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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5 citations
Patent•
28 Sep 2011
TL;DR: In this article, a 100*CaF2-excluding plan apochromatic metallographic microobjective consisting of eight lenses which are divided into three light sets and arranged coaxially is presented.
Abstract: The invention discloses a 100*CaF2-excluding plan apochromatic metallographic microobjective which comprises lenses. The metallographic microobjective is characterized by being composed of eight lenses which are divided into three light sets and arranged coaxially; the lenses comprise a convex lens, a concave lens, a concave lens, a convex lens, a concave lens, a convex lens, a convex lens and an aplanatic thick meniscus lens which are sequentially connected; and the lenses do not contain CaF2. Compared with the domestic and overseas similar objectives, the microobjective disclosed by the invention has the advantages of no CaF2, less lenses, simple structure and assembling and adjusting processes, low cost, high performance-price ratio, and the like; and the performance indexes of the microobjective are better than those of the existing CaF2-containing similar objectives made of TF3 special glass, therefore, the microobjective disclosed by the invention has the advantages of broad application prospect and high commercial value.
5 citations
TL;DR: It is found that with the increment of the layer number, the spherical and oblique aberrations can be corrected up to higher orders though the corresponding ranges of the refractive indices and working distances become narrower.
Abstract: A study of the corrections for some low-order aberrations of multilayer flat lenses based on the introduction of negative-index materials is presented. With the aberration coefficients of a multilayer flat lens that we provided, numerical solutions for the parameters of the double-layer three-layer, and four-layer flat lenses are investigated, respectively, to correct the aberrations, under some conditions, up to orders as high as possible. We find that with the increment of the layer number, the spherical and oblique aberrations can be corrected up to higher orders though the corresponding ranges of the refractive indices and working distances become narrower.
5 citations
Patent•
31 May 1996
TL;DR: In this article, a microscopic objective lens of an apochromatic grade having magnification of about 20, a large numerical aperture, excellent contrast and resolving power and very flat image plane over a wide visual field is presented.
Abstract: PURPOSE: To provide a microscopic objective lens of an apochromatic grade having magnification of about 20, a large numerical aperture, excellent contrast and resolving power and very flat image plane over a wide visual field. CONSTITUTION: This lens is composed of a first lens group G1 of a positive refractive power having a meniscus component whose concave surface confronts the object side, a second lens group Q2 composed of a joined lens of a negative lens, a positive lens and a negative lens transmitting the exit light beam from an object through the first lens group G1 as a divergent light beam, a third lens group G3 of a positive refractive power converging the divergent beam to a convergent beam, a fourth lens group G4 composed of a joined meniscus lens whose convex surface confronts the object side and a fifth lens group G5 composed of a joined meniscus lens whose concave surface confronts the object side and the condition prescribing the ratio of the respective radii of curvature of the surface closest to the image side of the first lens group G1 and the surface closest to the object side of the second lens group G2 and the condition prescribing the refractive power of the third lens group G3 are satisfied.
5 citations
18 Feb 2004
TL;DR: In this paper, a fast (F/155) and wide angle camera objective for large spectral coverage, from UV to VIS and up to NIR, when a large-size CCD is used on the focal plane of the spectrograph of the Mont Megantique telescope.
Abstract: All-reflective optics is conventionally required for extended spectral region observations in astronomical spectrograph But the spatial resolution is usually not good enough while the large-size CCD will be used for observation in all-reflective optics In this paper, all-refractive optics has been investigated to design a fast (F/155) and wide angle camera objective for large spectral coverage, from UV to VIS and up to NIR, when a large-size CCD is used on the focal plane of the spectrograph of Mont Megantique telescope The case of achromatic and apochromatic condition has been investigated for axial and lateral color controls The new proposed solutions have been optimized from two to three different glass combinations in order to have higher throughputs for large spectral coverage, especially in UV region The used components have been minimized to reduce the light inherent lost The monochromatic aberrations have been corrected and controlled by using optimized lens bending and shapes to make the camera have the CCD pixel resolution Ray tracing results displayed the good optical performance of the camera to cover from 350 nm to 1000 nm spectral region with high resolution The broadband AR coating, enhanced on UV region, will be used on each surface of the lenses in the camera Final throughputs for the designed camera has been estimated and given in the paper
5 citations