Abstract: The angular and/or spectral bandwidth of a holographic lens assembly can be widened to accomodate highly diverging and/or wide spectral bandwidth illumination sources, respectively. Each lens in the lens assembly is comprised of a plurality of angularly customized holograms (an angularly customized hologram set). Each of the individual holograms in an angularly customized hologram set has an acceptance angle range that is centered on a discrete peak acceptance angle. The separation between the holograms' peak acceptance angles is chosen so that the acceptance angle ranges of the individual holograms overlap. The resulting cumulative acceptance angle range of each angularly customized hologram set provides a holographic lens assembly that has a wider angular bandwidth than prior holographic lenses.

Abstract: A confocal optical apparatus comprising a light source, a first aperture portion for passing light emitted from the light source and obtaining a point source, an objective lens for causing the light that has passed through the first aperture portion to converge on a measurement object, a second aperture portion located on a plane conjugate with the convergence surface on the measurement object, and light detectors for detecting light that has passed through the second aperture portion, wherein placing the first and second aperture portions in the same position and using them as the same aperture portion, as well as positioning the detection surfaces of the light detectors substantially on the same surfaces as the conjointly used identical aperture portions make it possible to reduce the size and weight of the apparatus, to perform three-dimensional shape measurements rapidly and accurately, and to facilitate the alignment of each portion.

Abstract: An improved holographic backlight and liquid crystal display system. The holographic backlight comprises a cold cathode fluorescent tube for providing white light, and a light pipe disposed to receive the white light. A phase retarding film layer is attached to a first surface of the light pipe. A double-layer reflection/transmission hologram is disposed on an output surface of the light pipe opposite the film layer. Light from the cold cathode fluorescent tube is injected into the light pipe, and is diffracted off of the double-layer hologram. This produces quasi-collimated s-polarized light having well-defined spectral colors that is transmitted by the hologram in an array of red, green, and blue patches of light corresponding to the clear apertures of the red, green, and blue elements of an active matrix liquid crystal display. The result is a liquid crystal display with high display brightness, reduced battery power requirements, increased battery lifetime, and high contrast over a wide viewing angle.

Abstract: An optical head apparatus consists of a semiconductor laser for radiating a light beam, a first collimator lens for collimating the light beam, a wedge-like prism for reshaping the light beam, a beam splitter for transmitting the light beam in an outgoing path and splitting the light beam in an incoming path, an objective lens for converging the light beam at an information medium in which information is stored, a plane type of hologram lens integrally formed with the objective lens for excessively correcting chromatic aberration of the objective lens to cancel out chromatic aberration of the collimator lens, a second collimator lens for converging the light beam split, a photo detector for detecting intensity of the light beam converged to obtain an information signal and servo signals, and an actuating unit for slightly moving the objective lens and the hologram lens according to the servo signals. A wavelength of the light beam is lengthened as intensity of the light beam is increased.

Abstract: A display device comprises a liquid crystal spatial light modulator (1) associated with diffractive means, such as a diffraction grating comprising grating elements (5). The diffraction grating is illuminated by a light source (6, 7) and each element is chirped and blazed so as to separate the primary colors of the illuminating light and direct them to individual light-modulating elements (R, G, B) of the modulator (1). By dispensing with conventional color filters, the efficiency of the display device is improved. Further, the focusing action of the grating elements (5) directs light to the elements of the modulator (1) so as to prevent light wastage caused by blocking of light by opaque regions of the display.

Abstract: An optical system is disclosed which focuses a polychromatic source to an extended focal pencil. The implementation makes use of two holographic optical elements (HOEs) fabricated and aligned to form a deliberate longitudinal color dispersion, but to alleviate lateral chromatic effects. Consequently, the HOE doublet focuses different wavelengths of the source to different locations along the optical axis. The strong intensity of the focused wavelengths dominate at each location, so that the overall beam has a near-diffraction-limited 1/e.sup.2 spot size and suffers only relatively weak background illumination. An alternative optical system using bulk lenses and several possible applications for the device are also described.

Abstract: An aromatic optical system that preferably includes a light source for emitting light therefrom, an achromatic optical element positioned to receive light emitted from the light source, and an optical detector positioned to receive and detect light passing through the optical element. The achromatic optical element preferably includes a substrate having opposing sides, a first computer generated hologram positioned on one side of the substrate and adapted to receive light emitted from the light source, and a second computer generated hologram positionally aligned on the opposite side of the substrate and adapted to receive light passing through the substrate from the first hologram at a predetermined location thereon.

Abstract: A display device (10) includes a display panel, such as a liquid crystal panel (12), in combination with a reflective holographic optical element (14) that redirects ambient light for illuminating the display. The light redirected by the holographic element is limited to a predetermined spectral band. Fluorescent film (16) is included for absorbing light outside the spectral band of the holographic element and re-emitting light within the spectral band to increase the light redirected by the holographic element and thus increase the apparent brightness of the display.

Abstract: A phase modulating device for spatially modulating a phase of an incident light beam is of a binary type having a plurality of rectangular protrusions on a cross section thereof. A distribution is provided to a diffraction efficiency at each point of the phase modulating device by varying a width of each protrusion.

Abstract: A vehicle light assembly includes a housing for attachment to a vehicle, a light source mounted to the housing, and a lens and/or reflector attached to the housing for controlling the distribution of light from the light source. The lens and/or reflector includes a surface with microvariations formed therein to define a holographic optical element that directs the light into a predetermined pattern for illuminating an area. The lens so formed simultaneously eliminates undesirable uneven light distribution such as glare, "spider webbing," light/dark patchiness and chromatic aberrations in and around the predetermined light pattern.

Abstract: Head-up displays on motor vehicles often have double images and interfering reflections on the windshield. To avoid these, arrangements of linear polarization filters or shutter foils are suggested, which have particularly high light transmission. Arrangements of filter plates on a combiner inside of the windshield are also advantageous.

Abstract: A flexible fiber optic delivery system for medical and industrial applications is described that can transmit high laser power densities and optical images. A parabolic-index profile of a graded-index fiber is perturbed so as to prevent strong localization of a laser beam in the fiber's recurring focal regions. This permits transmission of high laser powers without danger of fiber damage. An additional gain in carrying capacity for the system is achieved by using a wavefront perturbation system between the laser source and the graded-index fiber. Optical image transmission is achieved by using a measured perturbation to a parabolic-index profile of the graded-index fiber with a prescribed length and a wavefront reconstruction system in combination with the wavefront perturbation system. The system has an increased laser induced damage threshold and can transmit highly focused optical images.

Abstract: A method and system for fabricating a multiple holographic element. The method comprises the steps of forming a master multiple holographic element having an absorption grating pattern that produces a given index of refraction pattern across the master multiple holographic element, coating the master holographic element with a layer of a photopolymer, and directing a recording beam to and through the master holographic element and into the photopolymer layer. The absorption grating pattern of the master holographic element modulates the amplitude of the recording beam, and the modulated recording beam causes the monomers of the photopolymer to form a monomer pattern that produces the given index of refraction pattern across the photopolymer layer. The method further comprises the steps of fixing the monomers of the photopolymer layer in that monomer pattern to form thereby a copy of the multiple holographic element, and removing the photopolymer layer from the master holographic element.

Abstract: This invention concerns chromatic light separators, and is particularly intended to reduce their dimensions. A chromatic separator in accordance with the invention contains at least two selective wave length mirrors. According to one characteristic of the invention, the two selective mirrors are nested holographic mirrors. The invention is particularly suitable for three-color rear-projection type picture projectors using liquid crystal screens.

Abstract: The infra-red diffractive optical lens will remedy chromatism faults and offer excellent compactness; in addition, it does not call for a cooling device. It comprises a first convergent lens made of a material corresponding to the operational infra-red band width considered and a second convergent lens formed by a surface hologram. This hologram is obtained by accurate machining of one of the diopters of the first convergent lens according to machining data optimized by digital calculations. The first lens is preferably made of zinc sulfide. This system can operate simultaneously in the 8 to 12 microns infra-red band and the 1.06 microns laser channel.

Abstract: A narrow bandwidth bandpass filter having high transmission efficiency for the passband and excellent out-of-band attenuation employs a transmission holographic grating sandwiched between the oblique faces of a pair of right angle glass prisms. An incoming laser beam to be filtered is incident normal to one of the prism faces so as to intersect the holographic grating at about 45.degree.. The grating frequency is such as to diffract light of the transmission wavelength through substantially 90.degree. so that it exits the cube formed by the two prisms from the right angle face of the second prism. The out-of-band wavelengths of the incident beam are either transmitted unaffected through the grating or diffracted at a different angle than the light of the transmission wavelength.

Abstract: An improved method of manufacturing holographic elements for solar concentrator, which is a necessity for the future of viable low cost solar power. Utilizing extremely high relative humidity levels during the fabrication of holographic plates, exposing the holographic plate to electromagnetic radiation at particular humidity levels, and having a relative angle between recording beams during exposure makes it possible to fabricate high efficiency holographic elements that diffract over a broad bandwidth. These high efficiency, broad bandwidth holographic elements are most effective in certain solar concentrating systems.

Abstract: An artificial star is disclosed for use with an optical system (10) that has at least one optical axis (14a). The optical system includes an entrance aperture (14) through which the at least one optical axis passes and a radiation detector (22) having a radiation receiving surface. The optical system also includes an optical train having at least one optical element (16, 18, 20). The at least one optical train is disposed for receiving radiation from the entrance aperture, for directing the received radiation along the at least one optical axis, and for focussing the received radiation onto the radiation receiving surface of the radiation detector.

Abstract: A holographic center high mounted stoplight system that includes a light source for providing a nearly collimated beam, an expanding lens responsive to the nearly collimated beam for providing a diverging or converging reconstruction beam, and a stoplight hologram responsive to the expanding beam for producing stoplight illumination. Also disclosed is a holographic center high mounted stoplight system that includes a light source for providing a nearly collimated beam, a light bending hologram for providing a diffracted near collimated beam, and an expanding stoplight lens array responsive to the diffracted near collimated beam for providing non-collimated stoplight illumination.

Abstract: A holographic sight which includes a base having at least one connector for mounting the base on a small arm, and a hologram of a reticle pattern, a compact laser light source for illuminating the hologram, and a power source for the laser diode, each mounted on the base. The sight also includes an achromatizer supported in the path of the light beam for reducing shifts in the position of the reticle pattern due to variations in the wavelength of the light beam emitted from the laser diode. The sight may further include means for circularizing the generally elliptical beam emitted by the laser diode to provide a uniform illumination pattern for the hologram. A brightness adjuster and position adjuster, for varying the brightness and relative position of the reticle, respectively, may also be provided.

Abstract: An achromatic hologram optical system for converting a wave front A into a wave front B. Two holograms (H.sub.1 and H.sub.2) are provided. The length of an optical path from an equiphase front of the wave front A to an equiphase front of the wave front B is constant, and each of the two holograms has a curved surface shape.

Abstract: A lighting device includes a lighting device body, a light source placed within the lighting device body, a lens mounted in the front opening of the lighting device body, and a hologram attached to at least one specific area on the lens. At least part of light emitted from the light source is refracted by the hologram and a holographic image recorded in the hologram 16 is reproduced. A desired pattern is recorded is recorded in the form of a holographic image in the hologram. Visual presentation and light distribution characteristics, like those a conventional lighting device having a pattern of lens steps physically formed in the lens surface, can be obtained without additional optical parts.

Abstract: A compound objective lens is composed of a hologram lens for transmitting a part of incident light without any diffraction to form a beam of transmitted light and diffracting a remaining part of the incident light to form a beam of first-order diffracted light, and an objective lens for converging the transmitted light to form a first converging spot on a front surface of a thin type of first information medium and converging the diffracted light to form a second converging spot on a front surface of a thick type of second information medium. Because the hologram lens selectively functions as a concave lens for the diffracted light, a curvature of the transmitted light differs from that of the diffracted light.

Abstract: An optical displacement sensor that has a light beam polariscope located on the light path of light reflected from a target surface, and means for detecting the focal point position and transverse position of the light beam from the polariscope. The focal point position corresponds to axial displacement at the target surface, and the transverse position corresponds to inclination of the target surface, so the effect of the inclination of the surface can be compensated for by using a transverse position detection signal to adjust the light beam polariscope.

Abstract: Disclosed is a separator of polarizations comprising a Bragg grating gripped between two plates comprising input and output faces in the form of steps. The advantages of the device are that it is light and compact.

Abstract: A hologram structure for use in a holographic center high mounted stoplight system for a vehicle. The hologram structure includes a hologram layer having a plurality of holographic lenses formed therein, each holographic lens being configured to diffract light into a predetermined solid angular region.

Abstract: Scanner optics, usable for example in a bar code reader, generate a multitude of Gaussian beams derived from a common light source to produce a beam with extended working range. In the preferred embodiment, a 360 degree fan of Gaussian beams is generated by passing a laser beam through at least one diffractive element, e.g., computer generated holographic (CGH) plate, computed to perform the transformation of the illuminating beam into the desired output beam. The beam thus produced, having a small diameter over a large longitudinal distance, is useful for long range scanning.

Abstract: An optical system for a laser beam scanner, is capable of reducing the manufacturing cost by substituting a holographic optical element for a toric lens, comprising a light source for generating a laser beam, a rotary polyhedron for collimating the laser beam from the light source and focusing and reflecting the laser beam; and a compensating lens array, including a concave lens for receiving the laser beam from the rotary polyhedron and a convex lens attached with a holographic optical element, for compensating the laser beam reflected from the rotary polyhedron and scanning the compensated laser beam to a drum.

Abstract: An optical beam scanning apparatus includes one rotatable hologram which is rotatable about an axis, and at least two laser beam sources which emit laser beams. The rotatable hologram is provided with at least two hologram areas whose number corresponds to the number of the laser beam sources, so that the laser beams emitted from the respective laser beam sources are made incident upon the respective hologram areas. Each of the hologram areas is provided with a plurality of hologram facets which are concentrically arranged with respect to the axis of rotation of the rotatable hologram to emit laser beams of the same F number. The hologram areas having different numbers of hologram facets having different F numbers.

Abstract: This invention relates to the fabrication of lenses which can focus a light beam to a spot size which is smaller than that allowed by diffraction theory. A composite lens function is constructed using a strong centered lens function and several additional lens functions having different weights, different separation distances from the center, and different phases. The focused spot consists of the vector sum of these differently weighted electric fields from the separate lens functions. By varying the separation distances, the weights, and the phases of the additional lens functions, the vector sum of the electric fields from the lens functions produces a focused spot whose width is less than the diffracted limited spot size. Such composite lens functions can be produced, for example, using diffractive optics techniques or by programming the lens function onto a spatial light modulator.

Abstract: A displayer for use in a computer comprising a main body, a CRT mounted in the main body and generating an image in an electromagnetic beam, a pair of holograms for projecting the image from the CRT, the holograms mounted in the main body, and a screen for displaying the image projected by the holograms thereon, the screen mounted at a position at which the image is last projected by the holograms. The present invention provides a displayer which provides advantages in that the harmful electromagnetic waves generated from the CRT does not affect the operator by virtue of the holograms, and a screen of a desired large size is obtained at lower cost.

Abstract: The present invention concerns an optical system for the reproduction of color video images, comprising a source of illumination (1), an electro-optical modulator (3) formed from pixels associated with the colors red, green, and blue respectively, and optical collimation means (2) used to illuminate the entirety of the modulator. This system further comprises a series of wavelength-selective holographic lenses (6) making it possible to focus the light of each red, green, or blue component on the associated pixels of the modulator. Applications to videoprojectors and direct viewing.

Abstract: A hologram element receives a first and second laser beams at a first angle relative to one another. The hologram element emits the laser beams at a second angle relative to one another. The second angle is less than the first angle. The result is that laser beams from widely divergent laser sources may be directed into the same optical channel. Closely spaced beams are thereby provided for multiple beam optical data storage systems.

Abstract: A first volume hologram diffracts a portion of the beam of light as a first beam and transmits the remaining portion of the beam of light as a second beam. A second volume hologram diffracts either the first or the second beam to a desired angle and transmits the remaining beam undiffracted. Desired beam separations at desired angles may thereby be achieved for use in optical data storage systems.

Abstract: A multichip module having high density optical and electrical interconnections between integrated circuit chips. An optically transparent substrate is positioned overlying an array of integrated circuit chips mounted on a mounting substrate. The mounting substrate may include a heat sink to remove excess heat from the integrated circuit chips. The multichip module includes integrated circuit chips having optical detectors and optical transmitters to establish optical interconnections therebetween. A hologram is positioned in the optical path between the optical transmitters and the optical detectors. A planar mirror is preferably positioned opposite the hologram to direct the optical beams. The optically transparent substrate also includes an array of electrical contact pads to establish electrical connections with corresponding electrical contact pads on the underlying integrated circuit chips.

Abstract: A method of constructing holographic lenses for correction of a person's deficiencies comprises splitting a filtered laser beam onto an object under consideration and thence to a photographic film, and simultaneously conducting the other beam to the film as a reference whereby the interference patterns between the two beams form a hologram which is developed by ordinary photographic process. The hologram can be visualized by the user of the lens when the reference beam is conducted to the developed film. The lenses are individualized to correct for the particular optical deficiencies of a user by varying the focal distance.

Abstract: A viewing window is equipped with a selective attenuator for a harmful incoming laser beam. The attenuator principally employs a holographic optical element which selectively deflects the laser beam where it may be absorbed or further deflected. Ordinary light passes undeflected so that it may be processed by optical equipment or a viewer.

Abstract: This invention is a compact optical processor including a coherent light source, plural optical elements that together form a Fourier transform interferometer, and a two dimensional detector array. The light source generates a two dimensional input optical wavefront intensity modulated according to the input signal. The optical elements are formed as slab-like members with parallel input and output surfaces. These optical elements are disposed abutting in tandem. The light detecting device includes a two dimensional array of photosensitive elements generating an image signal corresponding to the processed two dimensional optical wavefront. The plural optical elements preferably include at least one acousto-optical element forming a two dimensional scanner. The plural optical elements may further includes a holographic optical element to block light undiffracted by the scanning elements.

Abstract: A hologram is used to project an image of a pattern similar to a placido upon the cornea of a subject. By viewing the reflection of the pattern in the subject's cornea, one may measure the curvature of the cornea. The use of the hologram in the keratometer system allows the pattern to be imaged at infinity, thereby minimizing any error which might otherwise result from incorrect assumptions about the cornea position.

Abstract: A system that provides a structure which makes use of a recording geometry in which no significant Seidel induced aberrations arise. The recording geometry results in a pattern recorded on a photosensitive surface, thereby creating the hologram on the scanning disc. Reconstruction of the recorded object may be made by exposing the scanning disc to substantially monochromatic light. The hologram on the scanning disc not only directs the reconstruction beam, but also focuses it. An optical element may be used during reconstruction to correct for bow and linearity, and also optimize flatness of the focal plane. Reconstruction also involves achromatization, or correction of beam placement because of mode hops or drift in laser frequency. The reconstruction comprises both pre-scan holograms and post-scan holograms. Recording of the post-scan hologram is achieved with a plurality of lenses which possess different collimating properties in the vertical and horizontal planes.

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: The visor makes it possible to obtain in binocular vision a large field of 60.degree. in the vertical plane and 120.degree. in the horizontal plane. In the case of each monocular vision channel, the visor is constituted by: an image generator such as a miniature cathode-ray tube, for example; an optical relay device; a collimation and combination optical system in which are grouped together a holographic mixing plate for transmitting the landscape channel and reflecting the image channel and a biconvex combining device formed by two holographic spherical optical elements employed on the axis for transmitting the two channels with collimation by diffraction of the image channel. A circular axial zone of zero photometric efficiency is produced in the case of each monocular vision channel and compensated by overlapping of the fields in binocular vision and, in a complementary manner, by the construction of mirror holograms providing variable index modulation.

Abstract: An image enhanced optical correlator system providing for optical preprocessing of an input image prior to processing thereof in an optical correlator. The optical preprocessing is provided to enhance the image and/or image related characteristics such that the probability of detection of prescribed targets therein in the optical correlator is increased. In the system, an input image beam is split into orthogonally polarized image inputs, processed to enhance targets therein, and then the algebraic result (addition and/or subtraction) thereof is processed through an optical correlator. Techniques are used in the feedback systems to enhance the output plane correlation signal detection by an adjustment in phase, spatial frequency filtering and/or threshold setting optimization.

Abstract: A hologram that diffracts playback illumination over a wide angular range made pursuant to a technique that includes the steps of first exposing a volume hologram recording medium to record a first image which upon playback will diffract light over a first angular coverage, and then exposing the volume hologram recording medium to record a second image which upon playback will diffract light over a second angular coverage.

Abstract: A holographic member for a helmet visor comprising a first holographic layer having planes of diffraction oriented in a first direction in a given local area is disclosed. A second holographic layer disposed over said first holographic layer has planes of diffraction oriented in said local area in the opposite direction. The first holographic layer is transferred from a slanted planar holographic mirror. The second holographic layer comprises the holographic analog of an oppositely slanted transferred planar mirror. The slant and the opposite slant have substantially the same magnitude of slant but opposite orientation, providing for diffractive ghost compensation. A third holographic layer, unslanted, is transferred from an unslanted planar holographic mirror. The three holographic layers provide practical total eye coverage with minimum diffractive unwanted ghosts.

Abstract: A holographic stoplight for a vehicle including a stoplight hologram, a source of playback illumination, and a transparent prism for supporting the stoplight hologram and for guiding the playback illumination to the stoplight hologram. The prism with the stoplight hologram is mounted in front of the rear window of a vehicle with the light source beneath the surface of the rear panel that is adjacent the rear window.

Abstract: An optical interconnect system facilitates the simultaneous bi-directional transfer of data between facing integrated circuits. The laser simultaneously emits two oppositely directed continuous beams of light. Holographic elements placed in the paths of the beams of light split each into multiple light beams, creating independent optical communication channels. Reflective modulators are positioned on integrated circuits in the path of each communication channel to selectively reflect the respective light beams. The light beams are modulated in response to data input to the reflective modulators from the integrated circuits. Opto-electronic receivers are positioned on the integrated circuits in the path of the light beams reflected by the reflective modulators. Holographic elements focus each reflected light beams onto an opto-electronic receiver. Data is extracted from the light beams by the opto-electronic receivers and output to the integrated circuits.

Abstract: An optical interconnection arrangement having a high degree of connectivity and bandwidth is obtained by a non-collinear arrangement of lenses. In a preferred embodiment, the optical system comprises a first pupil lens, a second pupil lens and an array of fanout lenslets wherein the optical axes of the first and second pupil lenses are collinear. The first and second pupil lenses form an afocal system with the array of fanout lenslets situated between and at the focal planes of the first and second pupil lenses. Light beams from arrays of light emitting devices are collimated by input probe lenses that have their optical axes non-collinear with the optical axis of the first lens. The first pupil lens forms a coincident pattern of the arrays of light emitting devices. Additionally, the array of fanout lenslets fans out exiting beamlets comprising the coincident pattern such that each exiting beamlet substantially fills the aperture of the second pupil lens.

Abstract: The invention provides a non-linear projection system, which includes a variable acuity non-linear holographic optical element (HOE), and an apparatus for creating the HOE. The projection system comprises a computer, a light valve which projects images generated by the computer, a lens train for focusing the images projected by the light valve, an HOE for the non-linear refraction of the focused images and a hemispherical viewing screen. The system additionally provides means for maintaining the center of the projected images in alignment with center of the field of view of an observer. The variation of the pixel size and spacing created by the system matches the variation of the human visual acuity of the observer permitting a realistic view to be presented while requiring a minimum of computer data to be generated and projected. The apparatus for creating the HOE utilizes a laser beam, three lens trains and a holographic recording medium.

Abstract: A transmission holographic element (1) composed of a first reflection holographic optical element (2) and a second reflection holographic optical element (3). Reflection holographic optical elements (2,3) are adhesively mated such that the distance separating the two elements is no more than a few wavelengths of the incident light beam (9). The incident light beam (9) passes through first element (2) and is reflected off of the second element (3) which reflects the light beam back towards first element (2) which again reflects the light beam through the second optical element (3). In this manner, two discrete reflection holographic elements (2,3) behave as a single transmission holographic element.