Abstract: A beam shaping system for an astigmatic light source utilizes two lenses, both having diffractive power. A first lens shapes the beam in a first dimension and a second lens shapes the beam in a second dimension perpendicular to the first.

Abstract: A lens according to the invention has diffractive power and two primary foci, where one focus is associated with the first diffractive order and one with the second diffractive order.

Abstract: A diffractive optical element and a method to produce same is disclosed. The optical element comprises a base and at least first and second phase zones wherein the first phase zone comprises a first multiplicity of steps and the second phase zone comprises a second multiplicity of steps and wherein the first multiplicity and the second multiplicity of steps are different. The method to produce the diffractive optical element of the present invention includes the step of defining a collection of masks for creating stepped phase zones wherein at least one of the collection of masks partially masks out at least one phase zone such that the at least one phase zone will be partially etched.

Abstract: The method utilizes high resolution lithography, mask aligning, and reactive ion etching. In particular, at least two binary amplitude masks are generated. A photoresist layer on an optical element substrate is exposed through the first mask and then etched. The process is then repeated for the second and subsequent masks to create a multistep configuration. The resulting optical element is highly efficient.

Abstract: A plurality of binary diffractive optic lenses are formed in the surface of one substrate and a corresponding plurality of recesses are formed in the surface of another substrate. The binary diffractive optic lenses on one substrate are aligned with the recesses on the other substrate and the two substrates are bonded together. A plurality of individual binary diffractive optic lens cover assemblies are obtained by dicing the two bonded substrates.

Abstract: Vision correcting lenses utilizing the principles of both Fresnel lenses and Fresnel zone plates are disclosed. The lenses of the present invention provide multifocal vision correction, and are most preferably used to provide intraocular lenses for small incision surgeries. Using the concept of a "tuned" Fresnel lens, intraocular and other types of vision correcting lenses are provided by the present invention which overcome the limitations found in typical Fresnel lenses by phase synchronizing the light passing through the lens. As disclosed, the groove width and depth of the lens may be varied to provide the synchronization, and also to provide multifocal vision. Also, the design of the present invention permits a relatively thin lens to be designed, therefore making it particularly applicable to small incision surgeries since it may be rolled or folded into a configuration which is easily inserted into an incision in the eye.

Abstract: An image reading apparatus comprises a plural-line sensor comprising a plurality of one-dimensional sensor arrays disposed on one and the same substrate, an imaging optical system for imaging an object on the sensor, and a brazed diffraction grating disposed in the optical path between the imaging optical system and the sensor for color-resolving a light beam from the object into a plurality of lights and directing the color-resolved lights to the sensor arrays corresponding thereto, the number of steps of the staircase structure of the diffraction grating being four or more.

Abstract: A high-efficiency, diffractive optical element having at least one surface including multilevel steps, the steps determined by calculating equiphase boundaries utilizing a disclosed equation and algorithm. The optical element can be adapted to correct for chromatic and/or spherical aberration, and can be used in UV lithographic apparatus.

Abstract: A transmission grating is used to reduce chromatic aberration in a Fresnel lens, wherein the lens chromatic dispersion is offset and substantially canceled by the grating's diffraction-induced dispersion. The grating comprises a Fresnel-type pattern of microscopic facets molded directly into the lens surface. The facets would typically have a profile height of around 4.multidot.10.sup.-5 inch and a profile width of at least 10.sup.-3 inch. In its primary intended application, the invention would function to improve the optical performance of a Fresnel lens used to concentrate direct sunlight.

Abstract: An optical system, that includes a light source having sufficient coherency to provide a predominate operating wavelength and a diffraction grating lens system to focus the light from the light source to an image point on the optical axis of the optical system, provides for change of position of the image point along the optical axis over a wide focusing range with suppression of generated aberration. In particular, the optical system comprises a light source both movable in the direction of the optical axis and capable of variation in wavelength and a diffraction grating lens system that condenses the beam from the light source onto an image point on and along the optical axis, which system is effective in cancelling out aberration generated due to movement of the light source.

Abstract: Apparatus for correcting spherical aberration of light reflected from a surface of an information-bearing layer of an optical disk and traversing through a substantially transparent substrate layer, overcoating the information layer, prior to traversal of a multi-element objective lens means, uses a correction lens assembly having several lens elements, with a variable air gap between the adjacent surfaces of a sequential pair of the lens elements. Information about the nominal thickness of an optical disk from which optical energy is then being reflected is obtained, and used to adjust the thickness of the air gap, to correct the additional spherical aberration caused by the change in covering substrate thickness and change the definition of the corrected spot to approach the definition of a spot obtained with a covering substrate of exactly the nominal value.

Abstract: A multifocal ophthalmic lens includes first and second lens members. Each lens member has a smooth outer surface and an inner surface with an edge about its perimeter. A multifocal diffractive zone plate on at least one of the lens members is characterized by an index of refraction. The lens members are joined at the edges by ultrasonic welding to form a cavity adjacent the diffractive zone plate. The cavity is filled with a liquid medication having an index of refraction which is different than the index of refraction of the diffractive zone plate. A hole through one of the lens members functions as a fluid transport mechanism to permit transfer of the medication between the cavity and eye.

Abstract: In accordance with the present invention, a BOE-corrected, off-axis image forming apparatus is disclosed. The apparatus has a first stage with a primary reflective element disposed to reflect light incident from an entrance pupil of the apparatus and form a real image at an intermediate image plane, and a second stage located off-axis with respect to the first stage. The second stage is defined by a secondary reflective and/or refractive assembly which re-images light from the intermediate image plane to a final image plane. A binary optical element (BOE), which has higher-order optical characteristics for providing aspheric correction but extremely low optical power, is provided in one of the stages for correcting aberrations introduced by the other optical elements in the apparatus. The BOE contributes no more than about 3% of the optical power provided by the stage which contains the BOE.

Abstract: A fresnel lens in which each of the facets is so dimensioned and configured that the distance between the facet and a focal point of the lens is (n+k) .lambda. where n is an integer, .lambda. is the wavelength of the radiation passing through the lens, and k is a fraction between 0 and 1 which is substantially constant for any facet over the entire face of the lens. Preferably the lens comprises a plurality of zones, each comprising a number of facets, the integer n being constant for each facet of each said zone, but being different for facets of different zones.

Abstract: In one embodiment, a three-element biocular eyepiece system 40 having a first optical element 42 with at least one diffractive surface 44, a second optical element 48 having a refracting convex surface 50 and a refracting concave surface b 52 is provided. A third optical element 54 having a refracting convex surface 56 and a refracting convex surface 58 is also employed. In another embodiment, a four-element biocular system 60 is disclosed as having an optical element 62 having a refracting concave surface 64 and a refracting convex surface 66, a refractive-diffractive hybrid optical element 68 having a diffractive surface 70 and a refracting convex surface 72, an optical element 74 having a refracting convex surface 76 and a refracting concave surface 78, and an optical element 80 having a refracting concave surface 82 and a refracting convex surface 84. The diffractive surfaces 44 and 70 have a kinoform profile 102 a-d or approximated kinoform profiles 112a-d and 122a-d.

Abstract: A binary optic lens is designed to achieve a predetermined effect on light propagating through the lens by specifying an initial lens design with a plurality of discontinuous subaperture regions, assigning each subaperture region a relative phase difference of 0 or .pi., and calculating the net intensity of light propagating through the lens by coherently summing the wave amplitudes for all of the subaperture regions at a given point in the image plane of the lens. The assigned phase difference for one of the subaperture regions is then changed and the intensity is recalculated by coherently summing the wave amplitudes for all of the subaperture regions at the given point. If the intensity increases over the previously calculated intensity, the changed phase difference is assigned to the selected subaperture region. The steps of changing, recalculating, and assigning are repeated for all of the subaperture regions to make one complete pass through the lens.

Abstract: A bifocal lens of the Cohen lens design utilizing phase zone plate optics and a facet depth of one-half wavelength of the design wavelength, where the primary focal points are at two orders, specifically the 0.sup.th and 1.sup.st orders, and the brightness at each primary focal point is equal at about 0.40.

Abstract: In a reflective photosensor in which a light emitting element and a light receiving element are disposed in a mold resin, a planar optical element (micro Fresnel lens) including a first lens section for projecting a light emitted from the light emitting element toward a sense object in an external space and a second lens section for introducing a reflection light reflected from the sense object to the light receiving element is arranged in the mold resin. Favorably, the light emitting element is a light emitting diode of an edge emitting type and is set in a posture in which the element lies on its side. A reflection mirror is disposed in the model resin to introduce a light emitted from the light emitting diode to the first lens section.

Abstract: An ophthalmic lens exhibiting diffractive power has a plurality of diffractive zones and smooth surfaces. The zones are arranged such that R.sub.0.sup.2 does not equal R.sub.1.sup.2 -R.sub.0.sup.2 where R.sub.0 is the radius of the central zone and R.sub.1 is the radius of the first annular zone.

Abstract: An optical element for converting a uniform beam of light of wavelength .lambda. into an array of illuminated spots, the optical element including a phase plate made of an array of constant phase zones; and an image plane disposed parallel to and at a preselected distance from the phase plate, the preselected distance being selected so that illuminating the phase plate with uniform coherent illumination of wavelength .lambda. produces the array of illuminated spots on the image plane, the spot array having a fill factor in at least one dimension that is less than 1/2.

Abstract: An optical element having a substrate and a composite grating pattern formed thereon. The pattern is constituted with two different kinds of grating patterns superimposed on the substrate. When one of the two kinds of grating patterns is formed in a Fresnel lens pattern, a light focusing or collimating function (i.e. a lens function) is implemented. When the other pattern is formed in an equally separated linear grating pattern, the optical element develops the lens function and a function to diffract lights through the linear grating. When one of the two kinds of grating patterns is formed in a Fresnel lens pattern and the other pattern is implemented in an unequally separated linear grating pattern, a lens function to focus lights onto a point and a cylindrical lens function to focus lights in a linear contour are obtained. Consequently, when parallel lights are incident to the optical element, there occurs astigmatism.

Abstract: An optical device suitably employable in intraocular and contact lenses that employs a phase zone plate of a Cohen lens design that relies on a small number of zones to provide multifocal images.

Abstract: A bifocal lens of the Cohen lens design utilizing phase zone plate optics and a facet depth of one-half wavelength of the design wavelength, where the primary focal points are at two orders, specifically the 0.sup.th and 1.sup.st orders, and the brightness at each primary focal point is equal at about 0.40.

Abstract: A multifocal optical device is provided for focusing light traveling parallel to an optical axis of the device. The multifocal optical device comprises a multifocal phase zone plate including at least two annular zones disposed substantially concentrically about the optical axis and spaced in a radial dimension from the optical axis in proportion to the square root of q, where q is an integer zone number; and an absorbing material disposed on a portion of ones of the annular zones for absorbing a portion of the light.

Abstract: A multifocal ophthalmic lens has diffractive power produced by a plurality of concentric zones. The zones have radii that meet the conditionR.sub.0.sup.2 is not equal to R.sub.1.sup.2 -R.sub.0.sup.2where R.sub.0 is the radius of the central zone and R.sub.1 is the radius of the first annular zone.

Abstract: A diffraction bifocal lens or lens system, comprising two profiled surfaces or interfaces or a linear combination thereof, wherein one profile provides for the bifocality of the lens and the other profile compensates for chromatic aberration. These lenses or lens systems exhibit two focal points, one which exhibits positive chromatic aberration and the other which exhibits negative chromatic aberration.

Abstract: An artificial eye lens such as a contact lens or intra-ocular lens corrects astigmatism by two sets of substantially linear parallel zones arranged to diffract light predominantly into one order at one orientation, the spacing of the zones diminishing on either side of the linear axis. In addition circular diffraction zones may be provided to give both spherical and cylindrical power for astigmatism correction.

Abstract: A diffraction grating comprises the plurality of grating rings provided at positions such that their radii r are selected so that a function .phi.(r) of r satisfies the following differential equation and initial conditions, ##EQU1## where .lambda. is the wavelength of a scanning light beam, f is the focal length of the diffraction grating, r is the radius from the center of diffraction grating, M is the distance from the diffraction grating to a scanning surface expressed as a multiple of the focal length f, and moreover the relation.phi.(r)=n+.phi.(0)n=0, 1, 2, . . .(n is a non-negative integer)is satisfied.

Abstract: Partially recessed microlenses (31, 32; FIG. 3) are made in a substrate (10) by a technique including the steps of forming a hard-baked patterned layer (21, 22, 64, FIG. 2) on a surface of the substrate, this patterned layer having at least one island portion (21, 22) surrounded by an auxiliary portion (64), and simultaneously etching this hard-baked patterned layer and the substrate to remove at least a portion of the thickness of the hard-baked layer. The island portions are located at areas overlying where microlenses are desired. The volume of the auxiliary portions of the hard-baked patterned layer is advantageously significantly greater than that of the island portions.Full recessed microlenses (31, 32; FIG. 6) are made by adding a step in the above technique, namely, the step of forming another hard-baked patterned layer (94) covering only the auxiliary portions of the above-mentioned patterned layer prior to the etching.

Abstract: There is disclosed a diffractive optical element and a method to produce same wherein the element comprises a base and at least one phase zone comprising an arbitrary multiplicity M of steps of generally identical step height, wherein M is not a power of 2. The method includes the steps of defining a basic depth unit equivalent to a zone height divided by M, defining a depth sequence of N depths wherein N is the smallest integer greater than log.sub.2 M such that each of the M steps can be produced by at least one linear combination of the N depths, defining N masks herein each mask enables the optical element to be processed to one of the N depths and wherein for each mask, the steps to be processed are those which have the one of the N depths in its linear combination and serially utilizing each of the N masks for processing of the optical element.

Abstract: A broadband diffractive lens or imaging element produces a sharp focus and/or a high resolution image with broad bandwidth illuminating radiation. The diffractive lens is sectored or segmented into regions, each of which focuses or images a distinct narrowband of radiation but all of which have a common focal length. Alternatively, a serial stack of minus filters, each with a diffraction pattern which focuses or images a distinct narrowband of radiation but all of which have a common focal length, is used. The two approaches can be combined. Multifocal broadband diffractive elements can also be formed.

Abstract: A device for generating a second harmonic from a laser source is disclosed. The light from the laser passes through an optical fiber in which the second harmonic is generated. The light exiting from the optical fiber has a conical wave surface which is incident upon a collimating lens. Because the collimating lens has a diffraction lattice formed thereon, it is easy and efficient to collimate the second harmonic. It is also possible to decrease the size of the apparatus due to the use of the diffraction lattice formed on the collimator lens. This enable such a device to be particularly useful with a small sized light source such as a semiconductor laser.

Abstract: An ophthalmic contact lens with a phase plate and a pure refractive portion within its optic zone. The invention embraces an ophthalmic contact lens of the Cohen lens design with a phase plate and a pure refractive portion within its optic zone.

Abstract: An ophthalmic lens including a carrier lens having an anterior and a posterior surface. A zone plate is having a plurality of zones is disposed annularly about the optical axis of the carrier lens on at least one of the anterior or posterior sides. Each of the zones of the zone plate is spaced from the optical axis in proportion to the square root of n, where n is the zone number. At least one echelette is disposed in each of the zones, each of the echelettes having a surface through which light propagating along the optical axis traverses. The surface of the echelettes varies in a predetermined manner from the zone nearest the optical axis to the zone furthest from the optical axis so that as the size of the aperture disposed along the optical axis changes, the relative intensity of light diffracted to desired orders changes. A step is provided between each of the echelettes, the height of each step having substantially the same optical path length.

Abstract: An optical element (12) has aspherical (14) and binary grating (16) optical surfaces. In the preferred embodiment, the optical element (12) is a positive meniscus optical element made of germanium having a useful spectral bandpass in the infrared wavelength region. A telescope (100) includes a first positive meniscus optical element (102), having a convex aspherical surface (104) and a concave binary grating surface (106). A first negative meniscus optical element (107) having a concave binary grating surface (108) and a concave aspherical surface (110) is employed. Next is a positive power lens (112), followed by a second negative meniscus lens (118). In the preferred embodiment, the first negative meniscus optical element (107) and the positive power lens (112) are affixed to a common housing (124), which is removable from the telescope system. Removal of the housing (124) converts the telescope (100) system from a wide-field-of-view telescope (100) to a narrow-field-of-view telescope (40).