Abstract: An opaque document scanner in which a moving hologram generates a locus of points from a stationary light beam on an opaque document and the same hologram or a similar one mounted for conjoint movement collects light energy reflected from the document at each point and focuses this energy onto a stationary detector to provide electrical signals corresponding to the information scanned on the document.

Abstract: Coherent optical correlation is applied to an article having circular features as well as noncircular features. A spatial filter is constructed for a typical part with the noncircular features masked out. The filter is placed in the transform plane of the optical correlation system so that the system will produce correlation signals indicating the presence, the coordinate position and angular orientation of the part within the field of view of the system.

Abstract: The holographic recording system comprises a pair of aligned first and second Fourier transforming lenses, a holographic beam splitter having a series of random phase illumination holograms at a front focal plane of the first lens and arranged to move in a given direction to successively receive a light beam for deffracting it into a zero-order diffracted beam and a first-order diffracted array of sampled, phase shifted beams, and a mask having a first and second apertures disposed at the Fourier transform plane of the first lens. A page composer having electrooptical transducers is positioned in the second aperture to receive the first-order diffracted array of beams to spatially optically modulate the incident beams in accordance with one of successive groups of binary signals.

Abstract: Each one of three filters, corresponding to different primary subtractive colors of a color picture, is embossed as a relief pattern on the same side of a plastic film within a separate one of any three of four side-by-side regions into which the film is divided. This permits the film to be thrice-folded to both (1) superimpose the three filters substantially in registration with each other and (2) place the embossed side of the film within the interior of the thrice-folded film where said filters are protected.

Abstract: The present invention relates to holographic lenses.The wide field holographic lens in accordance with the invention is obtained by the superimposition of interference networks recorded within the volume of a thick material. These networks constitute a corresponding number of thick elementary holographic lenses, each of which satisfactorily covers a specific region of the field; the invention likewise describes a device for constructing said wide field holographic lens.

Abstract: A flat disk contains a number of holograms made from the interference of a plane wavefront with spherical wavefront modified by a first cylindrical lens. The disk is rotated so that a plane reconstruction wavefront sweeps across the holograms. The resulting reconstructed wavefront is passed through a second cylindrical lens, resulting in a focussed point sweeping across an object surface in one or more substantially straight lines.

Abstract: A helium cadmium laser generates an output beam of radiation which is coupled through a spatial filter and beam expander to a beam splitter which in turn provides two enlarged beams of coherent radiation of approximately equal power. Two highly reflective mirrors are used to direct the two beams such that the two beams interfere and create the usual interference pattern in a positive photoresist layer covering an optical substrate. A thin sheet of high index glass is held by two blocks of quartz in a position adjacent to the photoresist layer and oriented such that a part of each beam of coherent radiation is caused to pass through the high index glass before interfering with the other beam on the photoresist layer. As a result, a grating having a quarter wavelength step or discontinuity in the middle of the grating is fabricated in the photoresist. The photoresist pattern is then transferred to the optical waveguide by ion-beam milling.

Abstract: An optical low-pass filter in the form of a rectangular wave phase grating including at least two sets of parallel phase retardation laminae, the laminae in each set being at an angle to the laminae of the other set. The optical filter is disposed in an optical system provided with a color-encoding filter, such as a single tube color television camera, and the high frequency components of an image on the color-encoding filter are attenuated below a predetermined level. The degree of blur, which is larger than the value calculated from the grating period of the color-encoding filter, is effected by a first set of laminae and beats appearing in the image defocused on the color-encoding filter due to the laminae is attenuated by another set or the other set of laminae.

Abstract: A space defined between two face-to-face panes of a window is adapted to be selectively flooded with a colored liquid in order to reduce the transmission of heat and/or light through the window. The window is characterized by the provision of a supply manifold located between the panes and by the manner of delivering liquid to the manifold and into the space to insure against unequal pressures and thereby eliminate the danger of the panes being broken.

Abstract: Apparatus for piecewise generation of grating-like patterns in photoresponsive material with a coherent the class which splits the coherent beam into two component beams. The two component beams intersect forming a parallel plane interference pattern on a section of the photoresponsive material. An arrangement which translates the beam parallel to itself forms the interference pattern in registration with the previously generated pattern on a different section of the photoresponsive material.

Abstract: A holographic polynomial computer in which powers and products of the input variables are obtained by repeated diffraction at the input hologram. The information bearing beams are split, redirected, and combined by thick holograms acting as mirrors. Many real, complex or Boolean polynomials in many variables are evaluated simultaneously in parallel. Input variables and coefficients are represented by diffraction efficiencies of holograms. Final and intermediate results are represented by amplitudes of coherent optical beams. Multiplication is performed by diffracting a beam from a hologram and addition is performed by combining beams. The computer may be controlled to compute alternate functions of the input data by supplying alternate optical input beams.

Abstract: A two dimensional optical phase grating filter is provided that is capable of limiting the transmittance of spacial frequency signals in one or more scan directions. The two dimensional grating of the present invention can be utilized as an optical low pass filter to improve image resolution in a color video system. In the color video system, the two dimensional grating filter could be designed to optically complement a dichroic stripe filter to prevent the introduction of spurious signals by any interference of luminance and chrominance signals. The design parameters of the present invention provide an improved cut-off characteristic with grating widths larger than one-half of the filter period. The two dimensional phase grating filter of the present invention can also be utilized in other optical systems, such as an automatic focusing system, where it is desired to pass only a certain spacial frequency as a monitored signal for the automatic adjustment of the focus of the optical system.

Abstract: A linear optical processing system for copying graphic images which includes a spatial filter in the form of a Fourier transform hologram together with a lens for processing incoherent electromagnetic radiation. The system provides a given real, substantially-uniform low-pass two-dimensional optical transfer function for spatially filtering incoherent radiation within a range of spatial frequencies 0<.omega.<.OMEGA.. The spatial filter is made by forming a mask representing a point spread function which is the inverse transform of the desired optical transfer function, and employing the mask in a coherent system to produce as the filter a Fourier transform hologram of the mask.

Abstract: A linear optical processing system in which a spatial filter in the form of a Fourier transform hologram is included with a lens for processing incoherent electromagnetic radiation. Such a system provides a given real, two-dimensional transfer function for spatially filtering incoherent radiation within a range of spatial frequencies 0 .ltoreq..omega..ltoreq..OMEGA.. The filter is made by forming a mask of a graph of a point spread function which is the inverse transform of the desired transfer function, and employing the mask in a coherent system to produce a Fourier transform hologram of the mask. Spatial filters are designed for providing the resultant systems with various transfer functions, including (a) a directional response for passing substantially higher spatial frequency components in a first direction than are passed in a second direction; (b) a selective attenuator response; (c) a notch filter response; (d) a correctional filter response; and (e) a linear minimum mean square error response.

Abstract: A method of layer-wise reproduction of three-dimensional images by way of a number of simultaneously recorded, encoded superposition images of different image planes. The object is irradiated from different directions. Simultaneous-superposition images of the object are recorded in encoded form, by means of a large number of m sources, from different directions in a number of n planes which are situated one below the other. The decoding of these images for the layer-wise reproduction of the three-dimensional object is effected so that for each individual layer each of the n simultaneous-superposition images, whose scale has been adapted relative to each other, is simultaneously or consecutively shifted and summed on a single recording medium a number of times which corresponds to the number of m sources during the recording of the object.

Abstract: An optical holographic memory device wherein a plurality of hologram plates, each plate comprising an array of sub-holograms, are arranged in a predetermined horizontally registered relation to one another, the amount of information recorded on the plates thereby not being restricted by the light deflecting device utilized to read a selected sub-hologram.

Abstract: An optical parallel computing system in which modes of a multi-mode laser are coupled holographically. The bistable state of oscillation of individual modes is controlled by a saturable absorber placed in a part of the laser cavity which permits the control of each mode separately. A mode oscillates on the condition that the amount of optical energy coupled into that mode exceeds a threshold value. The amount of coupling between pairs of modes is dependent on the input data which is presented as a hologram. The output is read from the selection of modes which oscillate. The holographic part of the data processing system is a coherent optical computer which evaluates linear or nonlinear polynomial operators on the input data and can inject a proportional amount of energy into a mode, which then oscillates if the value of the operator exceeds a threshold. Holograms in the coherent optical computer store both data and program for the computing system.

Abstract: A color hologram is recorded on a holographic recording material sequentially by use of different color coherent light beams with a stripe filter placed on the recording material and moved by a length equal to the width of the transparent stripes of the filter for each different color laser beam. The color holographic image recorded is therefore composed of stripes of different color component arranged side by side in a fixed order. The color holographic image is reconstructed by exposing the hologram simultaneously to different color reference light beams through stripe filters inserted in the respective reference light beams.

Abstract: A plurality of multicolored transparencies or pictures having different parallactic views of a scene are aligned with each other and illuminated by red, green, and blue coherent beams. The resulting images are focused on a holographic recording medium through an aperture elongated along the direction of the alignment of the pictures. A hologram is recorded by red, green, and blue coherent reference beams directed at the recording medium. The images are reconstructed with a white reconstructing beam or a reconstructing beam composed of quasi-monochromatic colors and observed through an aperture corresponding to the first aperture and arranged in the same position. The hologram has recorded thereon a focused image hologram of the pictures and a Fresnel hologram of the aperture. The reconstructed image may be expanded by a screen which is directive in one direction, i.e. retroreflective horizontally, and dispersive in another direction, i.e. vertically dispersive.

Abstract: A method of forming a minimum mean-square error linear filter photographically is disclosed.The optimum filter may be obtained photographically. In one form, a first photographic negative of a monolayer of cells having a high percentage of cells of the given type is made at the focal plane of a transforming lens mounted so as to collect the light scattered by the monolayer; and, developed for a gamma of unity. Thereafter, a second photographic negative is made at the same focal plane of a monolayer of cells containing a normal percentage of cells of the given type using the first negative as a filter. The second negative is developed for a gamma of two. The resulting photographic plate is a realization of the desired optimum (minimum mean-square error linear) filter.