Topic
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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01 Jul 1990
TL;DR: Apochromatic Holographic Optical Elements (AHOEs) have been designed and developed using 633 nm wavelength in red sensitive photographic emulsion to work at 633nm 5 14 nm and 488 nm with same focal lengths and equal efficiencies at each wavelength as mentioned in this paper.
Abstract: Apochromatic Holographic Optical Elements (AHOEs) have been designed and developed using 633 nm wavelength in red sensitive photographic emulsion to work at 633 nm 5 14 nm and 488 nm with same focal lengths and equal efficiencies at each wavelength. These AHOES have been used for recognition of coloured targets and pseudocolouring.
09 May 2021
TL;DR: In this article, the authors demonstrate 3D-printed hybrid refractive/diffractive achromats and apochromats by using DOEs and simultaneously combining two different photoresists.
Abstract: We demonstrate 3D-printed hybrid refractive/diffractive achromats and apochromats by using DOEs and simultaneously combining two different photoresists. These combinations drastically reduce chromatic aberrations in 3D-printed micro optics for the visible wavelength range.
10 Apr 2007
TL;DR: In this article, the influence of the wavelength of light on values of wave aberration coefficients is discussed. And a technique for calculation of the dependence of chromatic coefficients on the wavelength, their interpretation and the connection to chromatic aberrations is proposed.
Abstract: Our work deals with the influence of the wavelength of light on values of wave aberration coefficients. It is proposed a technique for calculation of the dependence of aberration coefficients on the wavelength, their interpretation and the connection to chromatic aberrations. It is also shown the calculation of the Strehl definition using chromatic aberration coefficients and the tolerance limits are given. The proposed method for calculation of chromatic aberration coefficients is shown for the case of the imaging of axial point by the rotationally symmetrical optical system. Relations that enable calculation of chromatic aberration coefficients up to fifth order are carried out. These relations are accurate enough for most optical systems in practice.
Dissertation•
19 Dec 2012
TL;DR: In this article, a mathematical derivation and description of different kinds of chromatic aberrations accompanied with a variety of approaches to correct the chromatic effects in different levels is provided.
Abstract: The variation of refractive index with wavelength, known as dispersion, was what redirected Isaac Newton from refractive telescope designs toward a reflective one, since he found the chromatic effect incurable. Later it was shown that different materials demonstrate different chromatic characteristics and refractive optical elements can compensate each other’s chromatic contributions. This promoted the simple dispersion effect to the field of formulizing and categorizing chromatic aberrations and their corrections. In this study an introduction to this process is provided, where the historical aspects are followed by the mathematical derivation and description of different kinds of chromatic aberrations accompanied with a variety of approaches to correct the chromatic effects in different levels. The provided mathematical basis is employed in studying three distinctive topics. In the first one the flexibility of refractive elements is used to provide a middle-sized catadioptric telescope design with all-spherical surfaces. Employing a new combination of chromatic lens correctors, the image quality can be improved so that it becomes comparable to an equivalent aspheric Ritchey-Chrétien telescope design. As the second topic the atmospheric dispersion and its effect in extremely large telescopes are discussed, where a new atmospheric dispersion corrector design is proposed. In the third task the chromatic behavior in an inhomogeneous medium is considered. A new gradient refractive index lens model for the crystalline lens of the eye is established and a different approach in characterizing its chromatic effects is developed. These three research topics are underpinning the main goal of the theses, that is the role of chromatic aberration in image formation in various optical systems.
01 Jul 2016
TL;DR: A digital filtering technique that matches the focal lengths and the extents of the recorded RGB holograms is proposed to eliminate the chromatic aberration in full-color OSH.
Abstract: I investigate the chromatic aberration of full-color optical scanning holography (OSH) and propose a digital filtering technique that compensates the chromatic aberration. The focal lengths and the extents of Red, Green and Blue (RGB) time-dependent Fresnel zone plates (TD-FZPs) which encode the RGB complex holograms depend on wavelengths of RGB beams. This generates chromatic aberration in full-color OSH. A digital filtering technique that matches the focal lengths and the extents of the recorded RGB holograms is proposed to eliminate the chromatic aberration in full-color OSH.