检索结果-内蒙古大学图书馆

Conference on Biophotonics - Photonic Solution for Better Health Care

作者： Tanev, Stoyan Pond, James Paddon, Paul Tuchin, Valery V. Carleton Univ Dept Syst & Comp Engn 1125 Colonel By Dr Ottawa ON K1S 5B6 Canada Lumer Solut Inc Vancouver BC Canada Saratov NG Chernyshevskii State Univ Inst Opt & Biophoton Saratov 410012 Russia Inst Precise Mech Control RAS Saratov 410028 Russia

ISBN: (纸本)9780819471895

The finite-difference time-domain (FDTD) approach is applied to model optical phase contrast microscope (OPCM) imaging of Gold nanoparticles (NPs) in singe biological cells. We first demonstrate the effect of optical clearing on the optical phase contrast microscope image of a realistic size biological cell containing a cytoplasm, a nucleus and a membrane. The FDTD-based OPCM model is then applied to visualize the presence of a cluster of Gold NPs in the cytoplasm at optical conditions. To the best of our knowledge. this is the first study using the FDTD approach in combination with Fourier optics techniques to construct OPCM images of realistic size cells containing NPs. The results demonstrate the potential of the FDTD modelling approach and extend its area of applicability into a new biomedical research area.

关键词： biological cell finite-difference time-domain method optical phase contrast microscopes optical clearing effect gold nanoparticle

来源：评论

学校读者我要写书评

暂无评论

Imaging of photonic crystal slabs with non-ideal effective refractive index

Imaging of photonic crystal slabs with non-ideal effective r...

引用

International Conference on Application of Photonics Technology (Photonics North 2008)

作者： Sun, Guilin Kirk, Andrew G. McGill Univ Dept Elect & Comp Engn Montreal PQ H3A 2A7 Canada

ISBN: (纸本)9780819473288

finite-sized photonic crystal slabs have an effective refractive index that differs from that calculated for infinite structures. We investigate the imaging characteristics of such slabs with non-ideal effective refractive index n(eff), namely |n(eff)| <1 and |n(eff)| >1 at the 2(nd) band of hexagonal lattice, and observe an approximately linear object-image relation and saturated imaging. We focus on the slab aperture effect on imaging and analyze the mechanisms of image formation. For the finite-sized photonic crystal slab with fixed object distance, due to beam leakage, there is a limiting aperture size beyond which the image resolution and image distance remain almost unchanged. A larger aperture does not necessarily lead to higher image resolution. In order to be focused by the slab with negative refraction, the physical source or the object must contain sufficient transversal wavevectors or higher transversal spatial frequencies. The analyses are for the cases where propagating waves dominate imaging formation.

关键词： photonic crystal slab imaging negative refraction effective refractive index object-image relation finite-difference time-domain method

来源：评论

学校读者我要写书评

暂无评论

FDTD analysis of 2-D unmagnetized plasma photonic crystals

FDTD analysis of 2-D unmagnetized plasma photonic crystals

引用

International Conference on Microwave and Millimeter Wave Technology

作者： Lu Lu Liu Shaobin Nanjing Univ Aeronaut & Astronaut Nanjing 210016 Peoples R China

ISBN: (纸本)9781424418794

The plasma photonic crystal (PPC) is a periodic array composed of alternating thin unmagnetized (or magnetized) plasmas and dielectric materials (or vacuum). In this paper, the piecewise linear current density recursive convolution (PLCDRC) finite-difference time-domain (FDTD) method for the simulation of unmagnetized 2-D cylindrical plasma is applied to model unmagnetized PPCs structures. A perfectly matched layer (PML) absorbing material is used in these simulations. In frequency-domain, the reflection and transmission coefficients through unmagnetized PPCs are computed and their dependence on plasma frequency, background permittivity, collision frequency is studied. The results show theoretically that the photonic band gaps of unmagnetized PPCs be tuned by the plasma parameters.

关键词： dielectric materials finite difference time-domain analysis photonic crystals 2D unmagnetized plasma photonic crystals FDTD analysis finite-difference time-domain method perfectly matched layer absorbing material periodic array piece

来源：评论

学校读者我要写书评

暂无评论

High-order accurate FDTD method based on the combination of staggered backward differentiation integrator with optimal central finite difference scheme

引用

MICROWAVE AND OPTICAL TECHNOLOGY LETTERS 2007年第8期49卷 1802-1804页

作者： Xiao, Fei Tang, Xiaohong Univ Elect Sci & Technol China Sch Elect Engn Chengdu Peoples R China

In this letter, a high order accurate FDTD method is proposed, in which a fourth-order accurate staggered backward differentiation integrator is used for time marching and a new finite difference scheme named the optimal central finite difference scheme is used for spatial discretization. The analysis shows that the numerical dispersion of the new method can be reduced to some extent in comparison with that of the former fourth-order accurate FDTD method while no extra computation cost is involved. (c) 2007 Wiley Periodicals, Inc.

关键词： finite-difference time-domain method optimal central finite difference scheme staggered backward differentiation integrator

来源：评论

学校读者我要写书评

暂无评论

Ray-tracing technique and imaging properties by a PC slab with neff=-1

Ray-tracing technique and imaging properties by a PC slab wi...

引用

2008 International Conference on Optical Instruments and Technology

作者： Y.Wang~(*a,b) Jiabi Chen~a W.Qian~a a College of Optical and Electronic Information Engineering,Shanghai University of Science and Technology Shanghai 200093,China b College of physics and communication electronics,Jiangxi Normal University Nanchang 330022,China

In recent years,negative refractive media as the representation of new electromagnetic medium has become the front and the very popular researching field,and the production of the flat lens is one of its major *** our study,the imaging behaviors by two-dimensional photonic crystal slabs have been investigated *** suggest a ray-tracing technique to discuss the action of photonic crystal slab with negative *** propagation of electromagnetic waves in two-dimensional hexagonal lattice photonic crystal slab is investigated through dispersion characteristics analysis and numerical simulation of field *** and focusing with effective negative refractive index of-1 have been observed in these systems for both polarized waves,that is TE- and TM-polarized point source be considered *** on the exact finite-difference time-domain method to perform numerical simulation and physical analysis,we have demonstrated that the two-dimensional photonic crystal we designed can realize nearly perfect imaging with TM-polarized point source in the near field and far field,and the results are consistent with the ray-tracing technique quite well,while to TE-polarized point source the imaging is not perfect although it have neff=-l in the same direction.

关键词： negative refraction photonic crystal finite-difference time-domain method

来源：评论

学校读者我要写书评

暂无评论

The effect of the 2-D Laplacian operator approximation on the performance of finite-difference time-domain schemes for Maxwell's equations

引用

JOURNAL OF COMPUTATIONAL PHYSICS 2007年第1期227卷 513-536页

作者： Panaretos, Anastasios H. Aberle, James T. Diaz, Rodolfo E. Arizona State Univ Dept Elect Engn Tempe AZ 85287 USA

The behavior of the finite-difference time-domain method (FDTD) is investigated with respect to the approximation of the two-dimensional Laplacian, associated with the curl-curl operator. Our analysis begins from the observation that in a two-dimensional space the Yee algorithm approximates the Laplacian operator via a strongly anisotropic 5-point approximation. It is demonstrated that with the aid of a transversely extended-curl operator any 9-point Laplacian can be mapped into FDTD update equations. Our analysis shows that the mapping of an isotropic Laplacian approximation results in an isotropic and less dispersive FDTD scheme. The properties of the extended curl are further explored and it is proved that a unity Courant number can be achieved without the resulting scheme suffering from grid decoupling. Additionally, the case, of a 25-point isotropic Laplacian is examined and it is shown that the corresponding scheme is fourth order accurate in space and exhibits isotropy up to sixth order. Representative numerical simulations are performed that validate the theoretically derived results. (c) 2007 Elsevier Inc. All rights reserved.

关键词： finite-difference time-domain method laplacian operator curl operator electromagnetics

来源：评论

学校读者我要写书评

暂无评论

Optical characterization of iridescent wings of Morpho butterflies using a high accuracy nonstandard finite-difference time-domain algorithm

引用

OPTICAL REVIEW 2007年第6期14卷 359-361页

作者： Banerjee, Saswatee Dong, Zhu Sumitomo Chem Co Ltd Tsukuba Ibaraki 3003294 Japan Univ Tsukuba Grad Sch Syst & Informat Engn Tsukuba Ibaraki 3058577 Japan

In certain species of moths and butterflies iridescent colors arise from subwavelength diffractive surface corrugation of the wing-scales. The optical properties of such structures depend strongly on wavelength, incidence angle, and state of polarization of illuminating radiation, and the viewing angle. In this paper, we study the reflection spectra of the wings of the Morpho didius butterfly by simulating a double-layered model of a transverse cross-section comprised of the ground scale and the cover scale. Each layer contains a certain quasi-periodic arrangement of tree-like subwavelength micro structures. The simulation is done using a high accuracy nonstandard finite-difference time-domain (FDTD) method in two dimensions. We assume that the structure is made of a slightly lossy dielectric material. The wavelength dependence of the complex refractive index for the ground scale of Morpho didius is assumed to be similar to that of Morpho sulkowskyi. The complex refractive index in the latter case was obtained by comparing the computed reflection/transmission spectra with corresponding experimental measurements at normal incidence. (C) 2007 The Optical Society of Japan.

关键词： Morpho butterflies butterfly iridescence structural color subwavelength diffractive optical elements gratings and diffraction interference electromagnetic theory finite-difference time-domain method

来源：评论

学校读者我要写书评

暂无评论

Near-field optics imaging in silica waveguide using near-field scanning optical microscope

引用

JAPANESE JOURNAL OF APPLIED PHYSICS PART 1-REGULAR PAPERS BRIEF COMMUNICATIONS & REVIEW PAPERS 2007年第1期46卷 238-242页

作者： Chau, Yuan-Fong Tsai, Din Ping Ching Yun Univ Dept Elect Engn Jungli Taiwan Natl Taiwan Univ Dept Phys Taipei 10764 Taiwan Natl Taiwan Univ Ctr Nanostrage Res Taipei 10764 Taiwan

We investigated the near-field optics imaging by a numerical method using special spherical chains created in a silica waveguide (SWG) and explored the possibility of how this can be used for near-field scanning optical microscopy (NSOM) applications. There are two types of spherical nanochain;type A includes nano-dielectric spheres connected closely, and type B includes silver nanoparticles 4 nm in diameter randomly distributed inside the nanospheres of type A. A spherical nanochain with the 80-nm-diameter spheres was embedded in the SWG. The interactions between light emerging from SWG and the electric field near the sample surface that affects the properties of the images produced by NSOM are analyzed using a three dimensional finite-difference time-domain method. The effects of the optical field distribution generated by some factors are also discussed. A method of controlling the light field localized in the SWG is proposed that uses the external protrusion (dielectric sphere). The proposed structure will yield some useful information and give an idea of applications in NSOM.

关键词： silica waveguide super-RENS finite-difference time-domain method scanning optical microscopy (NSOM) nanoparticles

来源：评论

学校读者我要写书评

暂无评论

An upwinding boundary condition capturing method for Maxwell's equations in media with material interfaces

引用

JOURNAL OF COMPUTATIONAL PHYSICS 2007年第1期225卷 342-362页

作者： Xue, Changfeng Deng, Shaozhong Univ N Carolina Dept Math & Stat Charlotte NC 28223 USA Yancheng Inst Technol Dept Fundamental Sci Yancheng 224003 Jiangsu Peoples R China Peking Univ State Key Lab Turbulence & Complex Syst Beijing 100871 Peoples R China

By using ghost points on either side of the interfaces, a global second-order accurate upwinding boundary condition capturing method for time-domain Maxwell's equations in media with material interfaces is proposed. The equations are discretized on a uniform Cartesian grid and the interfaces are allowed to intersect the grid in an arbitrary fashion. The method is then obtained by combining central finite difference schemes with applicable nodes being replaced by the ghost points and upwinding technique with jump conditions across the interfaces being captured in a manner that the upwind property is always satisfied. The resulting discretization has the desirable property that the allowed time step size is independent of the locations and the shapes of the interfaces. Numerical examples are then given to demonstrate the second-order accuracy as well as the stability of the method, where it is used to study wave equations with various types of material interfaces, including electromagnetic scattering of a plane incident wave by a dielectric circular cylinder. (c) 2006 Elsevier Inc. All rights reserved.

关键词： finite-difference time-domain method ghost fluid method Maxwell's equations

来源：评论

学校读者我要写书评

暂无评论

Efficient FDTD method for analysis of mushroom-structure based left-handed materials

引用

IET MICROWAVES ANTENNAS & PROPAGATION 2007年第1期1卷 100-107页

作者： Wu, W.-Y. Lai, A. Kuo, C. -W. Leong, K. M. K. H. Itoh, T. Natl Sun Yat Sen Univ Dept Elect Engn Kaohsiung 804 Taiwan Univ Calif Los Angeles Dept Elect Engn Los Angeles CA 90095 USA

A finite-difference time-domain method, combined with thin-wire and thin-slot algorithms, which is used to analyse a metamaterial based on periodic mushroom structures, is proposed. This proposed method is suitable for analysing problems involving large structures with fine structural details. Several composite right/left handed (CRLH) metamaterial mushroom-based structures are investigated. A 19 x 8 flat lens and a parabolic lens structure composed of 410 unit mushroom cells are investigated and they demonstrate negative-refractive-index characteristics while operating in the LH region. The simulation and measurement results of one- and two-dimensional CRLH mushroom-based structures are compared. The periodic analysis for mushroom structures is also introduced. Only a single unit mushroom cell is required to present the phenomena of infinite periodicity with periodic boundary conditions.

关键词： Microwave materials metamaterials thin-wire algorithms flat lens Other numerical methods periodic analysis periodic structures periodic mushroom structures metarnaterial FDTD method fine structural details finite difference time-domain analysis periodic boundary conditions large structures thin-slot algorithms mushroomstructure based left-handed materials negative-refractive-index characteristics infinite periodicity composite right/left handed structures finite-difference time-domain method parabolic lens

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：