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Showing papers on "Metamaterial published in 2010"


Journal ArticleDOI
TL;DR: The steep dispersion of the Fano resonance profile promises applications in sensors, lasing, switching, and nonlinear and slow-light devices.
Abstract: Since its discovery, the asymmetric Fano resonance has been a characteristic feature of interacting quantum systems. The shape of this resonance is distinctively different from that of conventional symmetric resonance curves. Recently, the Fano resonance has been found in plasmonic nanoparticles, photonic crystals, and electromagnetic metamaterials. The steep dispersion of the Fano resonance profile promises applications in sensors, lasing, switching, and nonlinear and slow-light devices.

3,536 citations


Journal ArticleDOI
TL;DR: In this article, an ultrathin, wide-angle, subwavelength high performance metamaterial absorber for optical frequencies is presented. But the experimental results show that an absorption peak of 88% is achieved at the wavelength of ∼1.58μm, though theoretical results give near perfect absorption.
Abstract: High absorption efficiency is particularly desirable at present for various microtechnological applications including microbolometers, photodectors, coherent thermal emitters, and solar cells. Here we report the design, characterization, and experimental demonstration of an ultrathin, wide-angle, subwavelength high performance metamaterial absorber for optical frequencies. Experimental results show that an absorption peak of 88% is achieved at the wavelength of ∼1.58 μm, though theoretical results give near perfect absorption.

1,147 citations


Journal ArticleDOI
TL;DR: A planar metamaterial analogue of electromagnetically induced transparency at optical frequencies is experimentally demonstrated and yields a sensitivity of 588 nm/RIU and a figure of merit of 3.8.
Abstract: We experimentally demonstrate a planar metamaterial analogue of electromagnetically induced transparency at optical frequencies. The structure consists of an optically bright dipole antenna and an optically dark quadrupole antenna, which are cut-out structures in a thin gold film. A pronounced coupling-induced reflectance peak is observed within a broad resonance spectrum. A metamaterial sensor based on these coupling effects is experimentally demonstrated and yields a sensitivity of 588 nm/RIU and a figure of merit of 3.8.

1,130 citations


Journal ArticleDOI
TL;DR: The potential of transformation optics to create functionalities in which the optical properties can be designed almost at will is reviewed, which can be used to engineer various optical illusion effects, such as the invisibility cloak.
Abstract: Transformation optics describes the capability to design the path of light waves almost at will through the use of metamaterials that control effective materials properties on a subwavelength scale. In this review, the physics and applications of transformation optics are discussed.

1,085 citations


Journal ArticleDOI
TL;DR: This work demonstrates, for the first time, a spatially dependent metamaterial perfect absorber operating in the infrared regime, and achieves an experimental absorption of 97% at a wavelength of 6.0 μm.
Abstract: We demonstrate, for the first time, a spatially dependent metamaterial perfect absorber operating in the infrared regime We achieve an experimental absorption of 97% at a wavelength of 60 microns, and our results agree well with numerical full-wave simulations By using two different metamaterial sublattices we experimentally demonstrate a spatial and frequency varying absorption which may have many relevant applications including hyperspectral sub-sampling imaging

1,045 citations


Journal ArticleDOI
05 Aug 2010-Nature
TL;DR: It is experimentally demonstrated that the incorporation of gain material in the high-local-field areas of a metamaterial makes it possible to fabricate an extremely low-loss and active optical NIM.
Abstract: Much research activity is being devoted to the design and fabrication of metamaterials, artificially tailored composites with the counter-intuitive optical property of a negative refraction index. There is an exciting and wide range of possible applications that could be developed with such negative-index materials, including invisibility cloaks and 'perfect' lenses, but a major hurdle is that the performance is severely limited by absorption losses. Vladimir Shalaev and colleagues now demonstrate an approach that could lead to a breakthrough in this area; they have incorporated an optical gain medium within the metamaterial as a way to compensate the intrinsic loss, and show that optical pumping leads to a significantly improved negative refraction index and performance-related figure-of-merit at visible wavelengths. The study confirms that it is possible to design an optical metamaterial that is not limited by the intrinsic loss of its metal constituent. Metamaterials have the counterintuitive optical property of negative refraction index. They have a wide range of possible applications, including 'invisibility cloaks' and perfect lenses, but their performance is severely limited by absorption losses. These authors have incorporated an optical gain medium within a metamaterial as a way to compensate the intrinsic loss, and show that optical pumping leads to a significantly improved negative refraction index and figure of merit within the 722–738-nm visible wavelength range. The recently emerged fields of metamaterials and transformation optics promise a family of exciting applications such as invisibility, optical imaging with deeply subwavelength resolution and nanophotonics with the potential for much faster information processing. The possibility of creating optical negative-index metamaterials (NIMs) using nanostructured metal–dielectric composites has triggered intense basic and applied research over the past several years1,2,3,4,5,6,7,8,9,10. However, the performance of all NIM applications is significantly limited by the inherent and strong energy dissipation in metals, especially in the near-infrared and visible wavelength ranges11,12. Generally the losses are orders of magnitude too large for the proposed applications, and the reduction of losses with optimized designs seems to be out of reach. One way of addressing this issue is to incorporate gain media into NIM designs13,14,15,16. However, whether NIMs with low loss can be achieved has been the subject of theoretical debate17,18. Here we experimentally demonstrate that the incorporation of gain material in the high-local-field areas of a metamaterial makes it possible to fabricate an extremely low-loss and active optical NIM. The original loss-limited negative refractive index and the figure of merit (FOM) of the device have been drastically improved with loss compensation in the visible wavelength range between 722 and 738 nm. In this range, the NIM becomes active such that the sum of the light intensities in transmission and reflection exceeds the intensity of the incident beam. At a wavelength of 737 nm, the negative refractive index improves from −0.66 to −1.017 and the FOM increases from 1 to 26. At 738 nm, the FOM is expected to become macroscopically large, of the order of 106. This study demonstrates the possibility of fabricating an optical negative-index metamaterial that is not limited by the inherent loss in its metal constituent.

745 citations


Journal ArticleDOI
27 Feb 2010-Science
TL;DR: In this paper, the authors demonstrate a form of memory capacitance which interfaces metamaterials with a class of devices known collectively as memory devices, and demonstrate electrically-controlled persistent frequency tuning of a metammaterial, allowing lasting modification of its response using a transient stimulus.
Abstract: The resonant elements that grant metamaterials their unique properties have the fundamental limitation of restricting their useable frequency bandwidth The development of frequency-agile metamaterials has helped to alleviate these bandwidth restrictions by allowing real-time tuning of the metamaterial frequency response We demonstrate electrically-controlled persistent frequency tuning of a metamaterial, allowing lasting modification of its response using a transient stimulus This work demonstrates a form of memory capacitance which interfaces metamaterials with a class of devices known collectively as memory devices

739 citations


Journal Article
01 Jan 2010-Physics
TL;DR: The experimental realization and theoretical understanding of a membrane-type acoustic metamaterial with very simple construct, capable of breaking the mass density law of sound attenuation in the 100-1000 Hz regime by a significant margin are presented.
Abstract: We present the experimental realization and theoretical explanation of a membrane-type acoustic metamaterial of very simple structure,capable of breaking the mass density law of sound attenuation in the 100—1000Hz regime by a significant margin(~200 times).Due to the membrane's weak elastic moduli,low frequency oscillation patterns can be found even in a small elastic film with fixed boundaries defined by a rigid grid.The vibrational eigenfrequencies can be tuned by placing a small mass at the center of the membrane sample.Near-total reflection is achieved at a frequency in between two eigenmodes where the in-plane average of the normal displacement is zero.By using finite element simulations,a negative dynamic mass is explicitly demonstrated at frequencies around the total reflection frequency.Excellent agreement between theory and experiment is obtained.We also show that the present mechanism can explain the phenomenon of total microwave transmission through subwavelength slits in metallic fractals,at frequencies intermediate between two local resonances.

696 citations


Journal ArticleDOI
TL;DR: It is demonstrated how powerful emerging techniques in the field of transformation optics can be used to harness the flexibility of gradient index materials for imaging applications to achieve a new class of optical devices.
Abstract: One of the more promising uses of metamaterials is in imaging, where the capability to control the propagation of light could lead to new applications. In particular, the realization of a broadband metamaterial lens that has an almost complete hemispherical field of view that is focused on a flat plane represents a significant step towards such new uses.

613 citations


Journal ArticleDOI
TL;DR: In this paper, the effect of the surface resistance of the FSS and dielectric substrate characteristics on the input impedance of the absorber is discussed by means of a circuital model.
Abstract: High-impedance surfaces (HIS) comprising lossy frequency selective surfaces (FSS) are employed to design thin electromagnetic absorbers. The structure, despite its typical resonant behavior, is able to perform a very wideband absorption in a reduced thickness. Losses in the frequency selective surface are introduced by printing the periodic pattern through resistive inks and hence avoiding the typical soldering of a large number of lumped resistors. The effect of the surface resistance of the FSS and dielectric substrate characteristics on the input impedance of the absorber is discussed by means of a circuital model. It is shown that the optimum value of surface resistance is affected both by substrate parameters (thickness and permittivity) and by FSS element shape. The equivalent circuit model is then used to introduce the working principles of the narrowband and the wideband absorbing structure and to derive the best-suited element for wideband absorption.

612 citations


Journal ArticleDOI
30 Apr 2010-Science
TL;DR: This paper presents metamaterials, artificial media structured on a size scale smaller than the wavelength of external stimuli, which enable us to design the authors' own “atoms” and thus access new functionalities, such as invisibility and imaging, with unlimited resolution.
Abstract: Metamaterials are artificial media structured on a size scale smaller than the wavelength of external stimuli. Whereas conventional materials derive their electromagnetic characteristics from the properties of atoms and molecules, metamaterials enable us to design our own “atoms” and thus access new functionalities, such as invisibility and imaging, with unlimited resolution.

Journal ArticleDOI
TL;DR: A three-dimensional chiral optical metamaterial is experimentally demonstrated that exhibits an asymmetric transmission for forwardly and backwardly propagating linearly polarized light.
Abstract: We experimentally demonstrate a three-dimensional chiral optical metamaterial that exhibits an asymmetric transmission for forwardly and backwardly propagating linearly polarized light. The observation of this novel effect requires a metamaterial composed of three-dimensional chiral meta-atoms without any rotational symmetry. Our analysis is supported by a systematic investigation of the transmission matrices for arbitrarily complex, generally lossy media that allows deriving a simple criterion for asymmetric transmission in an arbitrary polarization base. Contrary to physical intuition, in general the polarization eigenstates in such three-dimensional and low-symmetry metamaterials do not obey fixed relations and the associated transmission matrices cannot be symmetrized.

Journal ArticleDOI
TL;DR: In this paper, an improved algorithm for extracting the effective constitutive parameters of a metamaterial is derived, which invokes the Kramers-Kronig relations to ensure the uniqueness of the solution.
Abstract: In this paper, an improved algorithm for extracting the effective constitutive parameters of a metamaterial is derived. The procedure invokes the Kramers-Kronig relations to ensure the uniqueness of the solution. The accuracy of the method is demonstrated by retrieving the effective material parameters of a homogeneous slab. This study reveals under which conditions the calculation of the refractive index involves more than one branch of the complex logarithmic function. A metamaterial built up from wires and split-ring resonators is then investigated. The applicability and limits of the presented algorithm are explored by observing how the effective parameters of a metamaterial slab converge as its thickness is increased.

Journal ArticleDOI
TL;DR: The first practical implementation of a fully 3D broadband and low-loss ground-plane cloak at microwave frequencies is realized, realized by drilling inhomogeneous holes in multi-layered dielectric plates.
Abstract: Optical cloaking has already been demonstrated in two dimensions, and also in three dimensions for a limited range of angles. Now, Ma and Cui present a metamaterial-based cloaking device that can shield an object lying on the ground plane from all viewing angles at microwave frequencies.

Journal ArticleDOI
TL;DR: It is shown that all periodic metamaterials may be divided into five different classes only and how to deduce these five classes from symmetry considerations and provide a simple algorithm that can be applied to decide to which class a given meetamaterial belongs by measuring only the transmitted intensities.
Abstract: By relying on an advanced Jones calculus, we analyze the polarization properties of light upon propagation through metamaterial slabs in a comprehensive manner. Based on symmetry considerations, we show that all periodic metamaterials may be divided into five different classes only. It is shown that each class differently affects the polarization of the transmitted light and sustains different eigenmodes. We show how to deduce these five classes from symmetry considerations and provide a simple algorithm that can be applied to decide to which class a given metamaterial belongs by measuring only the transmitted intensities.

Journal ArticleDOI
TL;DR: In this paper, the authors show that thin membrane-type acoustic metamaterials can serve as a total reflection nodal surface at certain frequencies, which implies that several membrane panels can be stacked to achieve broad-frequency effectiveness.
Abstract: We show experimentally that thin membrane-type acoustic metamaterials can serve as a total reflection nodal surface at certain frequencies. The small decay length of the evanescent waves at these frequencies implies that several membrane panels can be stacked to achieve broad-frequency effectiveness. We report the realization of acoustic metamaterial panels with thickness ≤15 mm and weight ≤3 kg/m2 demonstrating 19.5 dB of internal sound transmission loss (STL) at around 200 Hz, and stacked panels with thickness ≤60 mm and weight ≤15 kg/m2 demonstrating an average STL of >40 dB over a broad range from 50 to 1000 Hz.

Journal ArticleDOI
TL;DR: A compliant metamaterial with tunability of Δλ ∼ 400 nm, greater than the resonant line width at optical frequencies is reported, using high-strain mechanical deformation of an elastomeric substrate to controllably modify the distance between the resonan elements.
Abstract: Metamaterial designs are typically limited to operation over a narrow bandwidth dictated by the resonant line width. Here we report a compliant metamaterial with tunability of Δλ ∼ 400 nm, greater than the resonant line width at optical frequencies, using high-strain mechanical deformation of an elastomeric substrate to controllably modify the distance between the resonant elements. Using this compliant platform, we demonstrate dynamic surface-enhanced infrared absorption by tuning the metamaterial resonant frequency through a CH stretch vibrational mode, enhancing the reflection signal by a factor of 180. Manipulation of resonator components is also used to tune and modulate the Fano resonance of a coupled system.

Journal ArticleDOI
TL;DR: The design, realization and measurement of a three-dimensional approximate transformation-optics lens in the microwave frequency band is shown, made of non-resonant metamaterials, which are fabricated with multilayered dielectric plates by drilling inhomogeneous holes.
Abstract: Lenses with superior performance with respect to conventional uniform materials are desirable. The authors show a three-dimensional lens, made of multilayered metamaterials and based on approximate transformation optics, which works in different polarizations at broad viewing angles and with wide bandwidth.

Journal ArticleDOI
TL;DR: The photonic density of states (PDOS) is one of the key physical quantities governing a variety of phenom- ena and hence PDOS manipulation is the route to new photonic devices.
Abstract: The photonic density of states (PDOS), like its' electronic coun- terpart, is one of the key physical quantities governing a variety of phenom- ena and hence PDOS manipulation is the route to new photonic devices. The PDOS is conventionally altered by exploiting the resonance within a device such as a microcavity or a bandgap structure like a photonic crystal. Here we show that nanostructured metamaterials with hyperbolic dispersion can dramatically enhance the photonic density of states paving the way for metamaterial based PDOS engineering.

Journal ArticleDOI
TL;DR: The photonic density of states (PDOS) is one of the key physical quantities governing a variety of phenomena and hence PDOS manipulation is the route to new photonic devices as mentioned in this paper.
Abstract: The photonic density of states (PDOS), like its electronic counterpart, is one of the key physical quantities governing a variety of phenomena and hence PDOS manipulation is the route to new photonic devices. The PDOS is conventionally altered by exploiting the resonance within a device such as a microcavity or a bandgap structure like a photonic crystal. Here we show that nanostructured metamaterials with hyperbolic dispersion can dramatically enhance the photonic density of states paving the way for metamaterial-based PDOS engineering.

Journal ArticleDOI
TL;DR: In this paper, a bilayered chiral metamaterial is proposed to realize a 90° polarization rotator, whose giant optical activity is due to the transverse magnetic dipole coupling among the metallic wire pairs of enantiomeric patterns.
Abstract: A bilayered chiral metamaterial is proposed to realize a 90° polarization rotator, whose giant optical activity is due to the transverse magnetic dipole coupling among the metallic wire pairs of enantiomeric patterns. By transmission through this thin bilayered structure of less than λ/30 thick, a linearly polarized wave is converted to its cross polarization with a resonant polarization conversion efficiency of over 90%. It is demonstrated that the chirality in the propagation direction makes this efficient cross-polarization conversion possible.

Journal ArticleDOI
TL;DR: This work presents ultra-broad-band metamaterial thin film with colossal dynamic control range, fulfilling present day research demands, and realizes the full potential of the thin film technology for long wavelength applications.
Abstract: Unusual performances of metamaterials such as negative index of refraction, memory effect, and cloaking originate from the resonance features of the metallic composite atom1−6. Indeed, control of metamaterial properties by changing dielectric environments of thin films below the metallic resonators has been demonstrated7−11. However, the dynamic control ranges are still limited to less than a factor of 10,7−11 with the applicable bandwidth defined by the sharp resonance features. Here, we present ultra-broad-band metamaterial thin film with colossal dynamic control range, fulfilling present day research demands. Hybridized with thin VO2 (vanadium dioxide)(12-18) films, nanoresonator supercell arrays designed for one decade of spectral width in terahertz frequency region show an unprecedented extinction ratio of over 10000 when the underlying thin film experiences a phase transition. Our nanoresonator approach realizes the full potential of the thin film technology for long wavelength applications.

Journal ArticleDOI
TL;DR: Evidence of an anomalously high density of photonic states in hyperbolic metamaterials is observed, which demonstrates the feasibility of an earlier-predicted single-photon gun, and paves the road for the use of metammaterials in quantum optics.
Abstract: We have observed, in metamaterial with hyperbolic dispersion (an array of silver nanowires in alumina membrane), a sixfold reduction of the emission lifetime of dye deposited onto the metamaterial’s surface. This serves as evidence of an anomalously high density of photonic states in hyperbolic metamaterials, demonstrates the feasibility of an earlier-predicted single-photon gun, and paves the road for the use of metamaterials in quantum optics.

Journal ArticleDOI
TL;DR: The bulk self-alignment of dispersed gold nanorods imposed by the intrinsic cylindrical micelle self-assembly in nematic and hexagonal liquid crystalline phases of anisotropic fluids results in a switchable polarization-sensitive plasmon resonance exhibiting stark differences from that of the same nanorod in isotropic fluids.
Abstract: We demonstrate the bulk self-alignment of dispersed gold nanorods imposed by the intrinsic cylindrical micelle self-assembly in nematic and hexagonal liquid crystalline phases of anisotropic fluids. External magnetic field and shearing allow for alignment and realignment of the liquid crystal matrix with the ensuing long-range orientational order of well-dispersed plasmonic nanorods. This results in a switchable polarization-sensitive plasmon resonance exhibiting stark differences from that of the same nanorods in isotropic fluids. The device-scale bulk nanoparticle alignment may enable optical metamaterial mass production and control of properties arising from combining the switchable nanoscale structure of anisotropic fluids with the surface plasmon resonance properties of the plasmonic nanorods.

Journal ArticleDOI
TL;DR: A novel approach of antireflection coating using metamaterials dramatically reduces the reflection and greatly enhances the transmission near a specifically designed frequency over a wide range of incidence angles for both transverse magnetic and transverse electric polarizations.
Abstract: We present a novel approach of antireflection coating using metamaterials. It dramatically reduces the reflection and greatly enhances the transmission near a specifically designed frequency over a wide range of incidence angles for both transverse magnetic and transverse electric polarizations. A classical interference mechanism is identified through analytical derivations and numerical simulations. It elucidates that the tailored magnitude and phase of waves reflected and transmitted at boundaries of metamaterial coating are responsible for the antireflection.

Journal ArticleDOI
TL;DR: Coupled split-ring-resonator metamaterials are completely eliminate linear birefringence and obtained pure optical activity and connected circular optical dichroism.
Abstract: Coupled split-ring-resonator metamaterials have previously been shown to exhibit large coupling effects, which are a prerequisite for obtaining large effective optical activity. By a suitable lateral arrangement of these building blocks, we completely eliminate linear birefringence and obtain pure optical activity and connected circular optical dichroism. Experiments around a 100 THz frequency and corresponding modeling are in good agreement. Rotation angles of about 30 degrees for 205 nm sample thickness are derived.

Journal ArticleDOI
TL;DR: In this paper, the frequency shift of a narrowband Fano resonance mode in a plasmonic planar metamaterial induced by a change in the dielectric properties of an adjacent chalcogenide glass layer was demonstrated.
Abstract: We demonstrate an innovative concept for nanoscale electro-optic switching. It exploits the frequency shift of a narrow-band Fano resonance mode in a plasmonic planar metamaterial induced by a change in the dielectric properties of an adjacent chalcogenide glass layer. An electrically stimulated transition between amorphous and crystalline forms of the glass brings about a 150 nm shift in the near-infrared resonance providing transmission modulation with a contrast ratio of 4:1 in a device of subwavelength thickness.

Journal ArticleDOI
TL;DR: In this article, a bilayered chiral metamaterial (CMM) is proposed to realize a 90 degree polarization rotator, whose giant optical activity is due to the transverse magnetic dipole coupling among the metallic wire pairs of enantiomeric patterns.
Abstract: A bilayered chiral metamaterial (CMM) is proposed to realize a 90 degree polarization rotator, whose giant optical activity is due to the transverse magnetic dipole coupling among the metallic wire pairs of enantiomeric patterns. By transmission through this thin bilayered structure of less than \lambda/30 thick, a linearly polarized wave is converted to its cross polarization with a resonant polarization conversion efficiency (PCE) of over 90%. Meanwhile, the axial ratio of the transmitted wave is better than 40 dB. It is demonstrated that the chirality in the propagation direction makes this efficient cross-polarization conversion possible. The transversely isotropic property of this polarization rotator is also experimentally verified. The optical activity of the present structure is about 2700 degree/\lambda, which is the largest optical activity that can be found in literature.

Journal ArticleDOI
TL;DR: The intricate interplay between different coupling effects in a plasmon hybridization picture provides a useful tool to intuitively understand the evolution from molecule-like states to solid-state-like bands.
Abstract: Metamaterials have become one of the hottest fields of photonics since the pioneering work of John Pendry on negative refractive index, invisibility cloaking, and perfect lensing. Three-dimensional metamaterials are required for practical applications. In these materials, coupling effects between individual constituents play a dominant role for the optical and electronic properties. Metamaterials can show both electric and magnetic responses at optical frequencies. Thus, electric as well as magnetic dipolar and higher-order multipolar coupling is the essential mechanism. Depending on the structural composition, both longitudinal and transverse coupling occur. The intricate interplay between different coupling effects in a plasmon hybridization picture provides a useful tool to intuitively understand the evolution from molecule-like states to solid-state-like bands.

Journal ArticleDOI
TL;DR: It is shown that appropriate placing of optically pumped laser dyes (gain) into the metamaterial structure results in a frequency band where the nonbianisotropic meetamaterial becomes amplifying and the figure of merit diverges at two distinct frequency points.
Abstract: On the basis of a full-vectorial three-dimensional Maxwell-Bloch approach we investigate the possibility of using gain to overcome losses in a negative refractive index fishnet metamaterial. We show that appropriate placing of optically pumped laser dyes (gain) into the metamaterial structure results in a frequency band where the nonbianisotropic metamaterial becomes amplifying. In that region both the real and the imaginary part of the effective refractive index become simultaneously negative and the figure of merit diverges at two distinct frequency points.