Negative refractive index in chiral metamaterials shuang zhang,1 yongshik park,1 jensen li,1 xinchao lu,2 weili zhang,2 and xiang zhang1,3, 1nanoscale science and engineering center, university of california, 5 etcheverry hall, berkeley, california 947201740, usa. The application of negative refractive index metamaterials. Jun 29, 2018 a strategy to greatly broaden negative refractive index nri band, reduce loss and ease bianisotropy of nri metamaterials mms has been proposed at terahertz frequencies. A chiral material slab can focus the incident em beams and can be used as a perfect lens4,5. The refractive index is retrieved from direct phase and amplitude measurements for transmission and reflection, which are all in. Optical negativeindex metamaterials purdue engineering. With their potential for spectacular applications, like superlensing and cloaking, metamaterials are a powerful class of nanostructured materials. Resonant negative refractive index metamaterials 173. Reconfigurability is achieved by cladding thin layers of liquid crystal both as a superstrate and a substrate on an established negative index metamaterial, and adjusting the permittivity of the liquid crystal. Negative refractive index metamaterials nrm are artificial composites, characteri zed by subwavelength features and negative effective value of re fractive index 2, 3.
Negative refractive index metamaterials come in two basic designs, namely those based on purely dielectric periodic structures 7, 9, 10, or as periodic metallic microstructures exhibiting electric 11, 12andmagnetic resonances 4, 1418. Negative refractive index in artificial metamaterials. At the interface of positive index medium and negative index medium, light. Negative refractive index in artificial metamaterials a. Negative index metamaterial or negative index material nim is a metamaterial whose refractive index for an electromagnetic wave has a negative value over some frequency range. Among the fascinating properties is a negative refractive index.
Negative refractive index metamaterials infrared nanooptics of. The index of refraction of the first and second media is denoted by n 1 and n 2 respectively, and. Negative refractive index and metamaterials free download as powerpoint presentation. This new class of negativeindex materials is relatively easy to fabricate on the nanoscale and. Refraction at an interface is commonly described by n the refractive index and we can show that causality forces us to choose a negative sign for the refractive index when both h. Realization of broadband negative refraction in visible range. Hence in a negative refractive index material, light makes a negative angle. Optical negative refraction in bulk metamaterials of.
Fan,4 federico capasso,4 and franco nori1,5 1advanced science institute, the institute of physical and chemical research riken, saitama 3510198, japan 2institute for theoretical and applied electrodynamics, russian academy of science, 125412 moscow, russia. The refractive index determines the amount by which the beam is deflected. The realization of a negative refractive index at such a high frequency range mainly originates from lowloss magnetic resonance and interactions between the neighboring functional layers. Refraction at an interface is commonly described by n the refractive index and we can show that causality forces us to choose a negative sign for the refractive index when both h and p are negative. In addition to a negative index ni of refraction, properties such as artificial magnetism2, negative permittivity, and negative permeability have been observed in. In conclusion, for an array of pairs of parallel gold rods, we obtained a negative refractive index of n. Negativeindex materials nims have a negative refractive index so that electromagnetic waves in such media propagate in a direction opposite to the flow of energy, which is indeed unusual and counterintuitive. In 2005, the first near field superlens which exceeded the diffraction limit was manufactured 9. Recently, metamaterials that display negative refractive index a property not found in any known naturally occurring material have drawn significant scientific interest, underscoring the remarkable potential of metamaterials to facilitate new developments in electromagnetism. Yet, the allowed range of material response does not preclude us from considering a medium for which both.
Grigorenko department of physics and astronomy, university of manchester, manchester, m 9pl, uk we discuss optical constants in artificial metamaterials showing negative magnetic permeability and electric permittivity and suggest a simple formula for the. Light absorber based on nanospheres on a substrate reflector. Pdf on jul 1, 2009, arvind vengurlekar and others published metamaterials with negative refractive index find, read and cite all the. The foms for such materials have been calculated12,20 to be signi. Nearinfrared metamaterials that possess a reconfigurable index of refraction from negative through zero to positive values are presented. Pdf metamaterials with negative refractive index researchgate. On the contrary, metamaterials are built of socalled artificial or metaatoms fig. If the index is positive, the exiting beam is deflected to the opposite side of the surface normal, whereas if the index is negative, the exiting beam is deflected the same side of the normal fig. Negative refractive index metamaterial structure using srr by.
Layered superconductors as negativerefractiveindex. For normal incidence, the light intensity only decays. Osa liquid crystal clad nearinfrared metamaterials with. This extension was developped by schelkunoff and the analogy between. Negative index of refraction in optical metamaterials. A freestanding, multilayered fishnet metamaterial is reported to experimentally exhibit a negative refractive index in the greenlight spectral range. Aug 15, 2008 the phase refractive index of the metamaterial remains positive, in contrast to that of lefthanded metamaterials 1, 4. Introduction metamaterial is a composite structure made of metals and dielectrics. Emmms exhibit exotic properties not easily achieved using naturally occurring materials. Surface current j0 in x x0 radiating in the medium negative refraction angle in a subsequent experiment8. All these applications rely on the metamaterials acting as a homogeneous material. Metamaterials composed of nanostructures of artificial atoms have shown many extraordinary properties that cannot be found in natural materials 1,2. These artificial dielectrics metamaterials consist of loosely coupled unit cells comprised of thin wire strips and split ring resonators to synthesize negative permittivity and permeability, respectively 24.
High negative refractive index in chiral metamaterials. All materials in nature have a positive refractive index. Layered superconductors as negativerefractiveindex metamaterials a. Recently negative index materials nims and photonic crystals pcs are getting more and more attention because of its extraordinary optical properties like near. Negative refractive index metamaterials from inherently nonmagnetic materials 3719 2. Resonant negative refractive index metamaterials 3 fig.
It has been shown that backward waves exist in chiral media1,3. Among the most soughtafter properties of metamaterials is the negative index of refraction. All known transparent materials possess a positive index because. Negative index materials nims, one of the most interesting applications of metamaterials, were first proposed by veselago in 1960s.
Physics and applications of negative refractive index materials. Ii smolyaninov, yj hung, and cc davis, pdfphysics 0610230. Negative refractive index metamaterials supporting 2d waves. The greatest potential of metamaterials is the possibility to create a structure with a negative refractive index, since this property is not found in any nonsynthetic material. 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. Note that the parallel component of wave vector is always preserved in transmission, but that energy flow is opposite to the wave vector. One of the most interesting of these is the ability to achieve superlensingthat is, to focus or image beyond the diffraction limit 7. The metamaterial used as a metallic mesh of thin wires for obtaining negative value of. Pdf high negative refractive index in chiral metamaterials. Part of the contents of this chapter has been published in mrs bull. Recently, chiral metamaterials were proposed as an alternative to realize negative refractive index. Negative refractive index metamaterial structure using srr. Osa freestanding optical negativeindex metamaterials of. Threedimensional optical metamaterial with a negative refractive index article pdf available in nature 4557211.
Metamaterials with negative refractive index article in journal of optical technology cc of opticheskii zhurnal 754. A wave travels more slowly in a medium such as glass or water by a factor of n. Recently, metamaterials that display negative refractive index a property not found in any known naturally occurring material have drawn significant scientific interest, underscoring the. However, artificially designed materials metamaterials can act as nims. Negative index materials nims have a negative refractive index so that electromagnetic waves in such media propagate in a direction opposite to the flow of energy, which is indeed unusual and counterintuitive.
Chiral metamaterials are metamaterials made of unit cells without symmetry planes. Jin dai, fei ye, yiting chen, mamoun muhammed, min qiu, min yan. Osa negative index of refraction in optical metamaterials. Download negative refraction metamaterials download. He predicted that a hypothetic material where both. The application of negative refractive index metamaterials to mm and submm wavelength instrumentation a thesis submitted to the university of manchester for the degree of doctor of philosophy in the faculty of engineering and physical sciences 20 imran mohamed school of. Ii smolyaninov, yj hung, and cc davis, pdfphysics0610230. When frequency dispersion exists, the energy wmust be written in a different manner. In 1967, he predicted the possibility of materials with a negative refractive index which would bend light the wrong way see diagram, opposite. Chapter 1 negative refractive index metamaterials in. This book is devoted to the description of metamaterials, their origins and physical principles, their electromagnetic and optical properties, as well as to.
Pdf metamaterials with negative permeability and negative. Metamaterials and negative refractive index science. Negative refractive index in chiral metamaterials shuang zhang,1 yongshik park,1 jensen li,1 xinchao lu,2 weili zhang,2 and xiang zhang1,3, 1nanoscale science and engineering center, university of california, 5 etcheverry hall, berkeley, california 947201740, usa 2school of electrical and computer engineering, oklahoma state university, stillwater, oklahoma 74078, usa. Metamaterials with negative refraction may lead to. Metamaterials metamaterials are artificial materials engineered to have properties that may not be found in nature.
H2 7 this expression is positive for a very broad class of dispersion equations for. We investigate a negative index metamaterial with a phasesensitive nearfield microscope and measure the optical phase as a function of distance. Tunable negative refractive index metamaterials based on thermochromic oxides. In addition to a negative index ni of refraction, properties such as artificial magnetism2, negative permittivity, and negative permeability have. Recently, artificially constructed metamaterials have become of considerable interest, because these materials can exhibit electromagnetic characteristics unlike those of any conventional materials. Negative refractive index and acoustic superlens from. Metamaterials, that is, artifi cial materials with rationally designed properties, can allow both fi eld components of light to be coupled to metaatoms, enabling entirely new optical properties and exciting applications with such twohanded light. A doubleperiodic array of pairs of parallel gold nanorods is shown to have a negative refractive index in the optical range. In this paper, we propose a novel structure of metamaterials, unit cell of complementary split ring resonators. This originates from the lefthanded behaviourthe property of. Negative refractive index and metamaterials metamaterial. A broadband tunable terahertz negative refractive index. Pdf negative refractive index in chiral metamaterials. The refractive index is one of the most fundamental characteristics of light propagation in materials.
Their work led to an explosion of interest in the field. Metamaterial negative refractive index has numerous applications such as mnri for antennas 16, superlens 17, and wireless power transfer 18 and for biomedical applications 1926. Metamaterials, negative refractive index, left handed material, scattering parameters 1. As mentioned above, a negative refractive index has not been found in naturally occurring materials due to the limitations imposed on their properties by their constituent components. Realization of broadband negative refraction in visible. Grigorenko department of physics and astronomy, university of manchester, manchester, m 9pl, uk we discuss optical constants in artificial metamaterials showing negative magnetic permeability and. In 2004, the first superlens with a negative refractive index provided resolution three times better than the diffraction limits and was manufactured at microwave frequencies. Effective medium approach the essential part in the study of the proposed metamaterial is the effective medium approach which will provide us with the effective permittivities and permeabilities. Abstract metamaterials, manmade composite media structured on a scale much smaller than a wavelength, offer surprising possibilities for engineering the propagation of waves 1,2,3,4,5,6.
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