Showing papers on "Apochromat published in 2003"

On- and off-eye spherical aberration of soft contact lenses and consequent changes of effective lens power.

Abstract: :Background.Soft contact lenses produce a significant level of spherical aberration affecting their power on-eye. A simple model assuming that a thin soft contact lens aligns to the cornea predicts that these effects are similar on-eye and off-eye.Methods.The wavefront aberration for 17 eyes

Projection lens system

Abstract: A compact and light-weighted projection lens system that is capable of projecting an image at an angle as wide as 75 degrees with sufficient field angle and brightness as represented by F number of approximately 2.4, that is capable of effectively correcting chroic aberration of magnification and aberration of distortion and exhibiting optical stability against environmental variations, and that is suitable for obtaining an extraordinarily fine image by the magnification and projection. In the projection lens system that comprises first to third groups of lenses in the order from the closest a magnified image where the first lens group of negative refractive power includes one or more aspherical lenses each having an aspherical plane on one or both of the surfaces, the second lens group of positive refractive power includes one or more positive lenses, and third lens group of positive refractive power includes one or more cemented triplet lenses comprised of three lenses of positive, negative, and positive attributes joined in this order, a projection lens system is characterized by terms and conditions defined as in the following formulae: 0.9<| f 1 |/ f <1.4 (1) 2.1< f 2 / f <3.4 (2) 1.9< f 3 / f <2.8 (3) where f is a total focal length throughout the projecting lens system, f 1 is a focal length of the first group of lenses, f 2 is a focal length of the second group of lenses, and f 3 is a focal length of the third group of lenses.

Optical system and method for fabricating a holographic optical element

Abstract: A simple, compact optical system is provided that includes a transmissive optical element and a HOE but that nevertheless does not require an extra optical element for the correction of chromatic aberration. The HOE is designed to have diffractive efficiency for each of R, G, and B light beams and have different focal lengths for those light beams so as to correct the longitudinal chromatic aberration produced by a rectangular parallelepiped prism. This eliminates the need for an extra means for correcting the chromatic aberration produced by the prism. The HOE may be designed to exhibit different angles of diffraction for the R, G, and B light beams so as to correct the chromatic aberration produced perpendicularly to the optical axis by a wedge-shaped prism.

Dialyte-refractor design for self-correcting lateral color

Abstract: Unlike traditional refracting telescopes, dialyte and Schupmann-medial refractors manage the correction of chromatic aberration through the use of correcting elements well spaced from their companion, single-element objectives. Dialyte designs leave a large contribution to lateral color, and Schupmann-medial types require the tilting of the mangin corrector to make the focus available, which restricts the field unless at least one toroidal curvature is included. A new dialyte design that combines attributes of both systems results in an all-refractive telescope that offers correction for lateral color and an accessible field unrestricted by tilt-induced astigmatism. The design can also be adapted to correct the secondary spectrum of a traditional achromat.

Liquid immersion apochromatic microscope objective lens

Abstract: PROBLEM TO BE SOLVED: To provide a liquid immersion apochromatic microscope objective lens which can maintain the flatness of an image plane over the entire part of a visual field and is to be well corrected in various aberrations while maintaining a magnification of about 60 times and a large NA of 1.4 without forming a lens group of the extreme image side to a Gauss type. SOLUTION: The objective lens is provided, successively from an object side, with a first lens group G1 including a cemented planoconvex lens G11 of a planoconves lens L11 with the plane nearly directed to the object side and a negative meniscus lens L12 with the concave face directed to the object side, a second lens group G2 including a cementing surface having negative refracting power and converging the luminous flux past the first lens group G1 to a convergent luminous flux and a third lens group G3 having at least two or more (G31, G32, G33) cemented lenses formed by directing their concave surfaces to the image side and satisfies respective conditions. COPYRIGHT: (C)2004,JPO

Projection lens system for image projection apparatus

Abstract: A projection lens system for an image projection apparatus that enhances the image aberration correction rate to achieve high resolution and luminance. The lens system includes a first lens group having first and second spherical lenses of positive refraction power movable along an optical axis, a second lens group having a third doublet lens formed with a lens of positive refraction power and a lens of negative refraction power in junction to correct chromatic aberration, and a fourth spherical lens to correct spherical aberration, a third lens group having lenses of positive refraction power, and a fourth lens group for correcting distortions having a seventh spherical lens being concave on both surfaces thereof, an eighth spherical lens of negative refraction power having a concave surface on one side and a convex surface on the other side, and a ninth lens of negative refraction power having an aspheric surface.

Hybrid achromatic spectacle lens

Abstract: Spectacle lens is a very particular optical imaging element of great practical importance. Although its construction is very simple some demands are specific (in particular remarkable shift of output pupil). A number of classic spectacle lens designs is known for long time, however some new possibilities of aberration correction appear if we use a hybrid (diffractive refractive). Hybrid lens is an optical system composed of a classic refractive (glass) lens and a diffractive microstructure deposited on one of its surfaces. Imaging properties of such lens can be expressed in terms of dimensionless parameters(formula available in paper)(describing the distribution of focusing power between diffractive and refractive part). By proper choice of parameter η we can compensate chromatic aberration. Thanks to other free parameters spherical aberration and astigmatism can be corrected also what is reasonable choice for spectacle lens. In this contribution the possibilities of particular Seidel aberration correction of hybrid lens will be presented. As an illustration some examples of spectacle hybrid lenses will be shown and its imaging characteristics compared with imaging characteristics of commercially available refractive lenses.

Chromatic aberration correction for ultraviolet and visible light optical system has beam splitter separating visible light from ultraviolet and additional correction lenses in visible light path

Abstract: The microscope for mask and integrated circuit wafer inspection system has an objective lens (1) close to the wafer (5). The multiple element objective lens is optimized for correction of chromatic aberration at ultraviolet wavelengths of 157,193 and 248 nm. Visible light or infrared light e.g. at 650-820 nm is used for an autofocus system. The ultraviolet passes straight through a beam splitter (6) and goes directly to a detector (2). Visible or infrared light is reflected from the beam splitter and passes through two additional chromatic aberration correction lenses (7,3) and is brought to a focus (4).

Athermal optical glasses and thermally stable space-based apochromats (from the materials of a report at the International Conference ??Applied Optics?2002")

Abstract: A basis is provided for choosing thermooptical parameters V and W1R as the true criteria of athermal glasses that minimize temperature distortions in space-based objectives. Previously unpublished results are presented from our studies, involving the calculation of the spectral and temperature dependences of V and W1R, and a detailed summary is given of the thermooptical, optical, and operating parameters of Russian and foreign athermal optical glasses. It is shown that the set of Russian athermal glasses makes it possible to actively intervene in the process of controlling thermal-wave aberrations and to develop an optical system for an objective-apochromat that has a high degree of correction of chromatic aberrations and is nonmisalignable in a variable temperature field. The calculated characteristics are given for thermally stable long-focus apochromatic objectives developed by the authors that are more stable against dynamic external actions and have 20-30% higher image quality than apochromats made from nonathermal glasses. This reduces the requirements on their thermal protection and mass.

Plan apochromatic microscope objective

Abstract: The invention relates to a plan-apochromatic microscope objective. DOLLAR A Such a microscope objective comprises five lens members with a total of ten lenses. Seen from the object plane, the first link with a positive overall focal length contains a lens, the center of the radius of curvature of which is located on the object side. The second link consists of two lenses cemented together which - seen from the object level - have a "negative-positive" refractive power sequence with a positive overall focal length. The refractive power difference between the first and the second link is less than 25%. The third link consists of two lenses of the refractive power sequence "negative-positive" cemented together with a total focal length of more than 50 mm. The fourth link consists of three lenses cemented together with the refractive power sequence "positive-negative-positive" with a positive overall focal length of at most 35 mm. The amount of the focal length of the middle lens is smaller than the respective amounts of the focal lengths of the outer lenses. The fifth link consists of two lenses of the refractive power sequence "positive-negative" cemented together with a total negative focal length between -20 mm and -8 mm.

Analysis of chromatic aberration of single objective lens and correction of that of a NA=0.85 objective lens.

Abstract: The chromatic aberration of single lenses is analyzed by using paraxial theory. Thicker lenses showed better performances not only chromatic aberration but also other performances.

Ophthalmic lenses with reduced chromatic aberration

Abstract: The present invention provides single vision and multifocal hybrid ophtalmic lenses, as well as methods for their production, having the transverse chromatic aberration of the retractive element reduced by the diffractive element.

Spherical aberration compensation by wavelength

Abstract: A method for minimizing spherical aberration in an optical read/write drive caused by variances in lens thickness and laser wavelength. The method provides an economic solution that pairs objective lenses with laser diodes such that the spherical aberration caused by the objective lens is offset by the spherical aberration caused by the laser wavelength, thereby minimizing or completely canceling the overall spherical aberration.