The Experts below are selected from a list of 273 Experts worldwide ranked by ideXlab platform

W.h. Ip - One of the best experts on this subject based on the ideXlab platform.

  • A hybrid artificial intelligence system for optical Lens Design
    International Journal of Computer Applications in Technology, 2020
    Co-Authors: C K Kwong, W.h. Ip
    Abstract:

    The current approach to optical Lens Design still relies very much on the Lens Designers: experience and knowledge. In the initial Lens Design, it is normally performed by Lens Designers and then is optimised by using some optimisation techniques. This research aims to Design and develop a computer-aided optical Lens Design system for automating the entire Design process. In this paper, various approaches to optical Lens Design are briefly reviewed first. It is then followed by the descriptions of a hybrid artificial intelligence (AI) approach, based on the case based reasoning and genetic algorithm, to optical Lens Design. A prototype optical Lens Design system based on the hybrid approach was proposed and developed. The system not only could generate an initial and optimal optical Lens Design automatically but also demonstrate that the Design could be done in lean knowledge paradigm.Department of Industrial and Systems Engineerin

  • Hybrid artificial intelligence system for optical Lens Design
    International Journal of Computer Applications in Technology, 2000
    Co-Authors: S M Tam, C K Kwong, W.h. Ip
    Abstract:

    The current approach to optical Lens Design still relies very much on the Lens Designers' experience and knowledge. In the initial Lens Design, it is normally performed by Lens Designers and then is optimized by using some optimization techniques. This research aims to Design and develop a computer-aided optical Lens Design system for automating the entire Design process. In this paper, various approaches to optical Lens Design are briefly reviewed first. It is then followed by the descriptions of a hybrid artificial intelligence (AI) approach, based on the case based reasoning and genetic algorithm, to optical Lens Design. A prototype optical Lens Design system based on the hybrid approach was proposed and developed. The system not only could generate an initial and optimal optical Lens Design automatically but also demonstrate that the Design could be done in lean knowledge paradigm.

Ellis I. Betensky - One of the best experts on this subject based on the ideXlab platform.

  • fundamental considerations for zoom Lens Design
    Proceedings of SPIE, 2012
    Co-Authors: Richard N. Youngworth, Ellis I. Betensky
    Abstract:

    Zoom Lens Design requires a very strong understanding of geometrical optics and how it directly relates to an optical system. Understanding both first-order optics and pupil conjugation is absolutely essential to ensure that a Lens zooms correctly and avoids discontinuities. This tutorial paper explains these first-order considerations in detail and illustrates how to derive a starting configuration. The tutorial also shows how to proceed toward a final Lens optimization.

  • Lens Design with Forbes aspheres
    Optical Design and Engineering III, 2008
    Co-Authors: Richard N. Youngworth, Ellis I. Betensky
    Abstract:

    Lens Design is a continually expanding field being driven by applications with increasingly difficult packaging and imaging constraints. In order to meet the challenges posed by current and future Design tasks, axisymmetric aspheric optical surfaces deviating from conicoids are required. Practical use of such surfaces is being enabled by ever-improving manufacturing and metrology methods. In this paper Lens Design with Forbes' orthogonal aspheres is investigated. The significant advantages of such an orthogonal representation for Design of systems with good performance and manufacturability are highlighted.

  • Forty years of modern zoom Lens Design
    Proceedings of SPIE, 2005
    Co-Authors: Ellis I. Betensky
    Abstract:

    Brought on by the availability of large computers and optimizations programs, zoom Lens Design has advanced continuously during the past forty years. Changes in applications, manufacturing, and requirements have all contributed to a large and growing knowledge of zoom Lens Design. As a result entirely new zoom Lens forms have been developed for use in a variety of cameraas and instruments. Most of the new Designs are characterized by complex motions of zooming groups, and particularly by moving the aperture stop during zooming. Continuing to find ways to control the internal pupil imaging, the compound zoom Lens has been developed. By performing the zooming operation on both sides of an intermediate image, the pupils and images are located advantageously.

  • Postmodern Lens Design
    Optical Engineering, 1993
    Co-Authors: Ellis I. Betensky
    Abstract:

    Global optimization is examined from the viewpoint of Lens Design for commercial production optics and is found to be unsatisfactory in its present state because of the need of the Lens Designer to remain involved in rather than divorced from the work. A genetic algorithm based on the use of nearly zero power operators that perform structural changes to a Gaussian optics system Design is proposed. The algorithm selects operators that improve system performance or fitness using procedures of mating and random crossover and breeds succeeding generations of new operators that, when applied to the starting Gaussian optics system and then optimized, yield an improved Lens Design. The algorithm is efficient, robust, and allows Lens Designers to relate to Designs in terms of aberration correcting means.

Robert R. Shannon - One of the best experts on this subject based on the ideXlab platform.

  • Lens Design DOING MORE WITH LESS
    Optics & Photonics News, 1994
    Co-Authors: Robert R. Shannon
    Abstract:

    Some might think that writing an article about Lens Design would result in the generation of an historical document. Not true; activity in the field is greater than ever, and the field is accessible to a wider audience than ever before. The traditional view of Lens Design as a subject carried out by a few unusual individuals has changed. Anyone with interest and a few bucks can get access to the latest and greatest software, on their own personal computer.

  • Teaching Lens Design
    Optical Engineering, 1993
    Co-Authors: Robert R. Shannon
    Abstract:

    Lens Design is one of the most basic activities in optical engineering. The subject requires an active working knowledge of all aspects of optics, and is a profession changing with the rise of new techniques in modern optics. The approach to teaching the subject is discussed, and the changes that have taken place over the past few decades are described.

  • Teaching of Lens Design
    Education in Optics, 1992
    Co-Authors: Robert R. Shannon
    Abstract:

    Lens Design is both the art and the science involved in the application of basic optical principles to the creation of a set of parameters describing a Lens for an optical instrument employing refracting or reflecting components. The techniques involved in Lens Design incorporate the setup of a system using basic optical principles, the iteration of that initial description using geometrical optical principles and the analysis of the system in terms of its ability to convey information or energy to a detector.

Hikmet Kocabaş - One of the best experts on this subject based on the ideXlab platform.

  • A correlation of thin Lens approximation to thick Lens Design by using context based method in optics education
    12th Education and Training in Optics and Photonics Conference, 2014
    Co-Authors: Ömer Faruk Farsakoğlu, Ipek Atik, Hikmet Kocabaş
    Abstract:

    The effect of Coddington factors on aberration functions has been analysed using thin Lens approximation with optical glass parameters. The dependence of spherical aberration on Coddington shape factor for the various optical glasses in real Lens Design was discussed using exact ray tracing for the optics education and training purposes. Thin Lens approximation and thick Lens Design are generally taught with only lecturing method. But, thick Lens Design is closely related to the real life. Hence, it is more appropriate to teach thin Lens approximation and thick Lens Design with real-life context based approach. Context based teaching can be effective in solving problems in which the subject is very difficult and irrelevant. It also provides extensive evidence for optics education that students are generally unable to correctly apply the concepts of Lens Design to optical instruments currently used. Therefore, the outline of real-life context based thick Lens Design lessons were proposed and explained in detail considering thin Lens approximation.

  • A Correlation of Thin Lens Approximation to Thick Lens Design by Using Coddington Factors in Lens Design and Manufacturing
    Turkish journal of physics, 2001
    Co-Authors: Ömer Faruk Farsakoğlu, D. Mehmet Zengin, Hikmet Kocabaş
    Abstract:

    The effect of Coddington factors on aberration functions has been analysed using thin Lens approximation. Minimizing spherical aberrations of singlet Lenses using Coddington factors in Lens Design depending on Lens manufacturing is discussed. Notation of Lens test plate pairs used in Lens manufacturing is also presented in terms of Coddington shape factors. Introduction Aberrations are an inherent part of the optical system in Designing spherical Lenses. Minimization of aberrations is one of the most important concepts in Lens Design. Thin Lens approximation can be applied to build a model for thick Lens Design. Minimization of aberrations can be realised by considering the real conditions in Lens Design as a part of computer integrated Lens manufacturing [1]. When Lens Design is suitable for manufacturing conditions, it may have a wide range of usage; and when Lens Design fits manufacturing conditions as a result of the adaptation of already Designed Lenses in an optical system, the optical system complies with manufacturing conditions. Thus, Lens Design should be performed taking production conditions into consideration. Therefore, computations must be optimized in accordance with the constraints of available technology [2], [3]. The 271 FARSAKOĞLU, ZENGIN, KOCABAŞ constraints may be defined as Lens test plates, Lens materials and their properties, and manufacturing conditions. Consider the case of an optical device containing a number of Lenses Designed with their aberrations minimized. If the computed radii and parameters of Lenses do not fit the radii of the Lens test plates and parameters of materials available, any subsequent modifications will necessitate recontrol of the optical system and may lead to inconvenient situations. Coddington factors which appear in aberration functions in thin Lens approximation contribute to the improvement of Lens Design. When these contributions are kept in a specified order, the practical uses for Lens Design are obtained. In this study, the application basis on the usage of Coddington factors in Lens Design is discussed. The effectiveness of Coddington factors is examined by using optical glass parameters with thin Lens approximation. The dependence of spherical aberration on Coddington shape factor for thick Lenses is discussed using exact ray tracing. Its variations are examined in the visible and infrared region. As a result of conducted studies and experiences obtained in Lens production, spherical aberration variations of singlet Lenses depending on Coddington shape factor are analyzed with suitable examples. In addition, a notation is introduced on the usage of Lens test plate pairs used in Lens manufacturing. The usage of the introduced notation for Lens Design can be adapted to the relevant manufacturing conditions. This study is a typical route in this area and it satisfies Lens manufacturing requirements. Similar options within different ways are available in optical Design programs using test plate libraries. This present route, instead, is a correlation using Coddington factors in Lens Design and manufacturing. Furthermore, this correlation can even be applied in the same way to doublet Lenses under more specific conditions. 2. Thin Lens approximation Aberration minimization is the most significant yet inseparable part of Lens Design. Corresponding wave aberrations to transverse ray aberrations are unfavourable conditions for Lenses performance. Monochromatic aberrations in general, primary (fourth order) wave or third order ray aberrations can be minimized according to desired purposes. When a single Lens is considered, commonly only spherical aberration computations are performed in Lens Design. The minimization of other aberrations is taken into account in the optical system. Principally, it is very useful to evaluate aberrations and their parameters for thin Lenses in the first step. The primary wave aberration function for a thin Lens which has positive focal length is given by [4-7] : W (r, θ; η) = Csr + Ccηr cos θ + Caηr cos θ +Cdηr, (1) where the exit pupil is at the Lens; r and θ are the polar coordinates at the exit pupil; and η is the image height at the Gaussian image plane. The coefficients Cs, Cc, Ca, and Cd represent the coefficients of spherical aberration, coma, astigmatism, and field curvature respectively. These coefficients in Eq. (1) may be given as follows: 272 FARSAKOĞLU, ZENGIN, KOCABAŞ CS = −[32n(n− 1)f3]−1 [ n+ 2 n− 1 2 + (3n+ 2)P 2 + 4(n+ 1)SP + n n− 1 ] ; (2a) CC = [4nif2]−1 [ n+ 1 n− 1 + (2n+ 1)P ] ; (2b) Ca = −[2if ]−1; (2c) Cd = −(n + 1)[4nif ]−1, (2d) where n is the refractive index of the optical glass, f is the paraxial focal length, and i is the image distance. The coefficient of distortion or wave front tilt is non-existent taking into account the exit pupil at the Lens [6]. In terms of the coefficient Cs and Cc given by Eqs. (2a) and (2b), S and P are called Coddington Shape Factor (CSF) and Coddington Position Factor (CPF), respectively. Coddington Shape Factor S determines the amount of curving as a function of the radii, R1 and R2, and is given by S = R2 + R1 R2 − R1 . (3) Each value of S describes the physical shape of the Lens so that contributions of Lens surfaces for refractions are determined in accordance with Lenses having negative or positive focal lengths. Coddington position factor P is given by P = i + o i− o , (4) where i is the image distance and o is the object distance. Each value of P indicates the location of the usage of the Lens in the optical system. As seen in Eqs. (2a) and (2b) the spherical aberration and coma of the Lens depend on CSFs and CPFs. On the other hand, the coefficients of astigmatism and field curvature which are represented by Eqs. (2c) and (2d) do not depend on CSFs and CPFs for the exit pupil at the Lens. Therefore, these coefficients were not considered in this study. Differentiation with respect to S of Eq. (2a) equals zero end thus gives the minimum spherical aberration corresponding to Smin and the relationship between Smin and Coddington position factor P . The above formulation can be applied to optical glasses and other Lens materials, as well as expanded and applied to thick Lenses. In the visible range, the calculation of refractive indices and Abbe values of optical glasses is commonly performed at wavelength 587.5618 nm (the yellow helium line). In this case, the variations of Lens characteristics for the various optical glasses were obtained at this wavelength. By using Eq.(2a) and Smin the variations of minimum spherical aberrations with CSF values are given in Fig. 1. As shown in Fig. 1, the parabolic curves of variations shift downward in terms of enhancement of the refractive index of optical glasses. It indicates that in thin Lens approximation the best shape Lenses of flint type glasses have lower spherical aberration than the best shape Lenses of crown type glasses. However, zero spherical aberration for 273 FARSAKOĞLU, ZENGIN, KOCABAŞ the glasses with the Designations of 464658, 517642, 785258, and 952204 occurs at absolute CPF values of 4.85, 4.46, 3.31, and 2.92, respectively. Glass Designation has six digit numbers to describe optical specifications: the first three digits indicate the refractive index, and the second three digits represent the Abbe value. In addition, variations of spherical aberrations of Lenses having negative focal length form the symmetrical plane with respect to Smin axis of spherical aberration variations of Lenses have positive focal length. For minimizing spherical aberration, it is useful to do the computation at infinite conjugate ratio, P = -1. In this case the variations of spherical aberrations with CSF values for various optical glasses are given in Fig. 2. As shown in this figure, every parabola has a value of (Smin, Csmin) at its vertex for parallel incident light, that the parabolas vary symmetrically, and the parabola shape and vertex strongly depend on CSF and refractive index values. 0.5 0.4 0.3 0.2 0.1 0 -0.1 -0.2 -4 -3 -2 -1 0 1 2 3 4 Smin -C sm in f 3 464658 517642

Donald C. Dilworth - One of the best experts on this subject based on the ideXlab platform.

  • The Ascendency of Numerical Methods in Lens Design
    Journal of Imaging, 2018
    Co-Authors: Donald C. Dilworth
    Abstract:

    Advancement in physics often results from analyzing numerical data and then creating a theoretical model that can explain and predict those data. In the field of Lens Design, the reverse is true: longstanding theoretical understanding is being overtaken by more powerful numerical methods.

  • Man versus machine: a Lens Design challenge
    Proceedings of SPIE, 2013
    Co-Authors: Donald C. Dilworth, David Shafer
    Abstract:

    After a generation of writing and improving Lens Design software, it is time to assess where we are. Specifically, can a modern program compete with, or surpass, the best human Designers? Here we describe a friendly contest between two leaders in the field.

  • Invited paper: Expert systems in Lens Design
    1990 Intl Lens Design Conf, 1991
    Co-Authors: Donald C. Dilworth
    Abstract:

    The SYNOPSYS - expert-systems program XSYS - is a radical departure from traditional methods of Lens Design. I describe typical problems that were presented to XSYS and show how the program can find useful sometimes unexpected starting points. 1.