Apochromat

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

Imaging of Extended Objects Using a Curved Holographic Lens Free From Spherical Aberration

Abstract: This paper evaluates the performance of an off-axis curved holographic lens using a numerical ray-tracing procedure The hologram curvature has been suitably selected to eliminate spherical aberration Light intensity distribution in the aberration spot observed at the Gaussian image plane has been evaluated for different object fields The images of extended coherent and incoherent edge as well as bar objects have been computed and the results compared with that for the aberration-free case All the results are illustrated in graphical form

The Design And Performance Of Aspheric Ophthalmic Lenses.

Abstract: The significant aberrations in ophthalmic lenses are (oblique) astigmatism (spectacle lenses) and spherical aberration (contact and intra-ocular lenses). In many cases, they cannot be eliminated or sufficiently controlled by bending. Fortunately, aspherizing one or both surfaces allows much greater control over either of these aberrations and in the case of contact and intra-ocular lenses, allows the balancing of the spherical aberration in the eye itself.

Studies on the Image Formed by Lenses. II. The Effect of Spherical Aberration on Optical Images

Abstract: The location of the best focuses and the image quality of lenses with spherical aberration were determined by measuring the intensity distribution of light in the line image, and the results were compared with the theoretical results obtained by wave optics.In the presence of primary spherical aberration, S1≡δsm/(F2λ) is introduced as a parameter, where δsm is the marginal spherical aberration, F is the f-number, and λ is the wavelength. The best focus lies: (1) midway between the paraxial and marginal foci for S1 36.In the presence of primary and secondary spherical aberration with the maximum value δsz, the location of the best focuses, δf0 measured from the paraxial focus and the definition |Γ|2 for the line image at the corrected aperture F0, are given by a parameter S2≡δsz/(F02λ) as ∣Γ∣2=1-1.955×10-4S22 δf0=0.80δsz for S2 45.The best type of correction for a given value of the secondary coefficient of aberration are also discussed.

Spherical aberration gauge for human vision.

Abstract: Spherical aberration affects vision in varying degrees depending on pupil size, accommodation, individual eye characteristics, and interpretations by the brain. We developed a spherical aberration gauge to help evaluate the correction potential of spherical aberration in human vision. Variable aberration levels are achieved with laterally shifted polynomial plates from which a user selects a setting that provides the best vision. The aberration is mapped into the pupil of the eye using a simple telescope. Calibration data are given.

Analysis of imaging properties of active lenses with spherical surfaces of independently variable curvature

Abstract: This work presents an algebraic analysis and computer simulations of imaging properties of a refractive tunable-focus fluidic lens with two continuously variable radii of curvature. Such lenses make possible to change aberration properties. It is shown that such a tunable-focus lens makes possible to correct simultaneously its spherical aberration and coma, which is not possible with the conventional fix-focus lens. Formulas are derived for the calculation of paraxial parameters and Seidel aberration coefficients of the lens. Imaging properties are demonstrated on several examples.