The Experts below are selected from a list of 100404 Experts worldwide ranked by ideXlab platform
Xiang Zhang - One of the best experts on this subject based on the ideXlab platform.
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three dimensional optical Metamaterial with a negative refractive index
Nature, 2008Co-Authors: Jason Valentine, Shuang Zhang, Thomas Zentgraf, Erick Ulinavila, Dentcho A Genov, Guy Bartal, Xiang ZhangAbstract:Metamaterials are artificially engineered structures that have properties, such as a negative refractive index, not attainable with naturally occurring materials. Negative-index Metamaterials (NIMs) were first demonstrated for microwave frequencies, but it has been challenging to design NIMs for optical frequencies and they have so far been limited to optically thin samples because of significant fabrication challenges and strong energy dissipation in metals. Such thin structures are analogous to a monolayer of atoms, making it difficult to assign bulk properties such as the index of refraction. Negative refraction of surface plasmons was recently demonstrated but was confined to a two-dimensional waveguide. Three-dimensional (3D) optical Metamaterials have come into focus recently, including the realization of negative refraction by using layered semiconductor Metamaterials and a 3D magnetic Metamaterial in the infrared frequencies; however, neither of these had a negative index of refraction. Here we report a 3D optical Metamaterial having negative refractive index with a very high figure of merit of 3.5 (that is, low loss). This Metamaterial is made of cascaded 'fishnet' structures, with a negative index existing over a broad spectral range. Moreover, it can readily be probed from free space, making it functional for optical devices. We construct a prism made of this optical NIM to demonstrate negative refractive index at optical frequencies, resulting unambiguously from the negative phase evolution of the wave propagating inside the Metamaterial. Bulk optical Metamaterials open up prospects for studies of 3D optical effects and applications associated with NIMs and zero-index materials such as reversed Doppler effect, superlenses, optical tunnelling devices, compact resonators and highly directional sources.
Lloyd C. l. Hollenberg - One of the best experts on this subject based on the ideXlab platform.
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Reconfigurable quantum Metamaterials
Optics Express, 2011Co-Authors: James Q. Quach, Andrew M. Martin, Chun-hsu Su, Andrew D. Greentree, Lloyd C. l. HollenbergAbstract:By coupling controllable quantum systems into larger structures we introduce the concept of a quantum Metamaterial. Conventional meta-materials represent one of the most important frontiers in optical design, with applications in diverse fields ranging from medicine to aerospace. Up until now however, Metamaterials have themselves been classical structures and interact only with the classical properties of light. Here we describe a class of dynamic Metamaterials, based on the quantum properties of coupled atom-cavity arrays, which are intrinsically lossless, reconfigurable, and operate fundamentally at the quantum level. We show how this new class of Metamaterial could be used to create a reconfigurable quantum superlens possessing a negative index gradient for single photon imaging. With the inherent features of quantum superposition and entanglement of Metamaterial properties, this new class of dynamic quantum Metamaterial, opens a new vista for quantum science and technology.
Emmanuel Rousseau - One of the best experts on this subject based on the ideXlab platform.
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All-Optical Photonic Band Control in a Quantum Metamaterial
Annalen der Physik, 2017Co-Authors: Didier Felbacq, Emmanuel RousseauAbstract:Metamaterials made of periodic collections of dielectric nanorods are considered theoretically. When quantum resonators are embedded within the nanorods, one obtains a quantum Metamaterial, whose electromagnetic properties depend upon the state of the quantum resonators. The theoretical model predicts that when the resonators are pumped and reach the inversion regime, the quantum Metamaterial exhibits an all-optical switchable conduction band. The phenomenon can be described by considering the pole stucture of the scattering matrix of the Metamaterial.
S. Radha - One of the best experts on this subject based on the ideXlab platform.
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Structure Metallic Surface for Terahertz Plasmonics
Plasmonics, 2019Co-Authors: E. Manikandan, S. Sasi Princy, B. S. Sreeja, S. RadhaAbstract:Plasmonics is the field of study of the interaction between incident light and electrons in metals. It is used widely for developing nanophotonic devices. The structured metallic surface such as Metamaterials can be used to produce spoof surface plasmons at any frequencies with the dimensions of unit cell less than the incident wavelength. Terahertz plasmonics is attracted to the field of research since it is used for sensing biological components even in a weak environment. The issue with planar Metamaterials is a lower quality factor value. Several methods have been adopted for obtaining high Q-value in Metamaterials. Among them, Fano- and Toroidal-based Metamaterials offer high Q-factor and string localized field enhancement. This article discusses the importance and developments in the field of high-Q terahertz Metamaterial for plasmonics applications. The nonlinear responses of terahertz Metamaterial under high-intense THz pulses are also discussed.
N I Zheludev - One of the best experts on this subject based on the ideXlab platform.
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Nano-optomechanical Metamaterials
2018Co-Authors: Dimitrios Papas, Eric Plum, Artemios Karvounis, N I ZheludevAbstract:The development of Metamaterials has led to demonstrations of fascinating optical properties such as negative refraction, invisibility, ultra-thin lenses and many more. However, the unique properties of Metamaterials are usually fixed and narrowband. Here we develop nano-optomechanical Metamaterials that offer a flexible platform for static and fast dynamic control of Metamaterial optical properties using electrostatic, magnetic, optical forces and ultrasound.
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Reconfiguring photonic Metamaterials
2012Co-Authors: Eric Plum, Jianfa Zhang, João Valente, N I ZheludevAbstract:Dynamic control over Metamaterial optical properties is key for the use of Metamaterials as active elements ranging from modulators and switches to tunable filters and programmable transformation optics devices. Here we exploit that the properties of virtually any Metamaterial structure strongly depend on the spatial arrangement of its components. By manufacturing plasmonic Metamaterials on a grid of elastic dielectric bridges of nanoscale thickness, we are able to dynamically rearrange sub-micron sized plasmonic building blocks across the entire Metamaterial array (see figure). We demonstrate that this approach provides a flexible platform for continuous tuning, fast modulation and high-contrast switching of photonic Metamaterials via external stimuli such as electric voltages, optical excitation and magnetic fields.
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Micromachined tunable Metamaterials: a review
Journal of Optics, 2012Co-Authors: Ai Qun Liu, Weiming Zhu, Din Ping Tsai, N I ZheludevAbstract:This paper reviews micromachined tunable Metamaterials, whereby the tuning capabilities are based on the mechanical reconfiguration of the lattice and/or the Metamaterial element geometry. The primary focus of this review is the feasibility of the realization of micromachined tunable Metamaterials via structure reconfiguration and the current state of the art in the fabrication technologies of structurally reconfigurable Metamaterial elements. The micromachined reconfigurable microstructures not only offer a new tuning method for Metamaterials without being limited by the nonlinearity of constituent materials, but also enable a new paradigm of reconfigurable Metamaterial-based devices with mechanical actuations. With recent development in nanomachining technology, it is possible to develop structurally reconfigurable Metamaterials with faster tuning speed, higher density of integration and more flexible choice of the working frequencies.
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Metamaterial analog of electromagnetically induced transparency
Physical Review Letters, 2008Co-Authors: N Papasimakis, N I Zheludev, V A Fedotov, S L ProsvirniAbstract:We demonstrate a classical analog of electromagnetically induced transparency in a planar Metamaterial. We show that pulses propagating through such Metamaterials experience considerable delay. The thickness of the structure along the direction of wave propagation is much smaller than the wavelength, which allows successive stacking of multiple Metamaterial slabs leading to increased transmission and bandwidth.
