Abstract: A method of generating a holographic diffraction pattern and a holographic lithography system. The method involves defining at least one geometrical shape; generating at least one line segment to represent the at least one geometrical shape; calculating a line diffraction pattern on a hologram plane, including calculating the Fresnel diffraction equation for an impulse representing the at least one line segment with a line width control term and a line length control term; and adding vectorially, where there are two or more line segments, the line diffraction patterns to form the holographic diffraction pattern. The method and system enables holographic masks to be generated without creating a physical object to record. The required shapes or patterns are defined in terms of a three-dimensional coordinate space and a holographic pattern is generated at a defined distance from the shapes in the coordinate space.

Abstract: According to the present invention, a plurality of video image data are converted into individual spatial frequency information using Fourier transformation. The individual spatial frequency information is provided to a plurality of information display unit corresponding to the individual spatial frequency information. The spatial frequency information corresponding to the plurality of video image data is displayed on the plurality of information display unit, light is irradiated onto the plurality of information display unit using a plurality of light sources corresponding to the plurality of information display unit. The spatial frequency information that is displayed by the plurality of information display unit is projected by using diffraction light, and a plurality of video images are synthesized on projection surfaces.

Abstract: The present invention relates to an apparatus for writing to optical storage media capable of performing pre-exposure and/or curing of a photo-sensitive material for optical data storage, in particular for holographic data storage. The apparatus has a first light source for emitting a first light beam, a second light source for emitting a second light beam, and a spatial light modulator, which is switchable between at least two states for spatially modulating at least a part of the first light beam, and which is arranged such that in a first state it directs the first light beam towards an optical storage medium, and that in a second state it directs the second light beam towards the optical storage medium.

Abstract: Methods create images viewable under different selected angels on optical storage devices and other photosensitive surfaces and optical storage devices with super-imposed images. Generally, a photosensitive surface is exposed with multiple diffraction patterns creating super-imposed images. These diffraction patterns create super-imposed images on the photosensitive surfaces, which can be read by either a human or a computer.

Abstract: A hologram media reading apparatus including a reference light source, a stop with gray level aperture, and an optical sensor is provided. The reference light source is disposed on one side of a hologram medium, and capable of emitting a reference light beam. The reference light beam is transmitted to the hologram medium. The stop with gray level aperture and the reference light source are disposed on the same side or opposite sides of the hologram medium. The stop with gray level aperture has a light transmissive region, an opaque region, and a transmittance gradually varying region. The opaque region surrounds the light transmissive region. The transmittance gradually varying region surrounds the light transmissive region. A part of the reference beam from the hologram medium passes through the stop with gray level aperture and is transmitted to the optical sensor.

Abstract: In a three-dimensional video display apparatus, accommodation and convergence among physiological characteristics of eyes are abandoned, thereby resulting in generation of unnatural three-dimensional video. For example, even when eyes are moved, a screen is not changed, and a cardboard effect and/or a miniature garden effect may be caused, so that the eyes may be greatly fatigued. Light emission sources 1R, 1G, and 1I, holograms 3R, 3G, and 3I, and a transparent display component 4 are provided, and a plurality of reflectors 6 are formed in the display component 4 so as to be positioned at intersections in a space lattice.

Abstract: A hologram reading apparatus includes: a unit for holding a hologram recording medium in which data page is recorded by irradiating as a single beam both reference light and signal light modulated by a spatial light modulator including a first pixel area for modulating the reference light and a second pixel area for modulating the signal light, a direction of an arrangement period of pixels in the first pixel area being different from that in the second pixel area; a Fourier transform lens subjecting reproduction light to a Fourier transformation; a filter disposed shielding the reference light at a first spatial frequency band and transmitting the signal light at a second spatial frequency band; and a unit for receiving the reproduction light and reading the data page modulated to the signal light included in the reproduction light.

Abstract: Various embodiments include interferometric optical modulators comprising a substrate layer having a thickness between about 0.1 mm to about 0.45 mm thick and a method for manufacturing the same. The interferometric modulator can be integrated together with a diffuser in a display device. The thin substrate permits use of a thicker diffuser. The thinner substrate may increase resolution and reduce overall thickness of the interferometric modulator. The thicker diffuser may provide increased diffusion and durability.

Abstract: A method of creating a substrate containing multiple holographic images. The method includes dividing the substrate into a plurality of equally sized print surfaces and placing a holographic image on each of the print surfaces. Wherein the holographic image is placed at substantially the same location on each of the print surfaces.

Abstract: A computer-generated hologram that is capable of reconstructing a full-color image and achieving a high resolution is provided. A recording plane of the hologram is divided by a multiplicity of parallel sections in the horizontal direction to define a multiplicity of areas. Amplitude information and phase information corresponding to different wavelengths which vary periodically in a direction traversing the multiplicity of areas, is recorded in the recording medium. Information about the same portion of the original image is recorded in individual points belonging to the same area, and information about another corresponding portion of the original image is recorded in individual points belonging to another area.

Abstract: Systems and methods for shearless digital hologram acquisition, including an apparatus incorporating an illumination source configured to produce a first beam of light, which is then split by a beamsplitter into a reference beam and an object illumination beam. The reference beam is directed onto a phase-shaping optical element which imparts a phase shift to the reference beam and returns the phase-shifted reference beam on itself to the beamsplitter. The object illumination beam is directed onto an object, and a portion of the beam is reflected back to the beamsplitter, which combines the phase-shifted reference beam and object illumination beam substantially coaxially. The combined beams are passed through a focusing lens which focuses them at a focal plane. A digital recorder is positioned at the focal plane to record the spatially heterodyne hologram formed by the focused phase-shifted reference beam and reflected object illumination beam.

Abstract: A holographic recording medium including a recording layer on a substrate, which records data information in a light interference pattern is provided. In the holographic recording medium, information on a thermal expansion characteristic of a recording material contained in the recording layer and/or information on temperature dependency of the refractive index of the recording material are recorded within the holographic recording medium in advance.

Abstract: An apparatus for reading a hologram, in particular a computer-generated hologram, that includes a radiation source for irradiation of the hologram with a read beam composed of electromagnetic radiation, and an outlet opening for receiving an image that is produced from the hologram. The apparatus may allow both greater variability and greater convenience in use with a simple design. The apparatus further includes optics having at least two lenses in which a focal point of the first lens and a focal point of the second lens are each arranged essentially on one plane, and in which the hologram is arranged in front of the second lens as viewed along the beam direction.

Abstract: A method is disclosed to store and retrieve information using holographic data storage media. The method provides original data, generates a first image of that original data, and encodes that first image in a holographic data storage medium at a first storage location. The method then generates a second image of the original data, where the second image differs from the first image, and encodes the second image in a holographic data storage medium at a second storage location, where the second storage location differs from the first storage location.

Abstract: An optical information recording device, a reproduction device, and a method enabling include a first spatial light modulator I for generating information light by spatially modulating light from a light source 143 by a plurality of pixels and a second spatial light modulator R for generating reference light by spatially modulating light from a light source by a plurality of pixels. The area I of the information light and the area R of the reference light on the entrance pupil surface of an objective lens 111 are formed such that one area surrounds the other area. The reference light is spatially modulated by the second spatial light modulator R such that interference is not easily generated between the reference lights in the information recording layer 3.

Abstract: For displaying a color image by recombination of several single color images, parasitic noise like speckles due to scattering within the system, in particular when laser light is involved, with the invention a significant improvement with a low number of parts can be realized by use of a color wheel that comprises in radially divided zones refractive elements for redirecting light beams incoming at different impinging angles and redistributing elements, e.g. a hologram, that provide for a defined output beam in an optical axis. The sequence of the individual light processing zones on the color wheel are synchronized with respective laser sources. The invention combines the functionality of plural elements, reduces speckles and avoids losses.

Abstract: An object is to prevent lowering of a dynamic range of a hologram recording medium without lowering an average data transfer rate, and to provide stabilized recording sensitivity. A scheduler determines a recording interval time from the point of time when light is irradiated to record a certain hologram of holograms to be multiplex-recorded to the point of time when light is irradiated to record a succeeding hologram in such a manner that at least parts of the holograms are recorded one over the other in a certain recording area. A recording interval time controller controls a light source to irradiate the light depending on the recording interval time determined by the scheduler.

Abstract: An object of the present invention is to display a highly reproducible three-dimensional image in response to changes in the viewer's position and to easily realize the miniaturization of the system. The three-dimensional image projector 1 includes a projection image forming disc 4 in which a hologram recording medium 9 is formed along a disc-shaped glass substrate 8a, and which projects image light having directivity by causing the image light to fall incident on the hologram recording medium 9, and a rotational drive unit 3 for rotationally driving the projection image forming disc 4 along a surface of the glass substrate 8a with the center point C1 on the surface as a rotation center. The projection image forming disc 4 is preliminarily recorded with a hologram 11 by causing two laser beams L2, L3 as reference light and object light to simultaneously fall incident on the hologram recording medium 9.

Abstract: A security element, preferably for documents of value, which at least has one area with a diffraction structure, which under specific viewing conditions reconstructs a diffractive image. This area has subareas, which do not take part in the reconstruction of the diffractive image, and which represent a recognizable information. Essential is that the information represented by the subareas is recognizable mainly only under the viewing conditions, under which the diffractive image can be perceived.

Abstract: A multicolor hologram (e.g., a two-color hologram) is replicated (copied) into a photosensitive layer by masking to produce a copy (replicate) of the hologram in a manner such that the copy is an accurate and true replication of the hologram (e.g., master hologram), and the copy is characterized to possess a high brightness level and color fidelity comparable to that of the multicolor hologram that was replicated. Both flood and scan modes can be employed in the replication.

Abstract: A holographic multiplex recording method which can keep a recording data rate constant and equalize nonuniformity in recording due to vibrations or the like, and a holographic recording apparatus and a holographic recording medium, which employ the method. In a process of multiplex-recording information, the time of exposure to a laser beam per data page is kept constant, and the laser output power of the laser beam is increased in accordance with a decrease in recording sensitivity of the holographic recording medium.

Abstract: The invention comprises a pattern generation unit (20), a programmable lighting means and a holographic screen (28) that together make a holographic volumetric display. The holographic screen contains a pre-recorded set of volume elements or voxels (32) in three dimensional space outside the plane of the holographic screen. The holographic screen comprises a series of sub-holograms where each sub-hologram is associated with a voxel such that the voxel may be reconstructed when the sub-hologram is illuminated. A sub-hologram is a sampled hologram of a voxel and sub-holograms are spatially multiplexed and interleaved across the surface of the holographic screen. The programmable lighting means may be provided by a colour digital projected unit (28) and the pattern generation unit which can illuminate any number of sub-holograms on the holographic screen. In this way, a volumetric display with holographic voxels can be made.

Abstract: A method and apparatus for scanning an input beam of light in a two dimensional pattern; splitting the scanned input beam of light into two output beams of light, each one of the two output beams of light passing along a different path to a common region in a recording medium, such region scanning the recording medium during the scanning of the input beam of light to produce a diffraction grating in the recording medium by interference between the two output beams of light.

Abstract: A holographic storage and reproduction system and method with a servo are provided, wherein a servo mechanism is provided, such that the holographic interferogram is continuously stored in the holographic recording medium. When a reproduced signal is to be obtained, it can be retrieved quickly and accurately through the servo mechanism. Also, the intensity distribution of the reference light reflected by the holographic recording medium can be monitored and controlled, such that the relative distance and oblique angle between the storage and reproduction system and the holographic recording medium are analyzed and adjusted.

Abstract: At the time of varying the angle of a scan mirror for varying the angle of incidence of a reference beam on a hologram recording material, the angle of a slit is also varied in conjunction, whereby the beam diameter of the reference beam is varied by the slit so that the irradiation range on the hologram recording material will be constant without being varied according to the variation in the incidence angle of the reference beam. This ensures that the area of irradiation of the hologram recording material with the reference beam can always be kept constant, even when the incidence angle of the reference beam is varied at the time of recording holograms by the angle multiplex recording system.

Abstract: A method is provided for controlling an at least partly automatically implementable driving maneuver by which a motor vehicle can be moved from an actual position into a desired position. In the environment of the motor vehicle, a virtual target object is generated in a target position for the motor vehicle in the environment of the motor vehicle by projection using projection devices provided on the motor vehicle. As a function of operating actions of an operator of the motor vehicle, the target position is changed, whereby also the target object is displaced in the environment of the motor vehicle. And, by way of a selecting action of the operator, the changed target position is selected and utilized as the desired position of the driving maneuver.

Abstract: The present invention relates to a holographic storage system, and more specifically to a holographic storage system using a phase spatial light modulator. According to the invention a holographic storage system with a phase SLM for imprinting a 2-dimensional phase data pattern onto an object beam includes a common path interferometer for converting the phase data pattern of the object beam into an intensity data pattern.

Abstract: Methods create images viewable under different selected angles on optical storage devices and other photosensitive surfaces and optical storage devices with super-imposed images. Generally, a photosensitive surface is exposed with multiple diffraction patterns creating super-imposed images. These diffraction patterns create super-imposed images on the photosensitive surfaces, which can be read by either a human or a computer.

Abstract: A data reading method used in a reading device for reading a holographic storage medium is provided. The holographic storage medium has several data areas. Each data area has several data pages, and each data page forms a data image that has at least one reserved block pattern on the reading device. The reserved block pattern of the data image corresponding to a first data page is searched within a first searching region to obtain a first pattern position. The reserved block pattern of the data image corresponding to a second data page is searched within a second searching region to obtain a second pattern position. A third searching position is then determined according to the first and second pattern positions. The reserved block pattern of the data image corresponding to a third data page is searched within a third searching region whose center is at the third searching position.

Abstract: A method of and apparatus for recording/reproducing data on/from a holographic storage medium. The method of recording data on a holographic storage medium in which holograms containing data by interference between a signal light and a reference light are recorded in pages includes modulating additional information including information about a page so as to keep the rate of 0s or 1s in binarized data of the additional information constant and recording the page having the modulated additional information added thereto on the holographic storage medium.

Abstract: A collinear volume holographic optical storage system records a plurality pages of holographic data on the storage material, where the intensity distribution of the saved recorded holographic data of each page is in a “+” format. It is possible to incur the inter-page cross talk between two adjacent pages of holographic data along the storage track or between two adjacent storage tracks. An rotation angle between the direction of the distribution of the volume grating and the direction of the storage track can be used to increase the descendent of data storage intensity along storage track, so the effect of the inter-page cross talk is decreased; or the distance between reading centers of two pages of holographic data is shorten to increase the storage density of the storage material.

Abstract: The present invention relates to an apparatus for reading from and/or writing to holographic storage media, and more specifically to an apparatus for reading from and/or writing to holographic storage media having an apodization filter. According to the invention, an apparatus for reading from and/or writing to a holographic storage medium, with a collinear split aperture arrangement of a reference beam and an object beam or a reconstructed object beam, includes an apodization filter for the reference beam.

Abstract: A reflective or transmissive hologram may be used to extract light from a waveguide. The hologram may be formed by separately exposing each of a plurality of areas of a holographic medium with object beams and/or reference beams having attributes (e.g., illumination angles) that vary randomly or pseudorandomly over the entire hologram. The areas may be contiguous (e.g., in a tiled pattern) or overlapping. In some embodiments, the spacing and/or orientation of the diffraction gratings may vary from area to area. For example, the spacing and/or orientation of the diffraction gratings may vary randomly or pseudorandomly from area to area. Some parts of the hologram may intentionally be made relatively more or relatively less efficient at extracting light from the waveguide.

Abstract: Described herein is a new holographic polymer dispersed liquid crystal (HPDLC) medium with broadband reflective properties, and a new technique for fabrication of broadband HPDLC mediums. The new technique involves dynamic variation of the holography setup during HPDLC formation, enabling the broadening of the HPDLC medium's wavelength response. Dynamic variation of the holography setup may include the rotation and/or translation of one or more motorized stages, allowing for time and spatial, or angular, multiplexing through variation of the incident angles of one or more laser beams on a pre-polymer mixture during manufacture. An HPDLC medium manufactured using these techniques exhibits improved optical response by reflecting a broadband spectrum of wavelengths. A new broadband holographic polymer dispersed liquid crystal thin film polymeric mirror stack with electrically-switchable beam steering capability is disclosed.

Abstract: A monocular holographic storage device or system to provide for compact recording and/or reading of data pages in a holographic storage medium. Also provided are methods for carrying out such data storage and/or data recovery using a monocular holographic storage device or system. Further provided are articles including holographic storage media for recording or for reading recorded data using such devices or systems.

Abstract: A process for recording information on and reproducing information from a reflection-type holographic information recording medium, having a reflecting layer. Recording includes (i) branching a light beam from a light source into a first branched light beam and a second branched light beam, (ii) forming an information light beam from the first branched light beam by modulation with a spatial light modulation element, and (iii) recording the information by forming an interference fringe by projecting the second branched light beam as a recording reference light beam together with the information light beam onto the recording medium. Reproducing includes projecting a light beam from the light source as a reproducing reference light beam onto the interference fringe. An angle of incidence of the recording reference light beam and an angle of incidence of the reproducing reference light beam into the interference fringe are one hundred eighty degrees from one another.

Abstract: A method to evaluate a holographic data storage medium, wherein the holographic data storage medium is evaluated by a manufacturer. In certain embodiments, the holographic data storage medium is evaluated by a customer prior to encoding customer information into the storage medium. In certain embodiments, the holographic data storage medium is evaluated by a customer after encoding customer information therein.

Abstract: There is provided a hologram recording method, including generating a signal light which is spatially modulated such that digital data is represented by an image of intensity distribution, irradiating the signal light on an optical recording medium after a Fourier transformation of the signal light such that a zero-order component of the signal light comes into focus at a point removed from the optical recording medium, forming a diffraction grating in the optical recording medium by interference between the zero-order component of the signal light and a high-order component thereof, and recording digital data represented by the signal light as a hologram.

Abstract: The nature of a volume hologram limits its use in security and sensing applications. Accordingly, a volume hologram segregated into a first and second region recording a first and second image, respectively, and wherein the second region is responsive to stimulus while the first region is protected physically from stimulus is provided. Also provided is a volume hologram with a functional cover disposed thereon to regulate how the volume hologram interacts with the stimulus when in the presence of stimulus. A volume hologram with a removable cover disposed thereon to permit a first recorded image to be viewed, to protect the volume hologram from physical damage, to prevent the volume hologram from interacting with the stimulus, and to be removed, thereby permitting the volume hologram to interact with the stimulus is provided as well. In these ways, the usability of volume holograms in security and sensing applications is increased.

Abstract: A method is disclosed to store information in a holographic data storage medium. The method provides a hologram comprising an alignment pattern, and disposes that hologram into a holographic data storage medium during manufacture.

Abstract: A method to store information in a holographic data storage medium, wherein the method supplies a holographic data storage medium comprising an encoded focusing hologram and one or more encoded data holograms. The method disposes the holographic data storage medium in a holographic data storage system such that a moveable imaging lens is disposed at an (i)th position. The method illuminates the encoded focusing hologram to generate an (i)th reconstructed focusing image, projects that (i)th reconstructed focusing image through the moveable imaging lens, and onto said optical detector. The method then calculates an (i)th measured focusing metric, and determines if the (i)th measured focusing metric is greater than or equal to the threshold focusing metric. If the (i)th measured focusing metric is greater than or equal to the threshold focusing metric, then the method decodes the one or more encoded data holograms.

Abstract: A method is disclosed to determine an optimal optical detector orientation to decode information encoded holographically. The method supplies a matched filter, an orientation image, a holographic data storage medium encoded with the orientation image, and an optical detector comprising a moveable input screen comprising a plurality of detector elements. The method positions the input screen in a plurality of input screen orientations and calculates a correlation factor for each of the input screen orientations. The method determines an optimal optical detector orientation using the plurality of correlation factors.

Abstract: A hologram reproducing device includes a splitter for splitting a reference beam, during reproduction, into a main beam and sub-beams forming incidence directions spatially shifted from the main beam. The hologram reproducing device also includes: an incidence direction variable irradiator for changing the incidence directions of the main beam and the sub-beams; a servo beam detector for detecting a portion of the reproduction beam generated in accordance with the sub-beams; and a beam receiving unit for receiving the main portion of the reproduction beam generated in accordance with the main beam. A reproducer reproduces an image obtained by the beam receiving unit when the main beam coincides with the incidence direction at which the received light of the beam receiving unit becomes equal to or greater than a prescribed level, with the intensity of the reference beam kept uniform, on the basis of the servo beam detection results.

Abstract: A method of making a product containing a hologram which has at least two replay colours when viewed at a given angle, the method comprising the steps of: (i) recording holographic elements at each of at least two different angles in a master; and (ii) copying the master. The principle of the system is demonstrated by creating 2 surface relief objects, A and B on top of a mirror background. When a holographic recording medium is placed on top of this surface relief object and then illuminated with a coherent laser beam, interference patterns are recorded and developed within the polymer which describe the relief patterns (C-E). When the hologram is illuminated with white light and viewed normal to the hologram surface, the separation between the fringes relative to the viewing angle then becomes da and dc for surface relief objects A and B respectively (Figures C and E) and remains the same for the mirror (Figure D).

Abstract: A hologram recorder includes a signal beam irradiator to irradiate a signal beam, which is optically modulated in accordance with information to be recorded, to a recording medium at a predetermined incident angle. The hologram recorder also includes a recording prism provided with surfaces including an incident surface, a reflective surface and an emission surface for light so that a recording reference beam is guided to the recording medium by way of these surfaces. A pivot mechanism of the hologram recorder causes the recording prism to pivot above the recording medium for changing the incident angle of the recording reference beam at the recording medium, with the recording reference beam kept to overlap the signal beam.

Abstract: A multilayer holographic recording medium that improves recording density and data transfer rates. The multilayer holographic recording medium, from which information is reproduced by a multilayer holographic memory reproducing apparatus, includes a plurality of deposited holographic recording layers. During recording, a reference beam is common to those holographic recording layers and an incident angle of an object beam is modulated for each holographic recording layer. During reproduction, a laser beam for reproduction having the same condition as that of the reference beam used for recording is projected thereonto, so that diffraction beams are simultaneously generated in the respective holographic recording layers to directions that are the same as incident directions of the object beam used for recording.

Abstract: To provide a two-dimensional modulation method for hologram recording which is capable of preventing degradation of reconstructing performance when positional shift occurs and which enables information to be stably recorded or reproduced. The hologram recording carrier employs the two-dimensional modulation method for hologram recording for generating coherent light containing therein page data through a spatial light modulator having a plurality of pixels two-dimensionally arranged therein, in which the pixels of the spatial light modulator are partitioned into a plurality of blocks consisting of m pixels adjacent to each other (where m=an integral number), and a boundary portion which has a width having at least the width of one pixel of the spatial light modulator or of one pixel of an image detecting sensor used to reproduce the recorded page data and the distance between the adjacent pixels in each of the blocks, and each of which shields light is provided between the adjacent blocks.

Abstract: A hologram apparatus which comprises a light generating unit that generates coherent reference light and coherent signal light modulated according to information to be recorded; an interference optical system that irradiates the signal light and the reference light toward the record medium to intersect therein, thus forming a diffraction grating inside the record medium by an optical interference pattern; and a photodetector that detects reproduced light. The hologram apparatus further comprises a second interference optical system that irradiates second signal light and second reference light to intersect inside the record medium, wherein the second signal light and the second reference light are placed in the plane of incidence including the signal light and the reference light of the interference optical system so as to be opposite to the signal light and the reference light with the record medium sandwiched in between; and a second photodetector that detects reproduced light.

Abstract: An apparatus for simulating a solid fuel fire comprises a sheet, preferably in the form of a holographic photopolymer film carrying a holographic image of a bed of fuel and flame effect means co-operating with the holographic sheet whereby the flame effect appears to emanate from the holographic image of the fuel bed, resulting in a very realistic effect and allowing the depth of the apparatus to be reduced.

Abstract: A holographic memory system is disclosed. The holographic memory system comprises: a light source configured to generate a light beam; a photosensitive holographic storage medium configured to at least partially reflect the light beam; and an alignment module configured to determine an angular orientation of the storage medium based on the reflected light beam.