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conference on current developments in Lens design and optical engineering viII

作者： van Turnhout, Maarten Bociort, Florian Delft Univ Technol Opt Res Grp Lorentzweg 1 NL-2628 CJ Delft Netherlands

ISBN: (纸本)9780819468154

Local optimization algorithms, when they are optimized only for speed, have in certain situations an unpredictable behavior: starting points very close to each other lead after optimization to different minima. In these cases, the sets of points, which, when chosen as starting points for local optimization, lead to the same minimum (the so-called basins of attraction), have a fractal-like shape. Before it finally converges to a local minimum, optimization started in a fractal region first displays chaotic transients. The sensitivity to changes in the initial conditions that leads to fractal basin borders is caused by the discontinuous evolution path (i.e. the jumps) of local optimization algorithms such as the damped-least-squares method with insufficient damping. At the cost of some speed, the fractal character of the regions can be made to vanish, and the downward paths become more predictable. The borders of the basins depend on the implementation details of the local optimization algorithm, but the saddle points in the merit function landscape always remain on these borders.

关键词： optimization optical system design saddle points fractals basins of attraction

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Third-order aberration solution using aberration polynomials for a general zoom lens design

Third-order aberration solution using aberration polynomials...

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conference on current developments in Lens design and optical engineering viII

作者： An, Hyun Kyoung Rayces, Juan L. Reardon, Patrick J. Univ Alabama Ctr Appl Opt Huntsville AL 35899 USA JL Rayces Consulting Tucson AZ 85718 USA

ISBN: (纸本)9780819468154

A mathematical approach for the third order solution for a general zoom lens design is proposed. The design starts with a first-order layout. Lens elements with the proper refracting power are placed at the proper distances to meet the physical constraints of the intended lens system. For the third-order design stage, a matrix notation called "Aberration Polynomial," which clarifies the linearity of the transformation from a normal thin group configuration to a general thin,group configuration by pupil shift and conjugate shift theory is implemented. The purpose of the method is correcting low-order aberrations during the preliminary design of zoom lenses. The goal is to mathematically reduce to zero the four aberration coefficients of the third-order (spherical aberration, coma, astigmatism, and distortion) rather than searching for a minimum by commercial design software. Once this theory is proven and accepted, it becomes possible to determine how many groups are needed for a particular optical system. The method of aberration polynomials establishes the number of groups needed to correct a given number of aberrations at a Given number of zoom positions. Furthermore, it provides the shape or bending of the elements, from where it will be possible to continue to optimize with standard methods.

关键词： Zoom lenses Monochromatic aberrations Lens design Chemical elements Distortion Astatine Patents Geometrical optics Spherical lenses optical engineering

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vision multiplexing: an optical engineering concept for low-vision aids

Vision multiplexing: an optical engineering concept for low-...

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conference on current developments in Lens design and optical engineering viII

作者： Peli, Eli Harvard Univ Sch Med Dept Ophthalmol Schepens Eye Res Inst Boston MA 02115 USA

ISBN: (纸本)9780819468154

The normal visual system provides a wide field of view apparently at high resolution. The wide field is continuously monitored at low resolution for navigation and detection of objects of interest. These objects are sampled using the high-resolution fovea, applying a temporal multiplexing scheme. Most vision impairments that cause low vision impact upon only one of the components;the peripheral low-resolution wide field or the central high-resolution fovea. The loss of one of these components prevents the interplay of central and peripheral vision needed for normal function and causes disability. Traditional low-vision aids improve the impacted component, but usually at a cost of a significant loss in the surviving component. For example, magnifying devices increase resolution but reduce the field of view, while minifying devices increase the field of view but reduce resolution. A general optical engineering approach - vision multiplexing - is presented. vision multiplexing seeks to provide both the wide field of view and the high-resolution information in ways that could be accessed and interpreted by the visual system. The use of various optical and electro-optical methods in the development of a number of new visual aids, all of which apply vision multiplexing to restore the interplay of high-resolution and wide-angle vision using eye movements in a natural way, will be described. vision-multiplexing devices at various stages of development and testing illustrate the successes and difficulties in applying this approach for patients with tunnel vision, hemianopia (half blindness), and visual acuity loss (usually due to central retinal disease).

关键词： bioptic telescope in-the-lens telescope IOL macular degeneration peripheral prisms retinitis pigmentosa

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A design of real time image capturing and processing system using Texas instrument's processor

A design of real time image capturing and processing system ...

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Multimedia Systems and Applications X

作者： Wee, Toon-Joo Chaisorn, Lekha Rahardja, Susanto Gan, Woon-Seng Institute for Infocomm Research Singapore 119613 Singapore School of EEE Nanyang Technology University Singapore 639798 Singapore

ISBN: (纸本)9780819469373

In this work, we developed and implemented an image capturing and processing system that equipped with capability of capturing images from an input video in real time. The input video can be a video from a PC, video camcorder or DVD player. We developed two modes of operation in the system. In the first mode, an input image from the PC is processed on the processing board (development platform with a digital signal processor) and is displayed on the PC. In the second mode, current captured image from the video camcorder (or from DVD player) is processed on the board but is displayed on the LCD monitor. The major difference between our system and other existing conventional systems is that image-processing functions are performed on the board instead of the PC (so that the functions can be used for further developments on the board). The user can control the operations of the board through the Graphic User Interface (GUI) provided on the PC. In order to have a smooth image data transfer between the PC and the board, we employed Real Time Data Transfer (RTDX™) technology to create a link between them. For image processing functions, we developed three main groups of function: (1) Point Processing;(2) Filtering and;(3) 'Others'. Point Processing includes rotation, negation and mirroring. Filter category provides median, adaptive, smooth and sharpen filtering in the time domain. In 'Others' category, auto-contrast adjustment, edge detection, segmentation and sepia color are provided, these functions either add effect on the image or enhance the image. We have developed and implemented our system using C/C# programming language on TMS320DM642 (or DM642) board from Texas Instruments (TI). The system was showcased in College of engineering (CoE) exhibition 2006 at Nanyang Technological University (NTU) and have more than 40 users tried our system. It is demonstrated that our system is adequate for real time image capturing. Our system can be used or applied for application

关键词： Real time systems

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Balancing detector effects with aberrations in the design of wide-field grazing incidence x-ray telescopes

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optical engineering 2006年第6期45卷 063003-1-063003页

作者： Harvey, James E. Atanassova, Martina Krywonos, Andrey Univ Cent Florida CREOL Orlando FL 32826 USA

Most imaging systems today include a mosaic detector array in the focal plane. optical designers of astronomical telescopes typically produce a design that yields a superb on-axis aerial image in the focal plane, and detector effects are included only in the analysis of the final system performance. Aplanatic optical designs (corrected for spherical aberration and coma) are widely considered to be superior to nonaplanatic designs. However, there is little merit in an aplanatic design for wide-field applications because one needs to optimize some field-weighted-average measure of resolution over the desired operational field of view (OFOV). Furthermore, when used with a mosaic detector array in the focal plane, detector effects eliminate the advantage of the aplanatic design even at small field angles. For wide fields of view, the focal plane is frequently despaced to balance field curvature with defocus thus obtaining better overall performance. We will demonstrate that including detector effects in the optical design process results in a different optimal (nonaplanatic) design for each OFOV that is even superior to an optimally despaced aplanatic design. (c) 2006 Society of Photo-optical Instrumentation Engineers.

关键词： detector effects wide-field imaging systems grazing incidence x-ray telescopes

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Stabilization of the line of sight of a cryogenic optical system

Stabilization of the line of sight of a cryogenic optical sy...

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conference on current developments in Lens design and optical engineering viI

作者： Ren, Qifeng Shen, Mangzuo Tan, Shuliang Liao, Sheng Chinese Acad Sci Inst Opt & Elect 4-9 Renminnan Rd Chengdu 610041 Peoples R China

ISBN: (纸本)0819463671

Cryogenic optical systems are often mounted in vacuum cryostat. An interesting concern in the mechanical design is how to maintain the stability of the line of sight (LOS) of the cryogenic optical system when it is cooled down to very low temperature. To investigate this problem an experimental cryogenic optical system, its mounting structure, and a cryostat were designed and fabricated. After assembling them together, a test experiment for measuring the LOS drift was carried out. Finally, the test results will be presented in this paper.

关键词： cryogenic optical system line of sight optomechanical design optical test

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End-to-end compensation of digital-optical imaging systems

End-to-end compensation of digital-optical imaging systems

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conference on current developments in Lens design and optical engineering viI

作者： Robinson, M. Dirk Stork, David G. Ricoh Innovat 2882 Sand Hill RdSuite 115 Menlo Pk CA 94025 USA

ISBN: (纸本)0819463671

Reliable fabrication and assembly of high-quality electro-optical imaging systems is a critical challenge facing electro-optical imaging system manufacturers. optical compensation is one standard approach for minimizing the effects of errors introduced during the manufacture and construction of the optical subsystems. We describe how digital image processing should be considered as a form of compensation when evaluating a complete imaging system. We describe a novel method for digital-optical compensation which jointly adjusts both optical parameters and image processing parameters to maximize end-to-end imaging performance. We verify the superiority of this joint compensation strategy over the traditional sequential compensation through several example imaging systems.

关键词： digital imaging optical design image processing lens testing compensation

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Fundamental and specific steps in Shack-Hartmann wavefront sensor design

Fundamental and specific steps in Shack-Hartmann wavefront s...

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conference on current developments in Lens design and optical engineering viI

作者： Curatu, Costin Curatu, George Rolland, Jannick Univ Cent Florida CREOL FPCE Coll Opt & Photon Orlando FL 32816 USA

ISBN: (纸本)0819463671

Shack-Hartmann sensors are widely used to measure wavefront aberrations. We present the fundamental and specific engineering steps in the design of Shack-Hartmann wavefront sensors. Typical performance requirements such as sensor dynamic range, sensitivity and accuracy are defined and discussed. We investigate the trade-offs between these performance metrics and the factors affecting the trade-offs. A first order approach for selecting the optimal parameters of the sensor central piece, the lenslet array, is presented. We also propose a quick tolerance analysis method that can predict the wavefront measurement error due to misalignments, using only the ray-tracing software.

关键词： wavefront sensing Shack-Hartmann sensor tolerance analysis

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A hardware-based simulation platform for optical design and engineering

A hardware-based simulation platform for optical design and ...

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conference on current developments in Lens design and optical engineering viI

作者： Ortiz, Fernando E. Durbano, James P. Sharkawy, Ahmed S. Shi, Shouyuan Curt, Petersen F. EM Photon 51 E Main StSuite 203 Newark DE 19711 USA

ISBN: (纸本)0819463671

optical lenses and systems have historically been of interest to the design and simulation community due to their extensive use in a variety of applications, including telecommunications and imaging. To simulate these systems, it is often possible to take advantage of symmetry or apply physical approximations, such as ray tracing and/or beam propagation, in order to avoid a rigorous solution of Maxwell's equations. However, in cases where these techniques are not applicable, such as when feature sizes become comparable to the wavelength of interest, full-wave electromagnetic simulations are required. Unfortunately, the time constraints and simulation sizes associated with many designs render this analysis infeasible or impractical, a problem that is aggravated by iterative design flows. Hence, a numerical platform capable of handling such computationally intense problems is necessary. In this paper, we present a hardware-based, full-wave simulation platform and demonstrate the advantages of hardware acceleration for the simulation of optical applications. Specifically, we will present a diffractive optical element (DOE) lens simulation, comparing results with previously published analytic and experimental data. We then modify the basic lens arrangement to produce an optical beam splitter. Because such a device cannot be analytically described using symmetry, this example will demonstrate the unique advantages of powerful hardware solvers for the analysis of DOE applications. Finally, we discuss how hardware-based solvers are critical for iterative designs by means of a 1-to-3 beam splitter example. This simulation system represents a new era in optical engineering, enabling the design of next-generation devices today.

关键词： optics lens DOE splitter design hardware simulation FDTD FPGA acceleration

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Looking for order in the optical design landscape

Looking for order in the optical design landscape

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conference on current developments in Lens design and optical engineering viI

作者： Bociort, Florian van Turnhout, Maarten Delft Univ Technol Opt Res Grp Lorentzweg 1 NL-2628 CJ Delft Netherlands

ISBN: (纸本)0819463671

In present-day optical system design, it is tacitly assumed that local minima are points in the merit function landscape without relationships between them. We will show however that there is a certain degree of order in the design landscape and that this order is best observed when we change the dimensionality of the optimization problem and when we consider not only local minima, but saddle points as well. We have developed earlier a computational method for detecting saddle points numerically, and a method, then applicable only in a special case, for constructing saddle points by adding lenses to systems that are local minima. The saddle point construction method will be generalized here and we Will show how, by performing a succession of one-dimensional calculations, many local minima of a given global search can be systematically obtained from the set of local minima corresponding to systems with fewer lenses. As a simple example, the results of the Cooke triplet global search will be analyzed. In this case, the vast majority of the saddle points found by our saddle point detection software can in fact be obtained in a much simpler way by saddle point construction, starting from doublet local minima.

关键词： saddle point optimization optical system design lithography

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