Structural design of a lens component with prespecified aberration targets by evolutionary algorithm
13 Sep 2007-Proceedings of SPIE (International Society for Optics and Photonics)-Vol. 6668, pp 254-265
TL;DR: The glass types for individual lens elements are treated as discrete independent variables to be selected from a set of prespecified list of actual glasses to reduce the chance of overlooking promising and better solutions by carrying out searches in the total configuration space simultaneously.
Abstract: In a recent paper we have reported on the feasibility of reducing the problem of structural design of a multicomponent
lens system in accordance with a prespecified set of Gaussian characteristics and primary aberration targets to the
relatively simpler problem of determining optimum structures for the component lenses with central aberration targets.
The structural design of the individual components can be suitably tackled by evolutionary algorithm so that one can
obtain globally or quasiglobally optimum solutions for the purpose. Details of the latter part of the approach are
presented in this paper.
Contrary to the usual practice of heuristic selection of glass types for the lens elements of the component, the glass types
for individual lens elements are treated as discrete independent variables to be selected from a set of prespecified list of
actual glasses. We have dealt with the global or quasiglobal synthesis of the individual lens components with the help of
structures of increasing complexity, e.g. singlets, cemented doublets, broken contact doublets, cemented triplets,
photovisual objectives etc. as necessary for the purpose. The total configuration space consists of continuous variables
like shape variable and power distributions, and discrete variables like available glass types. This approach reduces
significantly the chance of overlooking promising and better solutions by carrying out searches in the total configuration
space simultaneously. Some illustrative examples will be presented.
Citations
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TL;DR: Investigations on three-component zoom lens structures are reported, using evolutionary programming that explores the available configuration space formed by powers of the individual components, the intercomponent separations, and the relative movement parameters of the moving components.
Abstract: An approach for ab initio synthesis of the thin lens structure of linearly compensated zoom lenses is reported. This method uses evolutionary programming that explores the available configuration space formed by powers of the individual components, the intercomponent separations, and the relative movement parameters of the moving components. Useful thin lens structures of optically and linearly compensated zoom lens systems are obtained by suitable formulation of the merit function of optimization. This paper reports our investigations on three-component zoom lens structures. Illustrative numerical results are presented.
20 citations
TL;DR: The method has been successfully used to get thin lens structures of mechanically compensated, optically compensated, and linearly compensated zoom lens systems by suitable formulation of merit function of optimization.
Abstract: A new approach for 'ab initio' synthesis of thin lens structure of zoom lenses is reported. This is accomplished by an
implementation of evolutionary programming, based on Genetic Algorithm , which explores the available configuration
space formed by powers of individual components and inter-component separations. Normalization of the variables is
carried out to get an insight on the optimum structures. The method has been successfully used to get thin lens structures
of mechanically compensated, optically compensated, and linearly compensated zoom lens systems by suitable
formulation of merit function of optimization. Investigations have been carried out on three component and four
component zoom lens structures. Illustrative numerical results are presented.
19 citations
Additional excerpts
...49, 1111–1123 (2002) [22] S....
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TL;DR: A systematic approach for the aberration design of a four-component double-sided telecentric zoom lens system is presented and mean pupil spherical aberration of every component in every zoom position is adopted in the objective function to control high-order aberrations.
Abstract: A systematic approach for the aberration design of a four-component double-sided telecentric zoom lens system is presented. The Gaussian structure of the zoom system is specified previously which means the powers and movements of components are known. Each component is treated as a lens module during the design stage with specified first-order properties and third-order aberration targets. The third-order aberration targets of the first component are determined by minimizing the whole aberrations of the zoom lens system using a genetic algorithm (GA). And the aberration targets of components behind are determined by reoptimization with already fixed structures of previous components. Mean pupil spherical aberration of every component in every zoom position is adopted in the objective function to control high-order aberrations. The thin lens structure of each component can be determined from their first-order properties and aberration targets. After lens thickening and reoptimization, the zoom lens system can finally be determined.
12 citations
TL;DR: A new approach for structural synthesis of optically compensated zoom lenses by carrying out a global search over the available degrees of freedom, namely, powers of the components and the inter-component separations is reported.
Abstract: A new approach for structural synthesis of optically compensated zoom lenses is reported. An implementation of evolutionary programming facilitates the procedure by carrying out a global search over the available degrees of freedom, namely, powers of the components and the inter-component separations. Practical success of the method depends on suitable formulation of the fitness function. Normalization of the variables is carried out to get an insight on the optimum structures. Illustrative numerical results are presented.
9 citations
Cites background from "Structural design of a lens compone..."
...Use of genetic algorithms in structural design of fixed focus multi-component lens systems has been reported earlier ([16-18])....
[...]
TL;DR: The method has been successfully used to get thin lens structures of optically compensated zoom lens systems by suitable formulation of merit function of optimization by an implementation of evolutionary programming.
Abstract: A new approach for ‘ab initio’ synthesis of thin lens structure of optically compensated zoom lenses is reported. This is accomplished by an implementation of evolutionary programming that explores the available configuration space formed by powers of individual components and inter-component separations to obtain globally or quasiglobally optimum solutions for the problem. Normalization of the variables is carried out to get an insight on the optimum structures. The method has been successfully used to get thin lens structures of optically compensated zoom lens systems by suitable formulation of merit function of optimization. Investigations have been carried out on four-component zoom lens structures. Illustrative numerical results are presented.
8 citations
Cites methods from "Structural design of a lens compone..."
...Several aspects on implementation of this strategy have been reported earlier [2–7]....
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References
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TL;DR: The results of this feasibility study indicate that various types of aberrations can be corrected quickly and simultaneously, even on small computers.
Abstract: Natural evolution is widely accepted as being the process underlying the design and optimization of the sensory functions of biological organisms. Using a genetic algorithm, this process is extended to the automatic optimization and design of optical systems, e.g. as used in astronomical telescopes. The results of this feasibility study indicate that various types of aberrations can be corrected quickly and simultaneously, even on small computers.
43 citations
TL;DR: An alternative scheme is reported in this paper which aims at utilizing degrees of freedom in a more effective way at utilizing thin lens design of multicomponent systems with a prespecified set of primary aberration residuals and Gaussian characteristics.
Abstract: The thin lens design of multicomponent systems with a prespecified set of primary aberration residuals and Gaussian characteristics usually starts with the choice of a lens type followed by a selection of the glasses to be used for the elements of its different components. An alternative scheme is reported in this paper which aims at utilizing these degrees of freedom in a more effective way. The detailed structure of the individual components and the glasses to be used in the lens elements comprising them are determined after the feasibility of attaining the given aberration targets with viable components has been ascertained on a preliminary layout of components obtained from a consideration of Gaussian requirements and Petzval curvature of the desired system.
26 citations