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https://www.readbyqxmd.com/read/27906376/spin-hall-effect-of-transmitted-light-in-a-three-layer-waveguide-with-lossy-epsilon-near-zero-metamaterial
#1
Tingting Tang, Jie Li, Yanfen Zhang, Chaoyang Li, Li Luo
We study spin Hall effect (SHE) of transmitted light in a three-layer waveguide with epsilon-near-zero (ENZ) metamaterial. As the increased loss of anisotropic ENZ metamaterial brings decreased propagation loss for oblique incidence, the transmission of incident light is enhanced which induces a different distribution of transverse shift peaks. Based on simulation results, the influences of ENZ permittivity components and thickness as well as gold layer thickness on transverse shift of left-circularly polarized light in ENZ/Au/ENZ waveguide are analyzed...
November 28, 2016: Optics Express
https://www.readbyqxmd.com/read/27897165/nonreciprocity-and-magnetic-free-isolation-based-on-optomechanical-interactions
#2
Freek Ruesink, Mohammad-Ali Miri, Andrea Alù, Ewold Verhagen
Nonreciprocal components, such as isolators and circulators, provide highly desirable functionalities for optical circuitry. This motivates the active investigation of mechanisms that break reciprocity, and pose alternatives to magneto-optic effects in on-chip systems. In this work, we use optomechanical interactions to strongly break reciprocity in a compact system. We derive minimal requirements to create nonreciprocity in a wide class of systems that couple two optical modes to a mechanical mode, highlighting the importance of optically biasing the modes at a controlled phase difference...
November 29, 2016: Nature Communications
https://www.readbyqxmd.com/read/27893722/valley-photonic-crystals-for-control-of-spin-and%C3%A2-topology
#3
Jian-Wen Dong, Xiao-Dong Chen, Hanyu Zhu, Yuan Wang, Xiang Zhang
Photonic crystals offer unprecedented opportunity for light manipulation and applications in optical communication and sensing. Exploration of topology in photonic crystals and metamaterials with non-zero gauge field has inspired a number of intriguing optical phenomena such as one-way transport and Weyl points. Recently, a new degree of freedom, valley, has been demonstrated in two-dimensional materials. Here, we propose a concept of valley photonic crystals with electromagnetic duality symmetry but broken inversion symmetry...
November 28, 2016: Nature Materials
https://www.readbyqxmd.com/read/27886279/slowing-down-light-using-a-dendritic-cell-cluster-metasurface-waveguide
#4
Z H Fang, H Chen, F S Yang, C R Luo, X P Zhao
Slowing down or even stopping light is the first task to realising optical information transmission and storage. Theoretical studies have revealed that metamaterials can slow down or even stop light; however, the difficulty of preparing metamaterials that operate in visible light hinders progress in the research of slowing or stopping light. Metasurfaces provide a new opportunity to make progress in such research. In this paper, we propose a dendritic cell cluster metasurface consisting of dendritic structures...
November 25, 2016: Scientific Reports
https://www.readbyqxmd.com/read/27886230/controlling-the-electromagnetic-field-confinement-with-metamaterials
#5
Jordi Bonache, Gerard Zamora, Ferran Paredes, Simone Zuffanelli, Pau Aguilà, Ferran Martín
The definition of a precise illumination region is essential in many applications where the electromagnetic field should be confined in some specific volume. By using conventional structures, it is difficult to achieve an adequate confinement distance (or volume) with negligible levels of radiation leakage beyond it. Although metamaterial structures and metasurfaces are well-known to provide high controllability of their electromagnetic properties, this feature has not yet been applied to solve this problem...
November 25, 2016: Scientific Reports
https://www.readbyqxmd.com/read/27886208/flexible-controls-of-scattering-clouds-using-coding-metasurfaces
#6
Shuo Liu, Tie Jun Cui
Metamaterials or metasurfaces have been designed to precisely manipulate the scattering at every angle. Here, we propose to control the probability of random scattering appearing in the desired range of angles, which is defined in this letter as scattering cloud. We present a controllable random metasurface by simply adding a random coding sequence to gradient coding sequence. It is shown that the direction and size of the scattering cloud can be arbitrarily engineered. We demonstrate the exotic behavior of the scattering cloud by making an analogy to the electron cloud in quantum mechanics...
November 25, 2016: Scientific Reports
https://www.readbyqxmd.com/read/27885268/loss-induced-enhanced-transmission-in-anisotropic-density-near-zero-acoustic-metamaterials
#7
Chen Shen, Yun Jing
Anisotropic density-near-zero (ADNZ) acoustic metamaterials are investigated theoretically and numerically in this paper and are shown to exhibit extraordinary transmission enhancement when material loss is induced. The enhanced transmission is due to the enhanced propagating and evanescent wave modes inside the ADNZ medium thanks to the interplay of near-zero density, material loss, and high wave impedance matching in the propagation direction. The equi-frequency contour (EFC) is used to reveal whether the propagating wave mode is allowed in ADNZ metamaterials...
November 25, 2016: Scientific Reports
https://www.readbyqxmd.com/read/27883052/electrical-switching-in-semiconductor-metal-self-assembled-vo2-disordered-metamaterial-coatings
#8
Sunil Kumar, Francis Maury, Naoufal Bahlawane
As a strongly correlated metal oxide, VO2 inspires several highly technological applications. The challenging reliable wafer-scale synthesis of high quality polycrystalline VO2 coatings is demonstrated on 4" Si taking advantage of the oxidative sintering of chemically vapor deposited VO2 films. This approach results in films with a semiconductor-metal transition (SMT) quality approaching that of the epitaxial counterpart. SMT occurs with an abrupt electrical resistivity change exceeding three orders of magnitude with a narrow hysteresis width...
November 24, 2016: Scientific Reports
https://www.readbyqxmd.com/read/27876753/metamaterials-prime-time
#9
Andrea Alù
No abstract text is available yet for this article.
November 23, 2016: Nature Materials
https://www.readbyqxmd.com/read/27874082/ultra-broadband-reflective-metamaterial-with-rcs-reduction-based-on-polarization-convertor-information-entropy-theory-and-genetic-optimization-algorithm
#10
Si Jia Li, Xiang Yu Cao, Li Ming Xu, Long Jian Zhou, Huan Huan Yang, Jiang Feng Han, Zhao Zhang, Di Zhang, Xiao Liu, Chen Zhang, Yue Jun Zheng, Yi Zhao
We proposed an ultra-broadband reflective metamaterial with controlling the scattering electromagnetic fields based on a polarization convertor. The unit cell of the polarization convertor was composed of a three layers substrate with double metallic split-rings structure and a metal ground plane. The proposed polarization convertor and that with rotation angle of 90 deg had been employed as the "0" and "1" elements to design the digital reflective metamaterial. The numbers of the "0" and "1" elements were chosen based on the information entropy theory...
November 22, 2016: Scientific Reports
https://www.readbyqxmd.com/read/27874053/coherent-control-of-double-deflected-anomalous-modes-in-ultrathin-trapezoid-shaped-slit-metasurface
#11
Z Zhu, H Liu, D Wang, Y X Li, C Y Guan, H Zhang, J H Shi
Coherent light-matter interaction in ultrathin metamaterials has been demonstrated to dynamically modulate intensity, polarization and propagation direction of light. The gradient metasurface with a transverse phase variation usually exhibits an anomalous refracted beam of light dictated by so-called generalized Snell's law. However, less attention has been paid to coherent control of the metasurface with multiple anomalous refracted beams. Here we propose an ultrathin gradient metasurface with single trapezoid-shaped slot antenna as its building block that allows one normal and two deflected transmitted beams...
November 22, 2016: Scientific Reports
https://www.readbyqxmd.com/read/27869197/polarization-bandgaps-and-fluid-like-elasticity-in-fully-solid-elastic-metamaterials
#12
Guancong Ma, Caixing Fu, Guanghao Wang, Philipp Del Hougne, Johan Christensen, Yun Lai, Ping Sheng
Elastic waves exhibit rich polarization characteristics absent in acoustic and electromagnetic waves. By designing a solid elastic metamaterial based on three-dimensional anisotropic locally resonant units, here we experimentally demonstrate polarization bandgaps together with exotic properties such as 'fluid-like' elasticity. We construct elastic rods with unusual vibrational properties, which we denote as 'meta-rods'. By measuring the vibrational responses under flexural, longitudinal and torsional excitations, we find that each vibration mode can be selectively suppressed...
November 21, 2016: Nature Communications
https://www.readbyqxmd.com/read/27862423/active-photoswitching-of-sharp-fano-resonances-in-thz-metadevices
#13
Manukumara Manjappa, Yogesh Kumar Srivastava, Longqing Cong, Ibraheem Al-Naib, Ranjan Singh
Fano resonances offer exciting features in enhancing the non-linearity and sensing capabilities in metamaterial systems. An active photoswitching of Fano resonances in a terahertz metadevice at low optical pump powers is demonstrated, which signifies the extreme sensitivity of the high-quality-factor resonant electric field to the external light illumination.
November 14, 2016: Advanced Materials
https://www.readbyqxmd.com/read/27857381/finite-element-analysis-of-electromagnetic-waves-in-two-dimensional-transformed-bianisotropic-media
#14
Yan Liu, Boris Gralak, Sebastien Guenneau
We analyze the wave propagation in two-dimensional bianisotropic media with the Finite Element Method (FEM). Starting from the Maxwell-Tellegen's equations in bianisotropic media, we derive some system of coupled Partial Differential Equations (PDEs) for longitudinal electric and magnetic field components. These PDEs are implemented in FEM using a solid mechanics formulation. Perfectly Matched Layers (PMLs) are also discussed to model unbounded bianisotropic media. The PDEs and PMLs are then implemented in a finite element software, and transformation optics is further introduced to design some bianisotropic media with interesting functionalities, such as cloaks, concentrators and rotators...
November 14, 2016: Optics Express
https://www.readbyqxmd.com/read/27857361/probing-metamaterials-with-structured-light
#15
Yun Xu, Jingbo Sun, Wiktor Walasik, Natalia M Litchinitser
Photonic metamaterials and metasurfaces are nanostructured optical materials engineered to enable properties that have not been found in nature. Optical characterization of these structures is a challenging task. We report a reliable technique that is particularly useful for characterization of phase properties introduced by small and spatially inhomogeneous samples of metamaterials and metasurfaces. The proposed structured light, or vortex based interferometric method is used to directly visualize phase changes introduced by subwavelength-thick nanostructures...
November 14, 2016: Optics Express
https://www.readbyqxmd.com/read/27857221/metadevice-for-intensity-modulation-with-sub-wavelength-spatial-resolution
#16
Pablo Cencillo-Abad, Nikolay I Zheludev, Eric Plum
Effectively continuous control over propagation of a beam of light requires light modulation with pixelation that is smaller than the optical wavelength. Here we propose a spatial intensity modulator with sub-wavelength resolution in one dimension. The metadevice combines recent advances in reconfigurable nanomembrane metamaterials and coherent all-optical control of metasurfaces. It uses nanomechanical actuation of metasurface absorber strips placed near a mirror in order to control their interaction with light from perfect absorption to negligible loss, promising a path towards dynamic diffraction and focusing of light as well as holography without unwanted diffraction artefacts...
November 18, 2016: Scientific Reports
https://www.readbyqxmd.com/read/27834375/experimental-demonstration-of-anomalous-floquet-topological-insulator-for-sound
#17
Yu-Gui Peng, Cheng-Zhi Qin, De-Gang Zhao, Ya-Xi Shen, Xiang-Yuan Xu, Ming Bao, Han Jia, Xue-Feng Zhu
Time-reversal invariant topological insulator is widely recognized as one of the fundamental discoveries in condensed matter physics, for which the most fascinating hallmark is perhaps a spin-based topological protection, the absence of scattering of conduction electrons with certain spins on matter surface. Recently, it has created a paradigm shift for topological insulators, from electronics to photonics, phononics and mechanics as well, bringing about not only involved new physics but also potential applications in robust wave transport...
November 11, 2016: Nature Communications
https://www.readbyqxmd.com/read/27828509/design-of-triple-band-metamaterial-absorbers-with-refractive-index-sensitivity-at-infrared-frequencies
#18
Jie Xu, Ziyi Zhao, Haochi Yu, Le Yang, Peng Gou, Jun Cao, Yuexin Zou, Jie Qian, Tianjun Shi, Qijun Ren, Zhenghua An
A triple-band perfect plasmonic metamaterial absorber based on a metal/insulator/metal (MIM) structure is designed. A new freedom through tuning the thicknesses of each ring structures is introduced to realize a quasi-three-dimensional perfect absorber at three extinction wavelengths by using the finite difference time domain method. The physical machine is explained by the time domain field analyses and the coupled mode theory. The characteristics of the absorber make our proposed strategy applicable for the design of more general multiband and broadband perfect absorbers...
October 31, 2016: Optics Express
https://www.readbyqxmd.com/read/27828501/strong-coupling-of-localized-surface-plasmons-and-ensembles-of-dye-molecules
#19
V N Peters, T U Tumkur, Jing Ma, Nicholas A Kotov, M A Noginov
We have studied strong exciton-plasmon coupling in the films of Ag nanoislands as well as in the layer-by-layer (LBL) deposited films of Au nanoparticles (NPs) coated with highly concentrated rhodamine 6G (R6G) dye. Their absorbance and the reflectance spectra featured the peaks or dips, which were not characteristic of dye or NPs/nanoislands taken separately. The positions of the spectral maxima (or minima) in the dye-doped films, plotted against those in pristine Ag nanoislands films, resulted in the dispersion curves comprised of three branches...
October 31, 2016: Optics Express
https://www.readbyqxmd.com/read/27828457/graphene-metamaterial-modulator-for-free-space-thermal-radiation
#20
Kebin Fan, Jonathan Suen, Xueyuan Wu, Willie J Padilla
We proposed and demonstrated a new metamaterial architecture capable of high speed modulation of free-space space thermal infrared radiation using graphene. Our design completely eliminates channel resistance, thereby maximizing the electrostatic modulation speed, while at the same time effectively modulating infrared radiation. Experiment results verify that our device with area of 100 × 120 µm<sup>2</sup> can achieve a modulation speed as high as 2.6 GHz. We further highlight the utility of our graphene metamaterial modulator by reconstructing a fast infrared signal using an equivalent time sampling technique...
October 31, 2016: Optics Express
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