Aberration (optique)

Résumé

Une aberration est un défaut du système optique qui se répercute sur la qualité de l'image (flou, irisation ou déformation). Les aberrations sont définies par rapport à l'optique paraxiale et matérialisent le fait que certains rayons ne convergent pas vers l'image prédite par l'optique géométrique. Ainsi, la théorie des aberrations s'inscrit dans le cadre de l'optique géométrique et ne prend pas en compte les aspects ondulatoire ou corpusculaire de la lumière. Il est possible de classer les aberrations en deux groupes. D'une part, les aberrations chromatiques, dépendantes de la longueur d'onde, qui sont responsables d'erreurs d'ordre colorimétrique dans les images. D'autre part, les aberrations géométriques, dépendantes de paramètres géométriques (position de la pupille, ouverture numérique et angle de champ notamment) ont un impact sur le pouvoir de résolution du système. La conception optique permet de concevoir des systèmes peu aberrants en combinant des optiques dont les aberr

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https://fr.wikipedia.org/wiki/Aberration_(optique)

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Lens aberration compensation in interference microscopy

Yves Bellouard, Jakub Drs, Mingyu Liu

Emergence of products that feature functional surfaces with complex geometries, such as freeform optics in consumer electronics and augmented reality and virtual reality, requires high-accuracy non-contact surface measurement. However, large discrepancies are often observed between the measurement results of optical methods and contact stylus methods, especially for complex surfaces. For interference microscopy, such as coherence scanning interferometry, the three-dimensional surface transfer function provides information about the instrument spatial frequency passband and about lens aberrations that can result in measurement errors. Characterisation and phase inversion of the instrument's three-dimensional surface transfer function yields an inverse filter that can be applied directly to the three-dimensional fringe data. The inverse filtering is shown to reduce measurement errors without using any data processing or requiring any a priori knowledge of the surface. We present an experimental verification of the characterisation and correction process for measurements of several freeform surfaces and an additive manufactured surface. Corrected coherence scanning interferometry measurements agree with traceable contact stylus measurements to the order of 10 nm.

2020

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Full field dependence of primary aberrations in perturbed double-plane symmetric systems with a circular pupil

Alessandro Grosso, Toralf Scharf

This paper deals with the theory of primary aberrations for perturbed double-plane symmetric optical systems consisting of a combination of tilted and decentered surfaces and a circular pupil. First, the analytical expressions describing the full field behavior of Zernike polynomials are derived from the fourth-order wavefront aberration function for this class of optical systems. Then, such expressions are combined to retrieve the full field dependence of primary coma, primary astigmatism, and field curvature. They are described by an elliptical conic-shaped surface with a variable apex location over the field of view, by a binodal surface with two nodes over the field of view, and by a general elliptical surface with one node. The proposed analytical expressions provide a better understanding of the primary aberration behavior for these systems and can be of great use in their optical design and aberration correction. An optical system constituted by a pair of tilted and decentered biconic lenses is studied to validate the proposed expressions. (C) 2020 Optical Society of America

OPTICAL SOC AMER2020

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In this paper we derive scalar analytical expressions describing the full field dependence of Zernike polynomials in optical systems without symmetries. We consider the general case of optical systems constituted by arbitrarily tilted and decentered circular symmetric surfaces. The resulting analytical formulae are inferred from a modified version of the full field dependent wavefront aberration function proposed in the Nodal Aberration Theory (NAT). Such formula is modified with the scope of solving few critical points arising when primary and higher order aberrations are both present in an optical system. It is shown that when secondary aberrations are taken into account in the wavefront aberration function, the final effect is a perturbation to the symmetry of the field dependence of the Zernike polynomials. In particular, the centers of symmetry of the Zernike polynomial field dependences are shifted with respect to the locations predicted using the NAT equations as a consequence of the presence of higher order aberrations. The retrieved analytical expressions are verified through surface fitting to real ray-trace data obtained for a simple optical system. (c) 2020 Optical Society of America under the terms of the OSA Open Access Publishing Agreement

2020

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