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Muka Moriyama, Kejia Cao, Satoko Ogata, Kyoko Ohno-Matsui
AIMS: To analyse the characteristics of posterior vortex veins detected in highly myopic eyes by wide-field indocyanine green angiography (ICGA). METHODS: One hundred and fifty-eight consecutive patients (302 eyes) with high myopia (myopic refractive error >8.0 dioptres (D) or axial length ≥26.5 mm) were studied. Wide-field ICGA was performed with the Spectralis HRA module. RESULTS: Posterior vortex veins were found in 80 eyes (26%)...
January 18, 2017: British Journal of Ophthalmology
Tomoya Horide, Fumitake Kametani, Satoru Yoshioka, Takanori Kitamura, Kaname Matsumoto
Intriguing properties of self-organized nanocomposites of perovskite oxides are usually derived from the complex interface of constituent material phases. A sophisticated control of such a system is required for a broad range of energy and device applications, which demand a comprehensive understanding of the interface at the atomic scale. Here, we visualized and theoretically modeled the highly elastically strained nanorod, the interface region with misfit dislocations and heterointerface distortion, and the matrix with strain-induced oxygen vacancies in the self-organized YBa2Cu3O7-δ nanocomposite films with Ba perovskite nanorods...
January 17, 2017: ACS Nano
Shuang Zheng, Jian Wang
Measuring orbital angular momentum (OAM) states of vortex beams is of great importance in diverse applications employing OAM-carrying vortex beams. We present a simple and efficient scheme to measure OAM states (i.e. topological charge values) of vortex beams with annular gratings. The magnitude of the topological charge value is determined by the number of dark fringes after diffraction, and the sign of the topological charge value is distinguished by the orientation of the diffraction pattern. We first theoretically study the diffraction patterns using both annular amplitude and phase gratings...
January 17, 2017: Scientific Reports
Storm E Weiner, Marios C Tsatsos, Lorenz S Cederbaum, Axel U J Lode
Vortices are essential to angular momentum in quantum systems such as ultracold atomic gases. The existence of quantized vorticity in bosonic systems stimulated the development of the Gross-Pitaevskii mean-field approximation. However, the true dynamics of angular momentum in finite, interacting many-body systems like trapped Bose-Einstein condensates is enriched by the emergence of quantum correlations whose description demands more elaborate methods. Herein we theoretically investigate the full many-body dynamics of the acquisition of angular momentum by a gas of ultracold bosons in two dimensions using a standard rotation procedure...
January 16, 2017: Scientific Reports
Olivier Emile, Janine Emile
Michelson interferometry is one of the most widely used techniques for accuracy measurements. Its main characteristic feature is to infer a displacement in one of the arms of the interferometer from a phase measurement. Two different twisted beams, also called vortex beams, with opposite twisted rotations in each arm of the interferometer interfere in a daisy flower-like pattern. The number of petals is twice the topological charge. Their position depends on the relative phase of the beams. Naked eye detection of 44 pm displacements is achieved...
January 15, 2017: Optics Letters
Alessio D'Errico, Maria Maffei, Bruno Piccirillo, Corrado de Lisio, Filippo Cardano, Lorenzo Marrucci
Optical singularities manifesting at the center of vector vortex beams are unstable, since their topological charge is higher than the lowest value permitted by Maxwell's equations. Inspired by conceptually similar phenomena occurring in the polarization pattern characterizing the skylight, we show how perturbations that break the symmetry of radially symmetric vector beams lead to the formation of a pair of fundamental and stable singularities, i.e. points of circular polarization. We prepare a superposition of a radial (or azimuthal) vector beam and a uniformly linearly polarized Gaussian beam; by varying the amplitudes of the two fields, we control the formation of pairs of these singular points and their spatial separation...
January 12, 2017: Scientific Reports
John Mangeri, Yomery Espinal, Andrea Jokisaari, S Pamir Alpay, Serge Nakhmanson, Olle Heinonen
Composite materials comprised of ferroelectric nanoparticles in a dielectric matrix are being actively investigated for a variety of functional properties attractive for a wide range of novel electronic and energy harvesting devices. However, the dependence of these functionalities on shapes, sizes, orientation and mutual arrangement of ferroelectric particles is currently not fully understood. In this study, we utilize a time-dependent Ginzburg-Landau approach combined with coupled-physics finite-element-method based simulations to elucidate the behavior of polarization in isolated spherical PbTiO3 or BaTiO3 nanoparticles embedded in a dielectric medium, including air...
January 11, 2017: Nanoscale
Xu-Dong Bai, Xian-Ling Liang, Yun-Tao Sun, Peng-Cheng Hu, Yu Yao, Kun Wang, Jun-Ping Geng, Rong-Hong Jin
Recently, vortex beam carrying orbital angular momentum (OAM) for radio communications has attracted much attention for its potential of transmitting multiple signals simultaneously at the same frequency, which can be used to increase the channel capacity. However, most of the methods for getting multi-mode OAM radio beams are of complicated structure and very high cost. This paper provides an effective solution of generating dual circularly-polarized (CP) dual-mode OAM beams. The antenna consists of four dual-CP elements which are sequentially rotated 90 degrees in the clockwise direction...
January 10, 2017: Scientific Reports
G Thirunavukkarasu, M Mousley, M Babiker, J Yuan
Electron vortex beams constitute the first class of matter vortex beams which are currently routinely produced in the laboratory. Here, we briefly review the progress of this nascent field and put forward a natural quantum basis set which we show is suitable for the description of electron vortex beams. The normal modes are truncated Bessel beams (TBBs) defined in the aperture plane or the Fourier transform of the transverse structure of the TBBs (FT-TBBs) in the focal plane of a lens with the said aperture...
February 28, 2017: Philosophical Transactions. Series A, Mathematical, Physical, and Engineering Sciences
Benjamin J McMorran, Amit Agrawal, Peter A Ercius, Vincenzo Grillo, Andrew A Herzing, Tyler R Harvey, Martin Linck, Jordan S Pierce
The surprising message of Allen et al. (Allen et al. 1992 Phys. Rev. A 45, 8185 (doi:10.1103/PhysRevA.45.8185)) was that photons could possess orbital angular momentum in free space, which subsequently launched advancements in optical manipulation, microscopy, quantum optics, communications, many more fields. It has recently been shown that this result also applies to quantum mechanical wave functions describing massive particles (matter waves). This article discusses how electron wave functions can be imprinted with quantized phase vortices in analogous ways to twisted light, demonstrating that charged particles with non-zero rest mass can possess orbital angular momentum in free space...
February 28, 2017: Philosophical Transactions. Series A, Mathematical, Physical, and Engineering Sciences
Zhangming Mao, Peng Li, Mengxi Wu, Hunter Bachman, Nicolas Mesyngier, Xiasheng Guo, Sheng Liu, Francesco Costanzo, Tony Jun Huang
Focusing and enriching submicrometer and nanometer scale objects is of great importance for many applications in biology, chemistry, engineering, and medicine. Here, we present an acoustofluidic chip that can generate single vortex acoustic streaming inside a glass capillary through using low-power acoustic waves (only 5 V is required). The single vortex acoustic streaming that is generated, in conjunction with the acoustic radiation force, is able to enrich submicrometer- and nanometer-sized particles in a small volume...
January 9, 2017: ACS Nano
Linjia Su, Song Hu, Li Zhang, Zhuoran Wang, Weiping Gao, Jing Yuan, Minghua Liu
The synthesis and surface modification of gold nanorods (GNRs) is one of the most important and basic issues in nanoscience. Most of the widely investigated GNRs are coated with a cetyltrimethylammonium bromide(CTAB) bilayer. Here, a highly efficient method is proposed to replace CTAB from the surface of GNRs with a bifunctional 11-mercaptoundecanoic acid in order to decrease the possible toxicity caused by CTAB. This ligand exchange is achieved in a biphasic mixture of an aqueous solution and a water-immiscible ionic liquid (IL), [BMIM][Tf2 N]...
January 9, 2017: Small
Zhongliang Jiang, Bingzhao Xia, Ralph McBride, John Oakey
Cell encapsulation within photopolymerized polyethylene glycol (PEG)-based hydrogel scaffolds has been demonstrated as a robust strategy for cell delivery, tissue engineering, regenerative medicine, and developing in vitro platforms to study cellular behavior and fate. Strategies to achieve spatial and temporal control over PEG hydrogel mechanical properties, chemical functionalization, and cytocompatibility have advanced considerably in recent years. Recent microfluidic technologies have enabled the miniaturization of PEG hydrogels, thus enabling the fabrication of miniaturized cell-laden vehicles...
January 7, 2017: Journal of Materials Chemistry. B, Materials for Biology and Medicine
Ting-Wei Chen, Shih-Da Jheng, T F Jiang, Szu-Cheng Cheng
The dynamics of an exciton-polariton condensate (EPC) subject to harmonic confinement can cause spontaneously formed vortices to arrange into a triangular vortex lattice. The stability of such a spontaneously formed vortex lattice is still unknown. We investigate the quantum fluctuations of vortex lattices in a rapidly rotating EPC with a rotation frequency close to the harmonic trap. In such a large condensate, we find that a vortex lattice with a triangular structure is stable, whereas one with a square structure becomes unstable...
January 6, 2017: Journal of Physics. Condensed Matter: An Institute of Physics Journal
Jaffer M Kattan, Juan Carlos Serna-Ojeda, Anushree Sharma, Eung K Kim, Arturo Ramirez-Miranda, Marisa Cruz-Aguilar, Aleck E Cervantes, Ricardo F Frausto, Juan Carlos Zenteno, Enrique O Graue-Hernandez, Anthony J Aldave
PURPOSE: To describe 2 unrelated families with multiple members demonstrating a less commonly recognized vortex pattern of corneal deposits confirmed to be granular corneal dystrophy type 1 (GCD1) after identification of the p.(Arg555Trp) mutation in the transforming growth factor β-induced gene (TGFBI). METHODS: A slit-lamp examination was performed on individuals from 2 families, one of Mexican descent and a second of Italian descent. After DNA extraction from affected individuals and their unaffected relatives, TGFBI screening was performed...
February 2017: Cornea
Qiyao Liu, Bin Zhang, Sisheng Qi, Yaocheng Li, Xuliang Fan, Yongguang Zhao, Wei Zhou, Deyuan Shen
Using a home-made black phosphorus plate (BPP) as handedness controller and Q-switch modulator synchronously, a ~1.6 µm pulsed vortex laser with well-determined handedness is demonstrated in this letter. Stable vortex pulses of LG<sub>0, + 1</sub>, LG<sub>0,-1</sub>, LG<sub>0, + 2</sub> and LG<sub>0,-2</sub> modes were respectively achieved from compact resonant cavities in this experiment. Such pulsed vortex laser should have promising applications in various fields based on its simple structure, controllable handedness, and carried orbital angular momentum...
December 26, 2016: Optics Express
Moritsugu Sakamoto, Tomoyuki Sasaki, Tran Mien Tien, Kohei Noda, Nobuhiro Kawatsuki, Hiroshi Ono
In this study, we investigated the spatial light modulation properties of an optical vortex (OV) generator consisting of azo-dye-doped polymer liquid crystal (ADDLC) and a vector beam illuminator, focusing on flexibility and achromaticity for generating OVs. Uniaxially aligned ADDLC forms three-dimensional photoinduced twisted anisotropic structures under vector beam illumination, and can generate high-order OVs with even-numbered topological charges that correspond to the polarization pattern of the illuminating vector beam...
December 20, 2016: Applied Optics
Victor V Kotlyar, Alexey A Kovalev, Alexey P Porfirev
We theoretically study a Gaussian optical beam with an embedded off-axis optical vortex. We also experimentally generate such an asymmetric Gaussian optical vortex by using an off-axis spiral phase plate. It is shown that depending on the shift distance the laser beam has the form of a crescent, which is rotated upon propagation. An analytical expression is obtained for the orbital angular momentum of such a beam, which appears to be fractional. When the shift increases, the greater the number of spirality of the phase plate or the "fork" hologram, the slower the momentum decreases...
January 1, 2017: Optics Letters
Haixiang Ma, Xinzhong Li, Yuping Tai, Hehe Li, Jingge Wang, Miaomiao Tang, Yishan Wang, Jie Tang, Zhaogang Nie
We propose a method to determine the topological charge (TC) of a perfect vortex. With the phase shift technique, the perfect vortex and its conjugate beam exactly overlap and interfere. Consequently, the TC of a perfect vortex is determined by counting the number of interference fringes. This proposed method enables in situ determination of the TC of the perfect vortex without the need for additional optical elements, and it is immune to environmental vibration and parasitic interference.
January 1, 2017: Optics Letters
Amalya Minasyan, Clément Trovato, Jérôme Degert, Eric Freysz, Etienne Brasselet, Emmanuel Abraham
We propose a topological beam-shaping strategy of terahertz (THz) beams using geometric phase elements made of space-variant birefringent slabs. Quasi-monochromatic THz vortex beams are produced and characterized both in amplitude and phase from the reconstructed real-time two-dimensional imaging of the electric field. Nonseparable superpositions of such vortex beams are also obtained and characterized by two-dimensional polarimetric analysis. These results emphasize the versatility of the spin-orbit electromagnetic toolbox to prepare on-demand structured light endowed with polarization-controlled orbital angular momentum content in the THz domain, which should find many uses in future THz technologies...
January 1, 2017: Optics Letters
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