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Yu Zhao, Ki-Chul Kwon, Munkh-Uchral Erdenebat, Md-Sifatul Islam, Seok-Hee Jeon, Nam Kim
The calculation of realistic full-color holographic displays is hindered by the high computational cost. Previously, we suggested a point cloud gridding (PCG) method to calculate monochrome holograms of real objects. In this research, a relocated point cloud gridding (R-PCG) method is proposed to enhance the reconstruction quality and accelerate the calculation speed in GPU for a full-color holographic system. We use a depth camera to acquire depth and color information from the real scene then reconstruct the point cloud model virtually...
May 20, 2018: Applied Optics
Kyuhwan Kim, Seung Hun Kim, Gyogwon Koo, Min Seok Seo, Sang Woo Kim
Holographic data storage (HDS) has attracted much attention as a next-generation storage medium. Because HDS suffers from two-dimensional (2D) inter-symbol interference (ISI), the partial-response maximum-likelihood (PRML) method has been studied to reduce 2D ISI. However, the PRML method has various drawbacks. To solve the problems, we propose a modified decision feedback equalizer (DFE) for HDS. To prevent the error propagation problem, which is a typical problem in DFEs, we also propose a reliability factor for HDS...
May 20, 2018: Applied Optics
Zhilong Jiang, Xingchen Pan, Yan Kong, Weiying Qian, Shouyu Wang, Cheng Liu
Because of the limited dynamic range of common detectors, high-frequency components weaker than the threshold of the detector used are lost in digital holography (DH) even with the aid of coherent diffraction imaging (CDI)-based iterative computation, and this makes DH less preferable for many interesting applications. To overcome this problem, the partially saturated diffraction pattern was adopted to enhance the resolution of DH iteratively. Since more high-frequency components were retrieved in comparison with our former CDI-based digital holographic method, the resolution of DH was improved further...
May 10, 2018: Applied Optics
Guy F de Téramond, Tianbo Liu, Raza Sabbir Sufian, Hans Günter Dosch, Stanley J Brodsky, Alexandre Deur
The structure of generalized parton distributions is determined from light-front holographic QCD up to a universal reparametrization function w(x) which incorporates Regge behavior at small x and inclusive counting rules at x→1. A simple ansatz for w(x) that fulfills these physics constraints with a single-parameter results in precise descriptions of both the nucleon and the pion quark distribution functions in comparison with global fits. The analytic structure of the amplitudes leads to a connection with the Veneziano model and hence to a nontrivial connection with Regge theory and the hadron spectrum...
May 4, 2018: Physical Review Letters
C Pin, J-B Jager, M Tardif, E Picard, E Hadji, F de Fornel, B Cluzel
Fourteen years ago, optical lattices and holographic tweezers were considered as a revolution, allowing for trapping and manipulating multiple particles at the same time using laser light. Since then, near-field optical forces have aroused tremendous interest as they enable efficient trapping of a wide range of objects, from living cells to atoms, in integrated devices. Yet, handling at will multiple objects using a guided light beam remains a challenging task for current on-chip optical trapping techniques...
May 18, 2018: Lab on a Chip
Antoine Iannessi, Pierre-Yves Marcy, Olivier Clatz, Anne-Sophie Bertrand, Maki Sugimoto
The digitalization of modern imaging has led radiologists to become very familiar with computers and their user interfaces (UI). New options for display and command offer expanded possibilities, but the mouse and keyboard remain the most commonly utilized, for usability reasons. In this work, we review and discuss different UI and their possible application in radiology. We consider two-dimensional and three-dimensional imaging displays in the context of interventional radiology, and discuss interest in touchscreens, kinetic sensors, eye detection, and augmented or virtual reality...
May 16, 2018: Insights Into Imaging
Lasma Alberte, Martin Ammon, Amadeo Jiménez-Alba, Matteo Baggioli, Oriol Pujolàs
We present a class of holographic massive gravity models that realize a spontaneous breaking of translational symmetry-they exhibit transverse phonon modes whose speed relates to the elastic shear modulus according to elasticity theory. Massive gravity theories thus emerge as versatile and convenient theories to model generic types of translational symmetry breaking: explicit, spontaneous, and a mixture of both. The nature of the breaking is encoded in the radial dependence of the graviton mass. As an application of the model, we compute the temperature dependence of the shear modulus and find that it features a glasslike melting transition...
April 27, 2018: Physical Review Letters
Andrea Amoretti, Daniel Areán, Blaise Goutéraux, Daniele Musso
In contrast to metals with weak disorder, the resistivity of weakly pinned charge density waves (CDWs) is not controlled by irrelevant processes relaxing momentum. Instead, the leading contribution is governed by incoherent, diffusive processes which do not drag momentum and can be evaluated in the clean limit. We compute analytically the dc resistivity for a family of holographic charge density wave quantum critical phases and discuss its temperature scaling. Depending on the critical exponents, the ground state can be conducting or insulating...
April 27, 2018: Physical Review Letters
Christoph A Agten, Cyrill Dennler, Andrea B Rosskopf, Laurenz Jaberg, Christian W A Pfirrmann, Mazda Farshad
OBJECTIVES: The aim of this study was to assess feasibility and accuracy of augmented reality-guided lumbar facet joint injections. MATERIALS AND METHODS: A spine phantom completely embedded in hardened opaque agar with 3 ring markers was built. A 3-dimensional model of the phantom was uploaded to an augmented reality headset (Microsoft HoloLens). Two radiologists independently performed 20 augmented reality-guided and 20 computed tomography (CT)-guided facet joint injections each: for each augmented reality-guided injection, the hologram was manually aligned with the phantom container using the ring markers...
May 8, 2018: Investigative Radiology
Xiao Xiang, Jihwan Kim, Michael J Escuti
Optical films and surfaces using geometric phase are increasingly demonstrating unique and sometimes enhanced performance compared to traditional elements employing propagation phase. Here, we report on a diffraction grating with wider angular bandwidth and significantly higher average first-order efficiency than the nearest prior art of metasurfaces, volume holographic gratings, and surface-relief gratings configured to achieve a steep deflection angle. More specifically, we demonstrate a liquid crystal (LC) polymer Bragg polarization grating (PG) with large angular bandwidth and high efficiency in transmission-mode for 532 nm wavelength and 400 nm period...
May 8, 2018: Scientific Reports
Xiaohu Zhang, Xiong Li, Jinjin Jin, Mingbo Pu, Xiaoliang Ma, Jun Luo, Yinghui Guo, Changtao Wang, Xiangang Luo
Composed of ultrathin metal or dielectric nanostructures, metasurfaces can manipulate the phase, amplitude and polarization of electromagnetic waves at a subwavelength scale, which is promising for flat optical devices. In general, metasurfaces composed of space-variant anisotropic units are sensitive to the incident polarization due to the inherent polarization dependent geometric phase. Here, we implement polarization-independent broadband metasurface holograms constructed by polarization-dependent anisotropic elliptical nanoholes by elaborate design of complex amplitude holograms...
May 8, 2018: Nanoscale
Yansheng Liang, Yanan Cai, Zhaojun Wang, Ming Lei, Zhiliang Cao, Yue Wang, Manman Li, Shaohui Yan, Piero R Bianco, Baoli Yao
Holographic optical tweezers are a powerful optical trapping and manipulation tool in numerous applications such as life science and colloidal physics. However, imperfections in the spatial light modulator and optical components of the system will introduce detrimental aberrations to the system, thereby degrading the trapping performance significantly. To address this issue, we develop an aberration correction technique by using a high-order vortex as the correction metric. The optimal Zernike polynomial coefficients for quantifying the system aberrations are determined by comparing the distorted vortex and the ideal one...
May 1, 2018: Applied Optics
Hongpeng Liu, Dan Yu, Ke Zhou, Shichan Wang, Suhua Luo, Weibo Wang, Qinggong Song
This publisher's note amends the funding section in Appl. Opt.56, 9006 (2017)APOPAI0003-693510.1364/AO.56.009006.
May 1, 2018: Applied Optics
Carles Soler, José Á Picazo-Bueno, Vicente Micó, Anthony Valverde, Daznia Bompart, Francisco J Blasco, Juan G Álvarez, Almudena García-Molina
Sperm motility is one of the most significant parameters in the prediction of male fertility. Until now, both motility analysis using an optical microscope and computer-aided sperm analysis (CASA-Mot) entailed the use of counting chambers with a depth to 20µm. Chamber depth significantly affects the intrinsic sperm movement, leading to an artificial motility pattern. For the first time, laser microscopy offers the possibility of avoiding this interference with sperm movement. The aims of the present study were to determine the different motility patterns observed in chambers with depths of 10, 20 and 100µm using a new holographic approach and to compare the results obtained in the 20-µm chamber with those of the laser and optical CASA-Mot systems...
May 4, 2018: Reproduction, Fertility, and Development
Mariam Bouhmadi-López, Ahmed Errahmani, Taoufik Ouali, Yaser Tavakoli
The background cosmological dynamics of the late Universe is analysed on the framework of a dark energy model described by an holographic Ricci dark energy component. Several kind of interactions between the dark energy and the dark matter components are considered herein. We solve the background cosmological dynamics for the different choices of interactions with the aim to analyse not only the current evolution of the universe but also its asymptotic behaviour and, in particular, possible future singularities removal...
2018: European Physical Journal. C, Particles and Fields
Delphine Coursault, Nishant Sule, John Parker, Ying Bao, Norbert F Scherer
The tremendous progress in nanoscience now allows creating static nanostructured materials for a broad range of applications. A further goal is to achieve dynamic and reconfigurable nanostructures. One approach involves nanoparticle-based optical matter, but so far studies have only considered spherical constituents. A non-trivial issue is that nanoparticles with other shapes are expected to have different local electromagnetic field distributions and interactions with neighbors in optical matter arrays. Therefore, one would expect their dynamics to be different as well...
May 2, 2018: Nano Letters
Tomasz Kozacki, Maksymilian Chlipala, Piotr L Makowski
We present an end-to-end full color Fourier holographic imaging approach, which involves standard holographic recording with three wavelengths and an improved LED-driven display. It provides almost undistorted orthoscopic reconstruction of large objects in full color, which can be viewed with a naked eye. High quality reconstruction is preserved across large object depths, measured in meters, as shown theoretically and experimentally. Our imaging approach is based on capture, processing and display of the object wave fields without spherical phase factors...
April 30, 2018: Optics Express
Juan Deng, Zile Li, Guoxing Zheng, Jin Tao, Qi Dai, Liangui Deng, Ping'an He, Qiling Deng, Qingzhou Mao
Metasurfaces consist of dielectric nanobrick arrays with different dimensions in the long and short axes can be used to generate different phase delays, predicting a new way to manipulate an incident beam in the two orthogonal directions separately. Here we demonstrate the concept of depth perception based three-dimensional (3D) holograms with polarization-independent metasurfaces. 4-step dielectric metasurfaces-based fan-out optical elements and holograms operating at 658 nm were designed and simulated. Two different holographic images with high fidelity were generated at the same plane in the far field for different polarization states...
April 30, 2018: Optics Express
F F Qin, Z Z Liu, Z Zhang, Q Zhang, J J Xiao
Due to the abilities of manipulating the wavefront of light with well-controlled amplitude, and phase and polarization, optical metasurfaces are very suitable for optical holography, enabling applications with multiple functionalities and high data capacity. Here, we demonstrate encoding two- and three-dimensional full-color holographic images by an ultrathin metasurface hologram whose unit cells are subwavelength nanoslits with spatially varying orientations. We further show that it is possible to achieve full-color holographic multiplexing with such kind of geometric metasurfaces, realized by a synthetic spectrum holographic algorithm...
April 30, 2018: Optics Express
Lianyan Li, Yuechun Shi, Yong Zhao, Yunshan Zhang, Wenxuan Wang, Yitao Wu, Yinli Zhou, Xing Zhang, Xiangfei Chen
A transverse Bragg resonance (TBR) waveguide semiconductor laser with sampled grating is proposed and analyzed. The transverse phase shift in the middle of the grating is realized by shifting half of the sampling period, resulting in a good single transverse mode resonance. The characteristics such as the modal gain, the electric field distribution, the near and far field beam patterns are theoretically studied. Since the sampled grating is designed by combining a uniform basic grating with a micrometer scale sampling pattern, it can be easily fabricated by holographic exposure and conventional photolithography with low cost...
April 30, 2018: Optics Express
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