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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TL;DR: In this paper, the authors investigate both the design performance and the as-built performance of two designs that incorporate kinoforms for the correction of axial chromatic aberration, which is on the order of the design wavelength.
Abstract: With the move to smaller pixel sizes in the longwave IR region there has been a push for shorter focal length lenses that
are smaller, cheaper and lighter and that resolve lower spatial frequencies. As a result lenses must have better correction
for both chromatic and monochromatic aberrations. This leads to the increased use of aspheres and diffractive optical
elements (kinoforms). With recent developments in the molding of chalcogenide materials these aspheres and kinoforms
are more cost effective to manufacture. Without kinoforms the axial color can be on the order of 15 μm which degrades
the performance of the lens at the Nyquist frequency. The kinoforms are now on smaller elements and are correcting
chromatic aberration which is on the order of the design wavelength. This leads to kinoform structures that do not
require large phase changes and therefore have 1.5 to just over 2 zones. The question becomes how many zones are
required to correct small amounts of chromatic aberration in the system and are they functioning as predicted by the lens
design software? We investigate both the design performance and the as-built performance of two designs that
incorporate kinoforms for the correction of axial chromatic aberration.
2 citations
TL;DR: In this paper, the paraxial chromatic aberration of combined asymmetrized quadrupole lenses has been investigated and it has been shown that the achromatism can be obtained also in the case of asymmetrisation, while for electrostatic or magnetic doublets the deflection can be independent of the particle energies.
2 citations
TL;DR: Two concentric, coaxial solenoids form an intermediate ring image with a cusped caustic enabling momentum selection to be made where the transverse aberration is of third order in aperture as discussed by the authors.
2 citations
01 Jan 2010
TL;DR: In this article, it was shown that a bend-free drift-quadrupole system can transport certain incoming beam ellipses without introducing first-order chromatic distortions, which is not a rare special case, but a general property.
Abstract: Though a straight drift-quadrupole system can not be made an achromat, there exists an example of a bend-free drift-quadrupole system which can transport certain incoming beam ellipses without introducing first-order chromatic distortions. In this paper we show that such a possibility is not a rare special case, but a general property. For every drift-quadrupole system there exists an unique set of Twiss parameters, which will be transported through that system without first order chromatic distortions. Moreover, we prove that at the same time these Twiss parameters minimize the absolute values of the system chromaticities and also bring the second order effect of the betatron oscillations on the longitudinal dynamics to the minimal possible value.
2 citations
Patent•
11 Jun 1990
TL;DR: In this article, an objective lens system for use with wavelengths in the visible spectrum, has first and second lens groups, and the first lens group has one aplanat lens and the second lens group is a doublet.
Abstract: An objective lens system for use with wavelengths in the visible spectrum, has first and second lens groups. The first lens group has one aplanat lens. The second lens group is a doublet. The second lens group is designed to correct for chromatic aberrations introduced by the first lens group. The power of the second lens group is inversely related to the index of refraction of the first lens group and the optical glasses of the lenses of the second lens group are selected to satisfy a novel color correction equation.
2 citations