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丛书名： ISTE

2013年

作者： Jean‐Louis Guyader

ISBN: (数字)9780470612453

ISBN: (纸本)9781905209279

Three aspects are developed in this book: modeling, a description of the phenomena and computation methods. A particular effort has been made to provide a clear understanding of the limits associated with each modeling approach. Examples of applications are used throughout the book to provide a better understanding of the material presented.

关键词： aspects book description phenomena computation methods particular approach limits clear effort presented examples material better applications throughout elastic continuous vibrations equations conditions motion

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High-resolution and wide field-of-view fourier ptychographic microscopy

High-resolution and wide field-of-view fourier ptychographic...

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Frontiers in Optics, FIO 2013

作者： Yang, Changhuei California Institute of Technology 1200 E California Blvd MC 136-93 Pasadena CA 91125 United States

ISBN: (纸本)9781557529879

I will report on a new computational method for microscopy, Fourier Ptychographic Microscopy. This method performs phase retrieval through illumination angle diversity and allows us to transform a standard microscope with a 0.08 NA objective into a high-performance gigapixel microscope with 0.8 micron resolution, field-of-view of 120 mm2 and a long depth-of-field of 0.3 mm. This method transform the general challenge of standard microscopy from one coupled to the physical limitations of the system's optics to one that is computationally solvable. The method can significantly simplify digital pathology procedures. © OSA 2013.

关键词： computation methods Illumination Microscopy Phase retrieval General (000.0000) General science (000.2700)

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Transmissive structured illumination reveals target depth and cast shadow details obscured by scattering media

Transmissive structured illumination reveals target depth an...

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computational Optical Sensing and Imaging, COSI 2013

作者： Kumar, Avinash Gill, Patrick R. Vogelsang, Thomas Stork, David G. Rambus Utbs 1050 Enterprise Way Suite 700 Sunnyvale CA 94089 United States Department of Electrical and Computer Engineering University of Illinois Urbana-Champaign IL 61801 United States

We describe novel methods of computing sharp shadows and depth estimates of objects immersed in highly scattering media using multi-scale structured transmissive illumination, such as modified Hadamard tiles. © O... 详细信息

ISBN: (纸本)9781557529756

关键词： computation methods Illumination Light intensity Photometry Scattering media Structured illumination microscopy computation methods (080.1753) Nonimaging optics (080.4298) Scattering (290.0290)

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First-principle calculation of solar cell efficiency under incoherent illumination

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OPTICS EXPRESS 2013年第13期21卷 A616-A630页

作者： Sarrazin, Michael Herman, Aline Deparis, Olivier Univ Namur Solid State Phys Lab Res Ctr Phys Matter & Radiat PMR B-5000 Namur Belgium

Because of the temporal incoherence of sunlight, solar cells efficiency should depend on the degree of coherence of the incident light. However, numerical computation methods, which are used to optimize these devices, fundamentally consider fully coherent light. Hereafter, we show that the incoherent efficiency of solar cells can be easily analytically calculated. The incoherent efficiency is simply derived from the coherent one thanks to a convolution product with a function characterizing the incoherent light. Our approach is neither heuristic nor empiric but is deduced from first-principle, i.e. Maxwell's equations. Usually, in order to reproduce the incoherent behavior, statistical methods requiring a high number of numerical simulations are used. With our method, such approaches are not required. Our results are compared with those from previous works and good agreement is found. (C) 2013 Optical Society of America

关键词： Absorption spectroscopy computation methods Numerical simulation Power spectral density Solar cell efficiency Solar cells

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Comparison of numerical methods in near-field computation for metallic nanoparticles

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OPTICS EXPRESS 2011年第9期19卷 8939-8953页

作者： Karamehmedovic, Mirza Schuh, Roman Schmidt, Vladimir Wriedt, Thomas Matyssek, Christian Hergert, Wolfram Stalmashonak, Andrei Seifert, Gerhard Stranik, Ondrej Inst Werkstoffetech D-28359 Bremen Germany Univ Halle Wittenberg Inst Phys Theory Grp D-06120 Halle Germany Max Planck Inst Microstruct Phys D-06120 Halle Germany Inst Photon Technol Nanobiophoton Dept D-07702 Jena Germany

Four widely used electromagnetic field solvers are applied to the problem of scattering by a spherical or spheroidal silver nanoparticle in glass. The solvers are tested in a frequency range where the imaginary part of the scatterer refractive index is relatively large. The scattering efficiencies and near-field results obtained by the different methods are compared to each other, as well as to recent experiments on laser-induced shape transformation of silver nanoparticles in glass. (C) 2011 Optical Society of America

关键词： computation methods Field enhancement Finite difference time domain Material properties Mie theory Refractive index

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Radiation of a uniformly moving line charge in a zero-index metamaterial and other periodic media

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OPTICS EXPRESS 2012年第16期20卷 18515-18524页

作者： Yanai, Avner Levy, Uriel Hebrew Univ Jerusalem Dept Appl Phys Benin Sch Engn & Comp Sci IL-91904 Jerusalem Israel

Radiation of electromagnetic waves by a uniformly moving charge is the subject of extensive research over the last several decades. Fascinating effects such as Vavilov-Cherenkov radiation, transition radiation and the Smith-Purcell effect were discovered and studied in depth. In this paper we study the radiation of a line charge moving with relativistic constant velocity within an average zero index metamaterial consisting of periodically alternating layers with negative and positive refractive index. We observe a strong radiation enhancement, (similar to)3 orders of magnitude, for specific combinations of velocities and radiation frequencies. This surprising finding is attributed to a gigantic increase in the density of states at the positive/negative index boundary. Furthermore, we shed light on radiation effects of such a line charge propagating within the more "traditional" structure of periodically alternating layers consisting of positive and different refractive index with focus on frequencies satisfying the quarter wave stack and the half wave stack conditions. We show that the quarter-wave-stack case results in emission propagating vertically to the line charge trajectory, while the half-wave-stack results in negligible radiation. All these findings were obtained using a computationally efficient and conceptually intuitive computation method, based on eigenmode expansion of specific frequency components. For validation purposes this method was compared with the finite-difference-time-domain method. (C) 2012 Optical Society of America

关键词： computation methods Electromagnetic radiation Phase velocity Refractive index Rigorous coupled wave analysis Spatial frequency

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Application of the three-component bidirectional reflectance distribution function model to Monte Carlo calculation of spectral effective emissivities of nonisothermal blackbody cavities

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APPLIED OPTICS 2012年第33期51卷 8003-8012页

作者： Prokhorov, Alexander Prokhorova, Nina I. Virial Int LLC Gaithersburg MD 20878 USA

We applied the bidirectional reflectance distribution function (BRDF) model consisting of diffuse, quasi-specular, and glossy components to the Monte Carlo modeling of spectral effective emissivities for nonisothermal cavities. A method for extension of a monochromatic three-component (3C) BRDF model to a continuous spectral range is proposed. The initial data for this method are the BRDFs measured in the plane of incidence at a single wavelength and several incidence angles and directional-hemispherical reflectance measured at one incidence angle within a finite spectral range. We proposed the Monte Carlo algorithm for calculation of spectral effective emissivities for nonisothermal cavities whose internal surface is described by the wavelength-dependent 3C BRDF model. The results obtained for a cylindroconical nonisothermal cavity are discussed and compared with results obtained using the conventional specular-diffuse model. (C) 2012 Optical Society of America

关键词： Bidirectional reflectance distribution function computation methods Diffuse reflectance Fresnel reflection Optical properties Ray tracing

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Design of TIR optics generating the prescribed irradiance distribution in the circle region

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JOURNAL OF THE OPTICAL SOCIETY OF AMERICA A-OPTICS IMAGE SCIENCE AND VISION 2012年第9期29卷 1758-1763页

作者： Moiseev, Mikhail A. Doskolovich, Leonid L. Russian Acad Sci Image Proc Syst Inst Samara 443001 Russia Samara State Aerosp Univ Samara 443086 Russia LED Opt Design LLC Samara 443001 Russia

We present the method for computation of highly effective total internal reflection (TIR) optics for LED-based illumination systems. The computation problem is reduced to the integration of several explicit independent first-order differential equations. Two designs of TIR optics are considered and compared: with flat and with aspherical upper surface. The dependence of nonuniformity of generated irradiance distribution on the size of the light source is studied for both designs numerically. It is shown that point source approximation is acceptable in cases when the size of the light source is 5 (or more) times less than the distance to the inner surface of the optical element. (C) 2012 Optical Society of America

关键词： computation methods Illumination design Light sources Optical elements Optical surfaces Total internal reflection

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Study on transition from photonic-crystal laser to random laser

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OPTICS EXPRESS 2012年第7期20卷 7300-7315页

作者： Fujii, Garuda Matsumoto, Toshiro Takahashi, Toru Ueta, Tsuyoshi Nagoya Univ Dept Mech Sci & Engn Chikusa Ku Nagoya Aichi Japan Jikei Univ Sch Med Phys Lab Tokyo Japan

The dependence of the lasing threshold on the amount of positional disorder in photonic crystal structures is newly studied by means of the finite element method, not of the finite difference time domain method usually used. A two-dimensional model of a photonic crystal consisting of dielectric cylinders arranged on a triangular lattice within a circular region is considered. The cylinders are assumed to be homogeneous and infinitely long. Positional disorder of the cylinders is introduced to the photonic crystals. Optically active medium is introduced to the interspace among the cylinders. The population inversion density of the optically active medium is modeled by the negative imaginary part of dielectric constant. The ratio between radiative power of electromagnetic field without amplification and that with amplification is computed as a function of the frequency and the imaginary part of the dielectric constant, and the threshold of the imaginary part, namely population inversion density for laser action is obtained. These analyses are carried out for various amounts of disorder. The variation of the lasing threshold from photonic-crystal laser to random laser is revealed by systematic computations with numerical method of reliable accuracy for the first time. Moreover, a novel phenomenon, that the lasing threshold have a minimum against the amount of disorder, is found. In order to investigate the properties of the lasing states within the circular system, the distributions of the electric field amplitudes of the states are also calculated. (C) 2012 Optical Society of America

关键词： computation methods Finite difference time domain Laser modes Photonic crystal lasers Photonic crystals Random lasers

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Optical performance of symmetrical and asymmetrical Y-branch couplers for plastic optical fibers

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APPLIED OPTICS 2012年第19期51卷 4448-4456页

作者： Kuang, Jao-Hwa Chen, Pao-Chuan Chen, Yung-Chuan Natl Pingtung Univ Sci & Technol Dept Vehicle Engn Pingtung 91201 Taiwan Natl Sun Yat Sen Univ Dept Mech & Electromech Engn Kaohsiung 80424 Taiwan

The excess loss and output optical power ratio of symmetrical and asymmetrical Y-branch couplers for plastic optical fibers (POFs) are studied in this work. A ray-tracing model for the Y-branch coupler is derived to investigate the effect of coupling parameters on its optical performance. The coupling parameters, namely coupling angle, axial displacement, and refractive index of filling medium between the emitting-end and receiving-end POFs, are studied. The simulated and measured results indicate that the coupling efficiency is sensitive to all these coupling parameters. A minimum excess loss of approximately 0.83 dB is observed for the symmetrical Y-branch coupler. It is found that both the excess loss and the output power ratio are increased with the increase of the refractive index of the filling medium and the total coupling angle (alpha + beta) for the asymmetrical Y-branch coupler. The experimental results indicate that the maximum output power ratio P-1:P-2 is found to be 3.8:1 for excess loss of less than 2.8 dB for the asymmetrical Y-branch coupler. (C) 2012 Optical Society of America

关键词： Fiber optics and optical communications Buffers couplers routers switches and multiplexers Geometric optics computation methods

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