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Apochromat

About: Apochromat is a research topic. Over the lifetime, 642 publications have been published within this topic receiving 7934 citations.


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Proceedings ArticleDOI
22 Sep 1995
TL;DR: In this article, the authors compared approaches for making the lenses thinner and techniques for correcting chromatic aberrations and showed that polychromatic MTF and chromatic correction can not be achieved.
Abstract: In some white-light imaging applications it is desirable to make the optical elements extremely thin. Numerous practical advantages are derived if the lenses are one to two orders of magnitude thinner than conventional refractive lenses. For example, these lens systems provide minimal weight and compactness, and are potentially low cost. Although diffractive lenses are only a few microns thick, they have severe chromatic aberrations. Approaches are compared for making the lenses thinner and techniques are examined for correcting chromatic aberrations. There are basic limits to the polychromatic MTF and chromatic correction that can be achieved.
Proceedings ArticleDOI
30 Jun 1998
TL;DR: In this article, an apochromatic interferometer for VUV wavelengths was proposed and the benefits and also the technological problems which come along with the use of VUV wavelength are discussed.
Abstract: To improve the resolution and the sensitivity of optical metrology an interferometer for VUV wavelengths was realized. To examine the influence of the wavelength especially with regard to the period of the object structure, an apochromatic design was chosen. This means an object can be measured with wavelength from 157nm up to 900nm without changing the optical setup. The design of this interferometer will be presented. The benefits and also the technological problems which come along with the use of VUV wavelengths are discussed. Further problems occur when deep binary structures are measured. An overview of those problems will be given and the use of white light interferometric methods to overcome those problems will be discussed. Measurements have been performed with different light sources. The wavelength scale is extended from the visible to the deep UV, the coherence properties of the sources are very dissimilar and the interferograms are evaluated with different techniques. The experimental results will be presented and discussed.© (1998) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Proceedings ArticleDOI
25 Jul 2010
TL;DR: In this article, the chromatic aberration of these nanoslits lenses by using the finite-element method in conjunction with the perfectly matched layers is analyzed in detail, and the effect of the matched layers on the aberration is shown.
Abstract: Metallic-dielectric lenses permit sub-wavelength focusing of light in the visible and near-infrared. The chromatic aberration of these nanoslits lenses by using the finite-element method in conjunction with the perfectly matched layers is analyzed in detail.
Proceedings ArticleDOI
24 Oct 2000
TL;DR: In this article, a technique is described in which a spherical concentric Cassegrain-like primary-secondary combination is followed by a simple catadioptric focal modifier, and the final focus is f/5 with a sub-arcsecond resolution over a 5 arcminute angular field for a passband of 480-850nm.
Abstract: Several large telescopes are now being proposed that would benefit from the cost reduction due to the use of spherical primary mirror. However, structural cost constraints require compact formats that tend to impose very high speeds, e.g. f/1.5, which renders difficult the correction of the resulting very large spherical aberration. A technique is described here in which a spherical concentric Cassegrain-like primary-secondary combination is followed by a simple catadioptric focal modifier. The spherical primary is 9m diameter, f/1.5, and the final focus is f/5 with a sub-arcsecond resolution over a 5 arcminute angular field for a passband of 480-850nm. Primary- secondary separation is only 11m and central obscuration is only 11% of pupil area. The two relatively small corrector components provide the functions of concentric meniscus and zonal corrector plate and are made from the same single glass- BK7 is the example given, but silica or any other preferred glass is possible. The relatively small zonal corrector is the only aspheric surface in the entire system. A related system is described elsewhere in which a 30 arcminute angular field can be achieved with a similar resolution, but with more complex glass requirements. However, supply of such exotic glasses may be difficult in large diameters, and the system presented here may find a place in some specialized applications.© (2000) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Book ChapterDOI
01 Jan 1972
TL;DR: In this article, images reconstructed from long-wavelength holograms have aberrations as a result of large construction to reconstruction wavelength ratios, which may seriously degrade image resolution due to the large number of spherical aberrations.
Abstract: Images reconstructed from long wavelength holograms have aberrations as a result of large construction to reconstruction wavelength ratios. For many practical recording geometries, these aberrations of which spherical aberration is often the largest may seriously degrade image resolution.

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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
20214
20204
20196
20188
201716
201625