检索结果-内蒙古大学图书馆

Numerical Simulation of Surface-Enhanced Coherent Anti-Stokes Raman Scattering on Gold Nanoparticle Substrate

JOURNAL OF NANOSCIENCE AND NANOTECHNOLOGY 2017年第3期17卷 2152-2156页

作者： Zhou, Qian Zhu, Jianhua Yuan, Jinghe Fang, Xiaohong Sichuan Univ Dept Phys Chengdu 610064 Peoples R China Sichuan Univ Minist Educ Key Lab High Energy Dens Phys & Technol Chengdu 610064 Peoples R China Chinese Acad Sci Inst Chem Beijing 100190 Peoples R China

Surface-Enhanced Coherent Anti-Stokes Raman Scattering (SECARS) is an emerging surfaceenhanced spectroscopy, provides higher Raman sensitivity than Surface-Enhanced Raman Scattering (SERS). With Frequency-Dependent finite-difference time-domain method (FD-FDTD), we studied the enhancement effect of gold nanoparticle substrate on SECARS, and found the enhancement factor of SECARS with the optimized gold nanoparticle substrate can reach to 1016, which has 8 orders of magnitude higher than that of SERS, and the substrate structure optimized for SERS is not optimal for SECARS. This calculation supplies a new reference for designing the structures to enhance SECARS.

关键词： Surface-Enhanced Coherent Anti-Stokes Raman Scattering Surface-Enhanced Raman Scattering finite-difference time-domain method Gold Nanoparticles Substrate

来源：评论

学校读者我要写书评

暂无评论

Interplay between diffraction and the Pancharatnam-Berry phase in inhomogeneously twisted anisotropic media

引用

Physical Review A 2017年第2期95卷 023823-023823页

作者： Chandroth P. Jisha Alessandro Alberucci Lorenzo Marrucci Gaetano Assanto Centro de Física do Porto Faculdade de Ciências Universidade do Porto PT-4169-007 Porto Portugal Optics Laboratory Tampere University of Technology FI-33101 Tampere Finland NooEL - Nonlinear Optics and OptoElectronics Lab University “Roma Tre” IT-00146 Rome Italy Dipartimento di Fisica Università di Napoli Federico II IT-80100 Naples Italy CNR-ISASI Institute of Applied Science and Intelligent Systems IT-80078 Pozzuoli (NA) Italy CNR-ISC Institute for Complex Systems IT-00185 Rome Italy

We discuss the propagation of an electromagnetic field in an inhomogeneously anisotropic material where the optic axis is rotated in the transverse plane but is invariant along the propagation direction. In such a configuration, the evolution of an electromagnetic wave packet is governed by the Pancharatnam-Berry phase (PBP), which is responsible for the appearance of an effective photonic potential. In a recent paper [ACS Photon. 3, 2249 (2016)] we demonstrated that the effective potential supports transverse confinement. Here we find the profile of the quasimodes and show that the photonic potential arises from the Kapitza effect of light. The theoretical results are confirmed by numerical simulations, accounting for the medium birefringence. Finally, we analyze in detail a configuration able to support nonleaky guided modes.

关键词： Birefringence Classical optics Geometric & topological phases Geometrical & wave optics Optoelectronics Spin-orbit coupling Optical materials & elements finite-difference time-domain method Schroedinger equation

来源：评论

学校读者我要写书评

暂无评论

Transmission enhancement in loss-gain multilayers by resonant suppression of reflection

引用

Physical Review B 2017年第23期96卷 235129-235129页

作者： Denis V. Novitsky Vladimir R. Tuz Sergey L. Prosvirnin Andrei V. Lavrinenko Andrey V. Novitsky B. I. Stepanov Institute of Physics National Academy of Sciences of Belarus 68 Nezavisimosti Avenue Minsk 220072 Belarus ITMO University 49 Kronverksky Pr. St. Petersburg 197101 Russia International Center of Future Science State Key Laboratory on Integrated Optoelectronics College of Electronic Science and Engineering Jilin University 2699 Qianjin Str. Changchun 130012 China Institute of Radio Astronomy of National Academy of Sciences of Ukraine 4 Mystetstv Street Kharkiv 61002 Ukraine School of Radio Physics V.N. Karazin Kharkiv National University 4 Svobody sq. Kharkiv 61022 Ukraine DTU Fotonik Technical University of Denmark Ørsteds Plads 343 DK-2800 Kongens Lyngby Denmark Department of Theoretical Physics and Astrophysics Belarusian State University 4 Nezavisimosti Avenue Minsk 220030 Belarus

Using the transfer-matrix approach and solving time-domain differential equations, we analyze the loss compensation mechanism in multilayer systems composed of an absorbing transparent conductive oxide and dielectric doped with an active material. We reveal also another regime with the possibility of enhanced transmission with suppressed reflection originating from the resonant properties of the multilayers. For obliquely incident and evanescent waves, such enhanced transmission under suppressed reflection turns into the reflectionless regime, which is similar to that observed in the PT-symmetric structures, but does not require PT symmetry. We infer that the reflectionless transmission is due to the full loss compensation at the resonant wavelengths of the multilayers.

关键词： Hyperbolic metamaterials Light-matter interaction Nanophotonics Nonlinear optics Photonic crystals Plasmonics Quantum dots Effective medium approach finite-difference time-domain method Semiclassical methods Transfer matrix method

来源：评论

学校读者我要写书评

暂无评论

Driven optical matter: Dynamics of electrodynamically coupled nanoparticles in an optical ring vortex

引用

Physical Review E 2017年第2期95卷 022604-022604页

作者： Patrick Figliozzi Nishant Sule Zijie Yan Ying Bao Stanislav Burov Stephen K. Gray Stuart A. Rice Suriyanarayanan Vaikuntanathan Norbert F. Scherer Department of Chemistry The University of Chicago Chicago Illinois 60637 USA James Franck Institute The University of Chicago Chicago Illinois 60637 USA Center for Nanoscale Materials Argonne National Laboratory Lemont Illinois 60439 USA

To date investigations of the dynamics of driven colloidal systems have focused on hydrodynamic interactions and often employ optical (laser) tweezers for manipulation. However, the optical fields that provide confinement and drive also result in electrodynamic interactions that are generally neglected. We address this issue with a detailed study of interparticle dynamics in an optical ring vortex trap using 150-nm diameter Ag nanoparticles. We term the resultant electrodynamically interacting nanoparticles a driven optical matter system. We also show that a superior trap is created by using a Au nanoplate mirror in a retroreflection geometry, which increases the electric field intensity, the optical drive force, and spatial confinement. Using nanoparticles versus micron sized colloids significantly reduces the surface hydrodynamic friction allowing us to access small values of optical topological charge and drive force. We quantify a further 50% reduction of hydrodynamic friction when the nanoparticles are driven over the Au nanoplate mirrors versus over a mildly electrostatically repulsive glass surface. Further, we demonstrate through experiments and electrodynamics–Langevin dynamics simulations that the optical drive force and the interparticle interactions are not constant around the ring for linearly polarized light, resulting in a strong position-dependent variation in the nanoparticle velocity. The nonuniformity in the optical drive force is also manifest as an increase in fluctuations of interparticle separation, or effective temperature, as the optical driving force is increased. Finally, we resolve an open issue in the literature on periodic modulation of interparticle separation with comparative measurements of driven 300-nm-diameter polystyrene beads that also clearly reveal the significance of electrodynamic forces and interactions in optically driven colloidal systems. Therefore, the modulations in the optical forces and electrodynamic interactions th

关键词： Electromagnetic interactions Fluctuations & noise Vortex flows Charged colloids Nanoparticles Dark-field microscopy finite-difference time-domain method Langevin equation Optical tweezers

来源：评论

学校读者我要写书评

暂无评论

Topological photonics: From crystals to particles

引用

Physical Review B 2017年第4期96卷 041408(R)-041408(R)页

作者： Gleb Siroki Paloma A. Huidobro Vincenzo Giannini Department of Physics Imperial College London London SW7 2AZ United Kingdom Instituto de Estructura de la Materia IEM-CSIC E-28006 Madrid Spain

Photonic crystal topological insulators host protected states at their edges. In the band structure these edge states appear as continuous bands crossing the photonic band gap. They allow light to propagate unidirectionally and without scattering. In practice it is essential to make devices relying on these effects as miniature as possible. Here we study photonic topological insulator particles (finite crystals). In such particles the edge state frequencies are discrete. Nevertheless, the discrete states support pseudospin-dependent unidirectional propagation. They allow light to bend around sharp corners similarly to the continuous edge states and act as topologically protected whispering gallery modes, which can store and filter light as well as manipulate its angular momentum. Though we consider a particular all-dielectric realization that does not require a magnetic field, the results in the findings are general, explaining multiple experimental observations of discrete transmission peaks in photonic topological insulators.

关键词： Edge states Photonics Topological phases of matter Nanoparticles finite-difference time-domain method

来源：评论

学校读者我要写书评

暂无评论

Multimode directionality in all-dielectric metasurfaces

引用

Physical Review B 2017年第16期95卷 165426-165426页

作者： Yuanqing Yang Andrey E. Miroshnichenko Sarah V. Kostinski Mikhail Odit Polina Kapitanova Min Qiu Yuri S. Kivshar State Key Laboratory of Modern Optical Instrumentation College of Optical Science and Engineering Zhejiang University Hangzhou 310027 China Nonlinear Physics Center Research School of Physics and Engineering Australian National University Canberra ACT 2601 Australia Department of Physics Harvard University Cambridge Massachusetts 02138 USA Department of Nanophotonics and Metamaterials ITMO University St. Petersburg 197101 Russia

We demonstrate that spectrally diverse multiple magnetic dipole resonances can be excited in all-dielectric structures lacking rotational symmetry, in contrast to conventionally used spheres, disks, or spheroids. Such multiple magnetic resonances arise from hybrid Mie-Fabry-Perot modes, and can constructively interfere with induced electric dipole moments, thereby leading to novel multifrequency unidirectional scattering. Here we focus on elongated dielectric nanobars, whose magnetic resonances can be spectrally tuned by their aspect ratios. Based on our theoretical results, we suggest all-dielectric multimode metasurfaces and verify them in proof-of-principle microwave experiments. We also believe that the demonstrated property of multimode directionality is largely responsible for the best efficiency of all-dielectric metasurfaces that were recently shown to operate across multiple telecom bands.

关键词： Light propagation, transmission & absorption Metamaterials Mie scattering Nanoantennas Photonics Coatings Nanoparticles finite-difference time-domain method Plane-wave expansion

来源：评论

学校读者我要写书评

暂无评论

Lightning Surge Propagation Analysis in OHGW of Electrified High Speed Railway

引用

Energy Procedia 2017年 138卷 99-104页

作者： Kokiat Aodsup Thanatchai Kulworawanichpong School of Electrical Engineering Suranaree University of Technology Thailand

This paper proposes the analysis of the lightning surge propagation along overhead ground wires based on the telegraph equations which describe the voltage and current on a power transmission line and the finite difference time-domain (FDTD) method. The proposed FDTD method was tested with the 25-kV power transmission system of a high-speed railway in comparison with the solution obtained by using the Bewley method. From the results, after the travelling surge reaches the contact point between the overhead ground wire and the transmission pole, the surge is partially reflected and partially passes through. If the grounding resistance at a transmission pole is small, the peak of the reflected voltage surge is greater than that of the surge passing through. However, the higher value of grounding resistance causes the higher peak of the surge that passes through than the peak of the reflected surge. The computations show that the FDTD method is one of the most accurate methods to analyze lightning surge propagation in power transmission lines.

关键词： Surge propagation overhead ground wire finite-difference time-domain method lightning surge

来源：评论

学校读者我要写书评

暂无评论

Analysis of light leakage between the adjacent pixels in a color-filter stacked white OLED display

引用

DISPLAYS 2016年 45卷 6-13页

作者： Lee, Jong-Kwon Cho, Seunghyun Kang, Dong Wan Seoul Natl Univ Global Frontier Ctr Multiscale Energy Syst Seoul 151744 South Korea Daou InCube Display Business Unit Yongin 448547 Gyeonggi Do South Korea

We have investigated the effect of light leakage between the adjacent pixels on the electroluminescence (EL) intensity variation in a color filter (CF) stacked white organic light-emitting diode (OLED) display. It is found that light leakage of the white pixel adjacent to the emitting green pixel is the highest level, due to the shortened optical path and high transmittance of the white-CF layer. As the optical path between the adjacent pixels decreases, light-leakage induced EL intensity of the white or blue pixel increases, while there is no appreciable change in the EL intensity of the emitting green pixel. Also, the observed light leakage and the corresponding power spectrum highly increase as the orientation of emitted dipole sources is perpendicular to the interfaces of the layered structures. Therefore, the presented analysis of the light leakage in the CF stacked white OLED provides useful guidelines to improve the device performance for high-resolution OLED displays. (C) 2016 Elsevier B.V. All rights reserved.

关键词： OLED displays finite-difference time-domain method Light leakage Electroluminescence

来源：评论

学校读者我要写书评

暂无评论

A subwavelength metal-grating assisted sensor of Kretschmann style for investigating the sample with high refractive index

引用

Chinese Physics B 2016年第3期25卷 347-350页

作者：李旭峰彭伟赵亚丽王乔魏计林 School of Applied Science Taiyuan University of Science and TechnologyTaiyuan 030024China School of Physics and Optoelectronic Technology Dalian University of TechnologyDalian 116024China No.33 Research Institute of China Electronics Technology Group Corporation Taiyuan 030024China

In this paper, a subwavelength metal-grating assisted sensor of Kretschmann style that is capable of detecting the sample with a refractive index higher than that of the substrate is proposed. The sensor configuration is similar to the traditional Kretschmann structure, but the metal film is pattered into a grating. As a TM-polarized laser beam impinges from the substrate, a resonant dip point in reflectance curve is produced at a certain incident angle. Our studies indicate that the sensing sensitivity and resolution are affected by the grating＇s gap and period, and after these parameters havelaeen optimized, a sensing sensitivity of 51.484°/RIU is obtained with a slightly changing resolution.

关键词： surface plasmons sensing finite-difference time-domain method

来源：评论

学校读者我要写书评

暂无评论

Ultimate terahertz field enhancement of single nanoslits

引用

Physical Review B 2017年第7期95卷 075424-075424页

作者： Young-Mi Bahk Sanghoon Han Jiyeah Rhie Joohyun Park Hyeongtag Jeon Namkyoo Park Dai-Sik Kim Department of Physics and Astronomy and Center for Atom Scale Electromagnetism Seoul National University Seoul 08826 Korea Department of Nanoscale Semiconductor Engineering Hanyang University Seoul 04763 Korea Division of Materials Science and Engineering Hanyang University Seoul 04763 Korea Photonic Systems Laboratory Department of Electrical and Computer Engineering Seoul National University Seoul 08826 Korea

A single metallic slit is the simplest plasmonic structure for basic physical understanding of electromagnetic field confinement. By reducing the gap size, the field enhancement is expected to first go up and then go down when the gap width becomes subnanometer because of the quantum tunneling effects. A fundamental question is whether we reach the classical limit of field enhancement before entering the quantum regime, i.e., whether the quantum effects undercut the highest field enhancement classically possible. Here, by performing terahertz time domain spectroscopy on single slits of widths varying from 1.5 nm to 50 µm, we show that ultimate field enhancement determined by the wavelength of light and film thickness can be reached before we hit the quantum regime. Our paper paves way toward designing a quantum plasmonic system with maximum control yet without sacrificing the classical field enhancements.

关键词： Classical optics Electromagnetism Metamaterials Plasmonics Nanostructures finite-difference time-domain method Infrared spectroscopy

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：