检索结果-内蒙古大学图书馆

Calculation of diffraction characteristics of subwavelength conducting gratings using a high accuracy nonstandard finite-difference time-domain method

引用

OPTICAL REVIEW 2005年第4期12卷 274-280页

作者： Banerjee, S Cole, JB Yatagai, T Univ Tsukuba Inst Appl Phys Tsukuba Ibaraki 3058573 Japan Univ Tsukuba Dept Syst & Informat Engn Tsukuba Ibaraki 3058573 Japan

Gratings with subwavelength groove depth and period are frequently used in optics for various purposes. The polarization dependent diffraction characteristics of subwavelength (high frequency) gratings can only be calculated by solving Maxwell's equations of electromagnetism. In this paper, we calculate the classical diffraction characteristics of subwavelength conducting gratings numerically, using a new high accuracy version of nonstandard finite-difference time-domain (NS-FDTD) algorithm. For the purpose of analysis, we employ a gold sinusoidal grating with light incident at a large angle. We have compared high accuracy NS-FDTD simulation results with those obtained from standard finite-difference time-domain (S-FDTD), and the finite element method (FEM) simulations. (c) 2005 The Optical Society of Japan.

关键词： grating diffraction subwavelength diffractive optical elements conducting gratings microoptics electromagnetic theory finite-difference time-domain method

来源：评论

学校读者我要写书评

暂无评论

Rigorous electromagnetic analysis of Talbot effect with the finite-difference time-domain method

Rigorous electromagnetic analysis of Talbot effect with the ...

引用

Conference on Optical Design and Testing II

作者： Lu, YQ Zhou, CH Chinese Acad Sci Shanghai Inst Opt & Fine Mech Informat Opt Lab Shanghai 201800 Peoples R China

ISBN: (纸本)0819455938

We present the electromagnetic analysis of Talbot effect with the finite-difference time-domain (FDTD) method. To our knowledge, it is the first time that FDTD method is applied to analyze the performance of a Talbot illuminator. Furthermore, self-imaging performances of a grating with different flaws are analyzed. The FDTD method can be applied to analyze this kind of diffraction. Of course it also can be analyzed with the Fourier transform method. But for this non-period grating, it will be more complex. In addition, the grating employed here is a high-density grating. The Fourier transform method is not rigorous enough. For these reasons, the FDTD method can show the exact near-field distribution of different flaws in a high-density grating, which is impossible to attain with the conventional Fourier transform method.

关键词： Talbot array illuminators finite-difference time-domain method

来源：评论

学校读者我要写书评

暂无评论

Optimizing the spectral efficiency of photonic quantum well structures

引用

OPTIK 2009年第1期120卷 35-39页

作者： Liu, Jing Sun, Junqiang Huang, Chongqing Hu, Wenjing Huang, Dexiu Huazhong Univ Sci & Technol Wuhan Natl Lab Optoelect Wuhan 430074 Peoples R China Hunan Inst Sci & Technol Dept Phys Yueyang 414006 Hunan Peoples R China

One can construct photonic single quantum well structures by sandwiching a homogeneous medium slab as a defect between two symmetrical photonic crystals (PCs). It is shown that the number of observed resonant peaks increases with increasing slab thickness. It is found that while the slab is composed of alternatively stacked step-index films, the frequencies of these resonant peaks can be adjusted finely by changing the film thickness properly. In this case, the frequency and frequency interval of confined states can be tuned accurately, and the spectral efficiency can be greatly enhanced without increasing the volume of optical devices. Numerical simulation is based on the finite-difference time-domain (FDTD) method. (C) 2007 Elsevier GmbH. All rights reserved.

关键词： Spectral efficiency Confined states finite-difference time-domain method Photonic quantum well

来源：评论

学校读者我要写书评

暂无评论

METAMATERIAL SLABS AND REALIZATION OF ALL-TYPE FILTER CHARACTERISTICS: NUMERICAL AND ANALYTICAL INVESTIGATIONS

引用

MICROWAVE AND OPTICAL TECHNOLOGY LETTERS 2009年第4期51卷 894-899页

作者： Cimen, Sibel Cakir, Gonca Sevgi, Levent Kocaeli Univ Elect & Commun Engn Dept Kocaeli Turkey Dogucs Univ Elect & Commun Engn Dept Istanbul Turkey

Studies towords understanding and the use of metamaterials (MTM) have risen in electromagnetic engineering. This article presents analytical and numerical investigations of filter characteristics of MTMs in two-dimension (2D). Numerical investigations are. based oil finite difference little domain (FDTD) simulations, analytical formulations belong to a plane wave excitation of multi-slab structures. It is shown that a three layer structure with different combinations of MTMs and non-MTMs may be used to realize all four types of filter characteristics. (C) 2009 Wiley Periodicals. Inc. Microwave Opt Technol Lett 51: 894-899. 2009: Published online in Wiley InterScience (***). DOI 10.1002/mop.24196

关键词： metamaterial double negative double positive left handed multilayered slabs S-parameters finite-difference time-domain method FDTD microwave filters low pass filter band pass filter high pass filter band stop filter

来源：评论

学校读者我要写书评

暂无评论

A Study of Properties of the Photonic Band Gap of Unmagnetized Plasma Photonic Crystal

引用

Plasma Science and Technology 2009年第1期11卷 14-17页

作者：刘崧钟双英刘三秋 School of Sciences Nanchang University

In this study, the propagation of electromagnetic waves in one-dimensional plasma photonic crystals （PPCs）, namely, superlattice structures consisting alternately of a homogeneous unmagnetized plasma and dielectric material, is simulated numerically using the finite-difference time-domain （FDTD） algorithm. A perfectly matched layer （PML） absorbing technique is used in this simulation. The reflection and transmission coefficients of electromagnetic （EM） waves through PPCs are calculated. The characteristics of the photonic band gap （PBG） are discussed in terms of plasma density, dielectric constant ratios, number of periods, and introduced layer defect. These may provide some useful information for designing plasma photonic crystal devices.

关键词： plasma photonic crystal finite-difference time-domain method photonic band gap reflection and transmission coefficients

来源：评论

学校读者我要写书评

暂无评论

Investigation of a slot nanoantenna in optical frequency range

引用

PHOTONICS AND NANOSTRUCTURES-FUNDAMENTALS AND APPLICATIONS 2009年第3期7卷 161-168页

作者： Kumar, V. Dinesh Asakawa, Kiyoshi Natl Inst Mat Sci Tsukuba Ibaraki 3050047 Japan

Following the analogy of radio frequency slot antenna and its complementary dipole, we propose the implementation of a slot nanoantenna (SNA) in the optical frequency range. Using finite-difference time-domain (FDTD) method, we investigate the electromagnetic (EM) properties of a SNA formed in a thin gold film and compare the results with the properties of a gold dipole nanoantenna (DNA) of the same dimension as the slot. It is found that the response of the SNA is very similar to the DNA, like their counterparts in the radio frequency (RF) range. The SNA can enhance the near field intensity of incident field which strongly depends on its feedgap dimension. The resonance of the SNA is influenced by its slot length;for the increasing slot length, resonant frequency decreases whereas the sharpness of resonance increases. Besides, the resonance of the SNA is found sensitive to the thickness of metal film, when the latter is smaller than the skin depth. The effect of polarization of incident field on the EM response of the SNA was examined;the field enhancement is optimum when polarization is parallel to the feedgap. Finally, we calculate the radiation patterns of the DNA and SNA and compare them with those of the RF dipole antenna. The radiation pattern of the SNA is found to be independent of its slot length when excited at resonant frequency. To the best of our knowledge, this is the first study on a slot antenna in the optical frequency. (C) 2009 Elsevier B.V. All rights reserved.

关键词： Slot nanoantenna Dipole nanoantenna Radio frequency antenna finite-difference time-domain method Surface plasmon

来源：评论

学校读者我要写书评

暂无评论

FDTD Implementation and Application of High Order Impedance Boundary Condition Using Rational Functions

引用

IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION 2009年第8期57卷 2397-2408页

作者： Zheng, Hong-Xing Leung, Kwok Wa City Univ Hong Kong Dept Elect Engn Kowloon Hong Kong Peoples R China

An algorithm is proposed for the implementation of the high-order surface impedance boundary condition using the finite-difference time-domain method. The surface impedance function of a lossy medium is approximated by a series of rational functions in the Laplace domain, whereas the dyadic differential operator is approximated by a second-order power series. By assuming that the fields are piecewise linear, the time-domain convolution integrals are computed using a recursive formula. The impedance function of a coating layer is approximated by a third-order power series. The algorithm can be applied to scattering problems of a three-dimensional coating for both vertically and horizontally polarized waves. The advantage of the proposed method is that the result can be applied to media of arbitrary conductivities, with a wide range of incident angles from zero to graze. Some numerical examples are given to substantiate the theory.

关键词： Approximate operator expansion coating finite-difference time-domain method rational function scattering surface impedance boundary conditions

来源：评论

学校读者我要写书评

暂无评论

Evaluation of layer properties of effective parameters of metallic rod metamaterials in GHz frequencies

引用

AEU-INTERNATIONAL JOURNAL OF ELECTRONICS AND COMMUNICATIONS 2009年第8期63卷 648-652页

作者： Rybin, Oleg Raza, Muhammad Nawaz, Tahira Abbas, Tahir Bahauddin Zakariya Univ Ctr Adv Studies Pure & Appl Math Multan 60800 Pakistan Bahauddin Zakariya Univ Dept Phys Multan 60800 Pakistan

In this paper, analytical modeling and numerical simulation of the complex effective dielectric, magnetic constants and refractive index of a metallic rod metamaterial in microwave frequency range are presented. Analytical modeling has been done using modified mathematical models of the complex dielectric and magnetic constants obtained for rod metamaterial structure. Numerical simulation of the above-mentioned parameters has been made using S-parameters obtained with the help of finite-difference time-domain (FDTD) calculations. The numerical simulation has been carried out for different thickness of rods. Remarkable coincidence between analytical and numerical results was found. The effective dielectric constant enhancement of the considered composite has been obtained. Recommendations for the practical application of considered metamaterial structure for designing patch antennas have been discussed. (C) 2008 Elsevier GmbH. All rights reserved.

关键词： Metamaterials Effective medium theory Microwave finite-difference time-domain method Enhancement of the effective dielectric constant

来源：评论

学校读者我要写书评

暂无评论

Disorder effects in reflectance spectra of colloidal photonic crystals

引用

NUCLEAR INSTRUMENTS & methodS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS 2009年第2期267卷 393-396页

作者： Vinteler, E. Farcau, C. Astilean, S. Univ Babes Bolyai Fac Phys Cluj Napoca 400084 Romania Univ Babes Bolyai Inst Interdisciplinar Expt Res Nanobiophoton Lab Cluj Napoca 4000271 Romania

Although fabrication of photonic crystals improved over the last few years, intrinsic defects of the crystal lattice affect the experimentally measured spectral features. in order to compare experimental spectra with simulated photonic band structure, disorder effects are simulated by introduction of material absorption. By using the finite-difference time-domain (FDTD) method we were able in the past to obtain a good agreement between experimental and simulated transmission curves by taking in account the glass substrate. In this work we extend our analysis for reflectance curves of one, two and three-layered close-packed polystyrene spheres. We show that a key ingredient in simulating disorder effects is the introduction of fictional absorption for polystyrene. (c) 2008 Elsevier B.V. All rights reserved.

关键词： Colloidal photonic crystals finite-difference time-domain method

来源：评论

学校读者我要写书评

暂无评论

Commentary: Metallic nanodevices for chip-scale optical interconnects

引用

Journal of Nanophotonics 2009年第1期3卷

作者： Tang, Liang Miller, David A. B. Stanford University Ginzton Laboratory Stanford CA 94305 United States

No Abstract available.

关键词： Nanostructures Metals Antennas Sensors finite-difference time-domain method Germanium Near field optics Optical interconnects Electrons Semiconductors

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：