Abstract: The invention provides a hologram in which a visually unidentifiable microtext or other micropattern of the order of 10 ?m is recorded, and a process for the fabrication of the same. A volume hologram recording material 2 is located on the side of a reflection type volume hologram master 1 onto which copying illumination light 11 is incident, and the copying illumination light 11 incident onto the recording material 2 and light 12 diffracted through the master 1 interfere together in the volume hologram recording material 2 thereby copying the reflection type volume hologram master.

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: The present invention is directed to a method of integrating information, including real-time information, into a virtual thematic environment using a computer system, including accessing the stored information from a database or downloading the real-time information from a source external to the thematic environment; inserting the real-time information into the thematic environment; and displaying the information to a user within the thematic environment. In one embodiment, the computer system is connected to a holographic projection system such that the images from the thematic environment can be projected as holographic projections.

Abstract: A holographic display including a spatial light modulator, and including a position detection and tracking system, such that a viewer's eye positions are tracked, with variable beam deflection to the viewer's eye positions being performed using a microprism array which enables controllable deflection of optical beams.

Abstract: The present invention relates to a method for the production of polarization holograms, an apparatus for the production of polarization holograms and the use of the polarization holograms according to the invention as data stores, security features or diffractive optical elements for performing conventional optical functions.

Abstract: A holographic storage system having an improved data page quality is described. The holographic storage system includes a special optical filter or a special light source for emphasizing the high frequency components of a reference beam and/or an object beam. This is achieved by an optical filter arranged in a Fourier plane, which has a higher attenuation at the center than at the edge. Alternatively, an adapted light source for generating the reference beam and/or the object beam is arranged in a Fourier plane. The light beam emitted by the light source has a higher intensity close to the edge than at the center.

Abstract: According to one aspect and example, a holographic recording system includes a light source, an object for modulating an object beam from the light source, and a relay system adapted to magnify (positive or negative) the modulated beam (e.g., an image of the object) to an output image. The object may include an SLM operable to modulate the object beam with an information layer comprising a plurality of data pages. The output image is directed to the holographic storage medium, where a reference beam is also directed, to record the resulting interference pattern. Additionally, the relay system converges the output image to an output Fourier plane, which may be disposed within the holographic storage medium. A filter may be placed at an intermediate Fourier plane located prior to the output Fourier plane, and a phase mask may be placed at the position of the output image.

Abstract: The present invention relates to a holographic storage system, and more specifically to a method for pixel detection in a coaxial holographic storage system. In a holographic storage system according to the invention, with a coaxial arrangement of an object beam and a reference beam the bright pixels within the object beam have a phase shift of essentially ? relative to the reference beam. For readout of a data page contained in a reconstructed object beam a detector detects an interference pattern generated by the interference between the reference beam and the reconstructed object beam.

Abstract: An apparatus and method to produce a hologram of an object includes an electromagnetic radiation assembly configured to receive a received electromagnetic radiation, such as light, from the object. The electromagnetic radiation assembly is further configured to diffract the received electromagnetic radiation and transmit a diffracted electromagnetic radiation. An image capture assembly is configured to capture an image of the diffracted electromagnetic radiation and produce the hologram of the object from the captured image.

Abstract: An optical unit includes an acousto-optic deflector and a drive control unit. The drive control unit controls the acousto-optic deflector by changing a frequency of a voltage applied to an acousto-optic medium of the acousto-optic deflector to a frequency in a first frequency range during a first period representing a deflection control period and changing the frequency of the voltage to a frequency in a second frequency range different from the first frequency range during a second period representing a transmittance control period.

Abstract: A holographic data storage system that includes a write head that includes a pixellated spatial light modulator and a separate or integral phase mask that varies the phase depending on the location in the phase mask that light passes through. The phase variation can be changed over time in a random, pseudo-random, or predetermined fashion. The spatial light modulator and phase mask can be implemented in a liquid crystal SLM (nematic, ferroeleletric, or other), in a DMD SLM, in a magneto-optical SLM, or in any other suitable manner.

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 comprising holographic storage media for recording or for reading recorded data using such devices or systems.

Abstract: A method for holographic data recording and simultaneous data readout without requiring additional optical power for readout illumination is provided. The method comprises reflecting a transmitted portion of a data light beam or of a reference light beam used for holographic recording of data in a holographic data storage medium. The reflected beam is configured to illuminate the holographic data storage medium from the opposite side with a polarization orthogonal to that of the recording beams, such that it provides a counter-propagating readout beam for real-time readout of currently being recorded hologram. Readout beam may also be configurable for accessing any one of the at least one previously recorded holograms. Systems using the methods of the invention are also provided.

Abstract: A holographic storage system for reading a hologram stored on a holographic storage medium. The system comprises: storage medium holding means; a spatial light modulator (SLM) for encoding a reference beam with a code pattern; a detector; and a servo control unit for determining a misalignment of the reference beam and the storage medium from the detected image and for acting upon the SLM to shift the code pattern. A method of reading a hologram stored on a holographic storage medium comprising: a) encoding a reference beam with a code pattern created by a spatial light modulator (SLM); b) detecting an image of the reconstructed hologram; c) determining a misalignment of the reference beam and the storage medium from the detected image; and d) shifting the code pattern on the SLM based at least in part on the misalignment.

Abstract: A holographic imaging system includes an electrical addressable spatial light modulator (EASLM) and an optically addressable spatial light modulator (OASLM). A read light is configured to illuminate the OASLM, and a controller is configured to address the EASLM with both positive and negative sub-images and transmit the positive and negative sub-images to the OASLM. The controller is further configured to address the OASLM with an operating voltage, wherein the read light generates a holographic image comprised of diffraction patterns from the positive and negative sub-images.

Abstract: This invention relates to holographic image display systems, and to related methods and processor control code. We describe a method of displaying an image holographically, the method including: inputting display image data defining said image for display; processing said image data to determine first image data representing a first spatial frequency portion of said image data and second image data representing a second spatial frequency portion of said image data, wherein said second spatial frequency is higher than said first spatial frequency; displaying a hologram of said first image data on a spatial light modulator (SLM) to form a holographically-generated intermediate real image; modulating said intermediate real image using said second image data to display said image.

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 hologram recording apparatus includes a signal-beam spatial light modulating section, a reference-beam spatial light modulating section, and a control unit. A signal beam pattern generates a signal beam. A reference beam pattern generates a reference beam. The control unit controls the shapes of the two beam patterns. A data-recording signal beam pattern is displayed on the signal-beam spatial light modulating section and a data-recording reference beam pattern is displayed on the reference-beam spatial light modulating section so that a data-recording hologram is formed in a predetermined area of a holographic recording medium. An encryption signal beam pattern for encrypting the data-recording hologram is displayed on the signal-beam spatial light modulating section and an encryption reference beam pattern is displayed on the reference-beam spatial light modulating section so that an encryption hologram is formed in the same area as the predetermined area of the holographic recording medium.

Abstract: Methods and devices are described for creating and printing holographic stereograms and holographic optical elements using computer rendered images or using computer processed images. Various embodiments of the system may utilize interchangeable band-limited diffusers and reference-beam masking plates.

Abstract: A holographic recording system (1) includes a transparent or semi-transparent holographic recording medium (6), a source of coherent optical radiation (7), and an optical system (10). The recording medium has a first side (25) presented toward the radiation source, a second side (26) opposite to the first side and presented toward the optical system, and a recording volume (30) between the two sides. The radiation source is arranged to project incident optical radiation (20) onto the first side and through the recording volume towards the optical system, which is arranged to redirect (32) the optical radiation back onto the second side and into the recording volume so that the incident and redirected radiation intersect within the recording volume at an obtuse angle (34) to create an interference pattern (38) from which a holographic recording may be made.

Abstract: The present invention discloses a wavelength-multiplex and space-multiplex holographic storage device, which comprises a storage medium, a plurality of signal light beams and at least one reference light beam. The signal light beams have different wavelengths and illuminate the storage medium. The reference light beam illuminates the storage medium and interferes with the signal light beams to form a plurality of interference patterns. The interference patterns are respectively stored on different-depth storage layers of the storage medium. The present invention not only has a high access rate but also has a large storage capacity.

Abstract: A target image 60 is multiplied by an appropriate phase pattern to provide a phase modified image 61 to which an inverse Fourier transform is applied to generate a source hologram 62. A set of intermediate holograms 63 are generated from the source hologram 62 using vertical and/or horizontal shifts of the source hologram 62. A set of final holograms 64 are generated from the set of intermediate holograms 63 using sum and/or differencing of various members of the set of intermediate holograms 63. Each final holograms 64 is approximated to form kinoforms 65 for sequential display to an observer 66 as illuminated subframes 67a to 67d. The observer 66 perceives only one image formed from a number of subframes 67a to 67d, wherein the noise associated with the kinoforms 65 averages over time and the observer 66 perceives an attenuation of such noise.

Abstract: A medium 1, that is a laminated holographic medium of the present invention is composed of two or more core layers 2; 3 or more cladding layers 3 set so as to bind the core layers 2; one or more diffraction grating layers 4 storing information data and set at a boundary between a portion of the core layers 2 and the cladding layers 3 binding the core layers 2 or set inside the core layers 2; and one or more recording layers 42 storing information data as forms or a refractive index distribution and set at a boundary between a portion of the core layers 2 and the cladding layers 3 binding the core layers 2 or inside the core layers 2 through or without a gap layer.

Abstract: In a holographic information recording and reproducing apparatus, an optical fiber guides a reference beam toward a recording medium for holographic recording, and a precision rotator is turned, so that the reference beam is incident on the recording medium at different angles and interferes with a data-carrying signal beam to complete the recording of holographic information on the recording medium. To reproduce the holographic information, the optical fiber guides a reading beam, and the reading beam is incident on the recording medium at an angle the same as the reference beam for the recording to reproduce the holographic information stored on the recording medium. With the optical fiber and the precision rotator, a simplified light path system and a wide range of incident angles for the reference and reading beams may be achieved, and the transmissive, reflective, and 90-degree holographic storage techniques may be integrated in one single apparatus.

Abstract: A holographic recording medium including a recording layer on a substrate, which records data information in a light interference pattern. 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: A system and method for holographic lithography is disclosed, including interferometeric alignment of laser sources. This includes creation of the volumetric holographic pattern around wire and other planar and non-planar substrates. This template is further processed into devices for various applications including Photonic Crystals, Photonic Band Gaps, Photonic Band Gaps with selective defects, and Photonic Band Gap incandescent emitters.

Abstract: A method to encode information holographically, wherein the method provides information, and generates a plurality of data images, wherein each data image comprises a portion of the information. The method holographically encodes each of the plurality of data images in a holographic data storage medium, generates a plurality of identifiers, and associates a different one of the plurality of identifiers with a different one of the plurality of data images. The method forms a directory image reciting each of plurality of identifiers, encodes the directory image in a non-holographic data storage medium, and holographically encodes the directory image in the holographic data storage medium.

Abstract: Non-rigidly coupled, overlapping, non-feedback optical systems for spatial filtering of Fourier transform optical patterns and image shape characterization comprises a first optical subsystem that includes a lens for focusing a polarized, coherent beam to a focal point, an image input device that spatially modulates phase positioned between the lens and the focal point, and a spatial filter at the Fourier transform pattern, and a second optical subsystem overlapping the first optical subsystem includes a projection lens and a detector. The second optical subsystem is optically coupled to the first optical subsystem.

Abstract: An updateable system and method of recording a hologram on a media simultaneously reduces the writing time and increases persistence without sacrificing diffraction efficiency. A voltage kick-off technique controls the bias electric field applied to a photorefractive polymer media in conjunction with the application of the writing beams and dark decay. Essentially the voltage kick-off technique applies a high electric field above the optimal field while the writing beams are on and reduces the electric field when the writing beams are off during dark decay. The voltage kick-off technique produced two separate unexpected results. First, when the writing beams are turned off and the electric field is lowered the diffraction efficiency continues to increase until it reaches a maximum efficiency that is within a few percent of that achieved by writing at the optimal field until steady-state is achieved.

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: Information light modulated and emitted by a modulation element is led to a recording medium through a Fourier transform optical system and an optical path shifter. An interference image is recorded on the recording medium by interference of the information light and reference light. A deflection unit of the optical path shifter has a pair of prisms. Optical path of information light transmitted through the respective prisms are shifted in parallel in a direction perpendicular to an optical axis of the Fourier transform optical system. By rotating the deflection unit around the optical axis, it is possible to shift the optical path of the information light around the optical axis while shifting the optical path in the direction perpendicular to the optical axis. Therefore, it is unnecessary to perform complicated control and it is possible to multiply record an interference image accurately with an information recording apparatus having a simple structure.

Abstract: A holographic memory system includes a spatial light modulator having multiple modulators for spatially modulating at least a portion of a light beam emitted from a light source and rendering it as an information light beam, and a light sensing device for reading the information light beam taken out of a recording medium. The spatial light modulator and the light sensing device are integrally formed on the same substrate.

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: A holographic recording and reproducing apparatus includes a spatial light modulator, a Fourier transform lens, a reverse Fourier transform lens, a Charge Coupled Device (CCD) image sensor, and a pinhole disposed at a confocal point of the Fourier transform lens and the reverse Fourier transform lens, the holographic recording medium being disposed between the Fourier transform lens and the reverse Fourier transform lens, and the focal length of the Fourier transform lens and focal length of the reverse Fourier transform lens being different from each other, and the pinhole being disposed between the holographic recording medium and the Fourier transform lens or between the holographic recording medium and the reverse Fourier transform lens.

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: 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: A light valve assembly comprises a holographic optical element and a light valve that comprises an array of individually addressable pixels. The light valve assemblies can be fabricated on the die level or on a wafer-level.

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 method for compensating for a wavelength mismatch between a readout reference beam and a recording reference beam in a holographic storage system is described. In order to compensate for a wavelength mismatch in a first step the wavelength mismatch is determined. In a second step the direction of at least part of the readout reference beam is adjusted relative to a holographic storage medium in dependence on the determined wavelength mismatch by defocusing the readout reference beam or by adjusting the focal length of an objective lens for focusing the readout reference beam into the holographic storage medium.

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: 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 compact apparatus for reading from and/or writing to holographic storage media and polarizing filter for use in such an apparatus includes a substrate with an outer zone and an inner zone, the outer zone and the inner zone having different optical properties for a first direction of polarization and a second direction of polarization, and a wave plate attached to the substrate for influencing the polarization of the a light beam, wherein a part of the wave plate corresponding to either the outer zone or the inner zone is switchable.

Abstract: A holographic storage and regeneration system includes a holographic recording medium, a light source, a spatial light modulator, and a conjugate servo light guidance portion. The light source generates a signal light and a reference light. The spatial light modulator modulates the incident signal light and makes it incident onto the medium along the incident direction of the signal light. The guidance portion guides a reference light to incident onto the medium in one direction and reflects it in another direction. A reference light and a signal light interfere with each other to produce a holographic interference fringe. The reflected reference light is guided into a first image sensor to be used to analyze the incident angle of the reference light. When the reference light incidents onto the fringe of the medium through the guidance portion in a reverse direction relative to another direction, a conjugate regenerated light is generated.

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 laser beam multiplexer capable of easily multiplexing a plurality of laser beams is provided. A laser beam multiplexer includes a multiplexing element having a hollow portion with a sectional elliptical shape, in which the multiplexing element includes: a plurality of light-incident apertures guiding laser beams from outside toward one of two focal points of the hollow portion, a reflective layer arranged on a wall surface of the hollow portion, and multiplexing a plurality of incident laser beams while reflecting the plurality of laser beams, and a light-emitting aperture guiding laser beams multiplexed by the reflective layer toward outside.

Abstract: Holographic stereograms and holographic optical elements are printed using computer rendered images of three-dimensional computer models or using computer processed images. A coherent beam is split into object and reference beams that interfere with each other at an elemental hologram on a holographic recording material. A voxel-control lens placed in the path of the object beam and in close proximity to the holographic recording material can be used to control the resolution of a holographic stereogram. Interchangable band-limited diffusers and reference-beam masking plates can assist exposure of the elemental hologram and avoid exposing portions of the holographic recording material that are not part of the elemental hologram.

Abstract: A harmonic holography (H2) technique and system that combines holography and nonlinear optics that enables holographic recording of 3D images with femtosecond framing time are provided. The H2 technique records holograms with second harmonic (SH) signals scattered off specialized nanocrystals that are functionalized to label specific protein or other biomolecules in a living organism. The capability of generating second harmonic radiations is specific to materials with noncentrosymmetric crystalline structures only, and ?(2) vanishes for all other types of materials. Therefore, a sharp contrast is formed when particles of noncentrosymmetric structures are dispersed in a medium of other species, pumped at a fundamental frequency, and imaged at the second harmonic frequency. The new scheme described herein provides a sound basis for a new type of contrast microscopy with enormous potential in molecular biomedical imaging.

Abstract: A hologram recording film has an image of a three-dimensional object, e.g. a three-dimensional model, recorded in a volume hologram photosensitive material and further has a hologram image of a plane color pattern, e.g. a character or an image, together with the shadow of the color pattern, recorded as individual information in a superimposed manner in the same photosensitive material without using a liquid crystal display. Pieces of plane additional information of the same pattern have been recorded so as to be capable of being reconstructed simultaneously in a hologram plane and in front of or behind the hologram plane, respectively, in superimposition with a reconstructed image from a volume hologram.

Abstract: A single method and apparatus for producing many of the most common types of hologram from digital data is disclosed. The data are generated entirely by a computer as a 3-D (animated) model or from multiple 2-D camera images taken of a real 3-D (moving) object or scene from a plurality of different camera positions. The data are digitally processed and displayed on a small high resolution spatial light modulator (SLM). A compact low energy pulsed laser, is used to record composite holograms. The present invention permits the creation of restricted or full parallax master transmission or reflection type composite holograms, known as H1 holograms, that can be copied using traditional methods. Alternatively the same invention and apparatus permits the direct writing of hologram without the need to pass through the intermediate stage of the H1 transmission hologram.

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.