagnetic fields.

7,811 citations


"Peculiarities in the dielectric res..." refers background in this paper

  • ...The invisibility or at least low observability of scatterers with negative material parameter values has been studied also in the full-wave regime [8], and recent studies have appeared dealing with even a complete cloaking of arbitrary objects by tracing and dragging wave rays past it [9–12]....

    [...]

Journal ArticleDOI
06 Aug 2004-Science
TL;DR: Recent advances in metamaterials research are described and the potential that these materials may hold for realizing new and seemingly exotic electromagnetic phenomena is discussed.
Abstract: Recently, artificially constructed metamaterials have become of considerable interest, because these materials can exhibit electromagnetic characteristics unlike those of any conventional materials. Artificial magnetism and negative refractive index are two specific types of behavior that have been demonstrated over the past few years, illustrating the new physics and new applications possible when we expand our view as to what constitutes a material. In this review, we describe recent advances in metamaterials research and discuss the potential that these materials may hold for realizing new and seemingly exotic electromagnetic phenomena.

3,893 citations


"Peculiarities in the dielectric res..." refers background in this paper

  • ...And indeed,the present interest in so-called metamaterials which are being studied for their possible potential in microwave and higher-frequency imaging applications [4, 5 ] are often based on the simultaneously negative permittivity and permeability parameters [6]....

    [...]