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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Journal Article•
TL;DR: In this article, lens aberrations are characterized in terms of the spherical and chromatic aberration of focal length f and focal distance g. The results are corroborated by computer data for electrostatic lenses and by experimental results.
5 citations
TL;DR: In this article, a novel adaptive lens with two degrees of freedom was proposed for axial scanning and aberration correction in confocal microscopy, which enabled both axial scan and correction of spherical aberrations.
Abstract: Deformable mirrors are the standard adaptive optical elements for aberration correction in confocal microscopy. Their usage leads to increased contrast and resolution. However, these improvements are achieved at the cost of bulky optical setups. Since spherical aberrations are the dominating aberrations in confocal microscopy, it is not required to employ all degrees of freedom commonly offered by deformable mirrors. In this contribution, we present an alternative approach for aberration correction in confocal microscopy based on a novel adaptive lens with two degrees of freedom. These lenses enable both axial scanning and aberration correction, keeping the setup simple and compact. Using digital holography, we characterize the tuning range of the focal length and the spherical aberration correction ability of the adaptive lens. The operation at fixed trajectories in terms of focal length and spherical aberrations is demonstrated and investigated in terms of reproducibility. First results indicate that such adaptive lenses are a promising approach towards high-resolution, high-speed three-dimensional microscopy.
5 citations
Patent•
20 Nov 1992
TL;DR: In this paper, the authors proposed a high magnification apochromat microscope objective lens which has such a high numerical aperture as NA 1.4, and is constituted so that a spherical aberration, a chromatic aberration and a curvature of image can be corrected satisfactorily.
Abstract: PURPOSE:To provide the high magnification apochromat microscope objective lens which has such a high numerical aperture as NA1.4, and is constituted so that a spherical aberration, a chromatic aberration and a curvature of image can be corrected satisfactorily. CONSTITUTION:This lens is constituted of a first group G1 of a plano-convex lens or a plano-convex having the joining surface whose strong convex surface is turned to an image side, a second group G2 of positive refracting power, a third group G3 containing a cemented lens, a fourth group G4 containing a meniscus lens of positive refracting power whose convex surface is turned to an object side, a fifth group G5 of negative refracting power, and a sixth group G6 containing a cemented meniscus lens whose convex surface is turned to the image side, and when f5, f6 and (f) denote focal distances of a fifth group G5, a sixth group G6, and the whole system, respectively, this high magnification microscope objective lens satisfies the following conditions. (1): ¦f5/f¦ 15.
5 citations
21 Nov 2005
TL;DR: In this paper, a zoom camera was constructed based on two adjustable lenses, and special liquids were required to prevent chromatic aberrations for all zoom levels and object positions, which made an achromatic design complicated.
Abstract: A zoom camera was constructed based on two adjustable lenses. The strongly varying lens shapes make an achromatic design complicated. Special liquids are required to prevent chromatic aberrations for all zoom levels and object positions
5 citations
TL;DR: Numerical results show that, when the coefficient of the spherical aberration is negative, one can obtain flattened laser irradiance at two positions along the focused field.
Abstract: Expressions for describing Gaussian beams focused by a lens with spherical aberration have been derived. Numerical results show that, when the coefficient of the spherical aberration is negative, one can obtain flattened laser irradiance at two positions along the focused field. The larger the coefficient of negative spherical aberration, the larger the flatness is. The effect of the Fresnel number of the focusing lens on the flattened laser irradiance is also investigated.
5 citations