Abstract: A hologram recording method includes generating light of a pattern in which a plurality of unit blocks, which include at least one pixel and express luminance, are arrayed, the pattern being sectioned into a region of a signal beam and a region of a reference beam, and being generated such that the region of the reference beam includes a plurality of unit blocks whose numbers of pixels are different; collecting the generated light at a common optical system, and illuminating it onto an optical recording medium; and recording, as a hologram, data which the signal beam expresses.

Abstract: An apparatus for reading from or writing to holographic storage media, and more specifically a common aperture type apparatus for reading from or writing to holographic storage media with multiple reference beams having a reduced noise. In a common aperture type apparatus for reading from or writing to a holographic storage medium using shift-multiplexing, with a coaxial arrangement of two or more reference beams and an object beam or a reconstructed object beam, the reference beams being arranged around the object beam or the reconstructed object beam in a storage layer of the holographic storage medium. Each of the reference beams is located essentially halfway between two adjacent central peaks of shift-multiplexed holograms.

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: 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: An apparatus for producing a hologram of an object includes a light source that emits an incoherent electromagnetic wave toward the object, and a masking device configured to display a mask, receive the incoherent electromagnetic wave emitted toward the object, mask the received incoherent electromagnetic wave according to the displayed mask, and produce a masked electromagnetic wave. The apparatus also includes an image recording device configured to capture an image of the masked electromagnetic wave, and a processing device configured to convert the image of the masked electromagnetic wave into the hologram of the object. A method for producing a hologram of an object is also described.

Abstract: A holographic storage medium includes a hologram including data recorded in a plurality of pages in a superimposed fashion by interference of a signal beam and a reference beam, and an additional page recorded between two adjacent pages in the plurality of pages, wherein a portion of the data is recorded to a region of the additional page having a relatively small selectivity compared to other regions of the additional page without recording on the other regions.

Abstract: A system and method for illuminating an object in preparation for three-dimensional rendering includes a projection device configured to project at least three two-dimensional structured light patterns onto a 3-dimensional object. At least two cameras detect light reflected by the object in response to the at least three structured light patterns. Each structured light pattern varies in intensity in a first dimension and is constant in a second dimension. A single line along the first dimension of a given structured light pattern is created from a superposition of three or more component triangular waveforms. Each component triangular waveform has an amplitude, a periodicity (frequency), and a phase shift which is implemented as a pixel shift. Each component triangular waveform may be subject to one or more waveshaping operations prior to being summed with the remaining component triangular waveforms. The summed waveform itself may also be subject to waveshaping operations.

Abstract: A hologram decoding apparatus includes: an imaging device that receives a reproduced image obtained by reading an encoded image from a hologram recording medium in which a Fourier transform image of the encoded image with n pixels representing digital information is recorded, n being an integer of 2 or more, and that outputs the reproduced image with k resolution pixel numbers, k being an integer more than n; a storing unit that stores decoding patterns and digital information corresponding to the decoding patterns, wherein a decoding pattern from among the decoding patterns corresponds to the reproduced image, which is encoded with m pixels of k?m>n; and a decoding unit that refers to the decoding patterns to specify the decoding pattern; and that carries out a decoding process to set the digital information corresponding to the specified decoding pattern as digital information of the reproduced image.

Abstract: An image projecting apparatus enables the formation of a projected image faithful to original image information by reducing degradation in the projected image due to decrease in imaging performance of a projection optical system. Image information is processed by an image processing device, which includes a first and a second image processor. A light modulating device modulates a flux of light emitted by an illumination optical system based on the processed image information. The modulated flux of light is projected on a screen by a projection optical system. If the image information processed by the first image processor in a pixel region is not within a representable modulation range of the light modulating device, the image information is processed by the second image processor.

Abstract: [Object] Provided are a hologram generating device and a hologram generating method that allows the generation of a hologram for reproducing an easily observable three-dimensional image without restrictions on object sizes.

Abstract: A hologram element that forms a predetermined illumination pattern on an irradiated surface by diffracting incident light is disclosed. The illumination pattern is formed by making light in a first wavelength region diffracted in a first region, and the illumination pattern is formed by making light in a second wavelength region different from the first wavelength region diffracted in a second region on the same plane as the first region.

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 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: 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: 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 and system for micromanipulation of objects of any shape. The method and system creates various forms of holographic optical traps for a variety of commercial purposes. Some alternate forms of traps include a dark form of optical traps, optical vortices with different helical winding numbers and optical traps with variable phase profiles imprinted thereon.

Abstract: There is proposed a hologram recording method that includes: generating signal light by superimposing a periodic intensity distribution or phase distribution on an intensity distribution of light that expresses binary digital data as a light/dark image; Fourier transforming the signal light; illuminating Fourier transformed signal light and reference light simultaneously on an optical recording medium; and recording the signal light as a hologram.

Abstract: The present invention relates to a coaxial type apparatus for reading from and/or writing to holographic storage media with multiple reference beams. The invention further relates to a beam generator and a filter for use in such an apparatus. According to the invention, in an apparatus for reading from and/or writing to a holographic storage medium, with a coaxial arrangement of three or more focused reference beams and an object beam or a reconstructed object beam, the foci of the focused reference beams are arranged on a circle around the object beam in a Fourier plane of the apparatus. A beam generator generates the three or more reference beams from an incoming reference beam. A filter low-pass filters the object beam and rotates the polarization of the three or more reference beams.

Abstract: There is provided a data playback method including: acquiring first image data by illuminating reference light for reading onto an optical recording medium on which a hologram has been recorded by Fourier transforming and simultaneously illuminating reference light and signal light expressing digital data as a light-and-dark image, and detecting an inverse Fourier-transform image of diffracted light which is diffracted by the recorded hologram; acquiring second image data, which is a reversal image of the first image data, by generating combined light by combining the diffracted light and a dc component whose phase is different than a phase of a dc component of the signal light included in the diffracted light, and detecting an inverse Fourier-transform image of the combined light; and computing a difference in luminance for each pixel of the light-and-dark image, by carrying out computing processing by using the first and second image data.

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: A method produces colored individualized holograms for use as security elements for documents, and to a device for producing individualized holograms. The method generates light formed of different colors, spatially modulates the light, color by color, in an individual manner, optically guides the modulated light such that the light is at least partially refracted and/or reflected on a holographic master and is superposed in a holographic recording material with the modulated non-refracted and/or reflected light, and records the hologram. The light is modulated, color by color and at the same time, by a plurality of spatial light modulators. Every color is associated with its own spatial light modulator and a plurality of monochrome modulated light beams of the plurality of colors is combined in a collinear manner prior to refraction and/or reflection on the holographic master and the superposition in the recording material to give a multicolor exposure light beam.

Abstract: Provided is a digital holography device having a simple configuration and an improved image quality, including: a light source that emits light, the light source being provided for supply of object light beams formed by radiation, transmission, scattering, reflection, or diffraction of the emitted light from a subject; an array device that splits the light emitted from the light source into two kinds of reference light beams having different phases in a plane perpendicular to a direction in which the light emitted from the light source travels; a CCD camera having an image-capturing plane on which two kinds of interference fringe patterns are recorded, the interference fringe patterns being formed by interferences between the two kinds of reference light beams, which have been produced by the array device, and the object light beams, which have been formed by radiation, transmission, scattering, reflection, or diffraction from the subject; and an image reconstruction device that generates a reconstructed imag

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 device for producing a two dimensional image includes means for generating coherent light, and means for directing light received from the means for generating coherent light to a plurality of electrically addressable spatial light modulators (EASLM). The device includes means for diffracting the light, wherein the light is simultaneously diffracted by the plurality of EASLM, and means for displaying the two dimensional image. The device further includes means for directing the diffracted light to the means for displaying the two dimensional image, wherein a frame rate of each of the plurality of EASLM is greater than a frame rate of the two dimensional image produced at the means for displaying the two dimensional image.

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 holographic recording apparatus 10 realizes multilevel gray-scale recording by: controlling a reflection type spatial light modulator (DMD 18D) via a control unit 24 so that an object beam in an object optical system 18 is reflected in an exposure direction so as to be incident on a holographic recording medium 16 or in a non-exposure direction so as not to be incident thereon selectively pixel by pixel in accordance with a data page to be recorded; and making (N+1) levels of gradation exposure with a single exposure time t1 given by dividing t0 by N, where t0 is an exposure time necessary for rendering a single pixel of the data page as an ON pixel, and N is an integer of not less than 2.

Abstract: A method for forming an information recording layer including a multilayer stack of reflection hologram layers modulated in the depth direction of a hologram material layer is provided. The method includes: generating a first pair of polarized coherent laser beams and a second pair of polarized coherent laser beams that are incoherent with the first pair; directing the first pair of polarized coherent laser beams to the hologram material layer from opposite sides thereof, respectively, such that the incident angles of the first pair are symmetric with respect to the hologram material layer; directing the second pair of polarized coherent laser beams to the hologram material layer from the opposite sides thereof, respectively, at incident angles different from the incident angles of the first pair; and forming the multilayer stack of reflection hologram layers according to the interference pattern of the first and second pairs of polarized coherent laser beams.

Abstract: A hologram recorder (A2) includes: a light source (10) for emitting a coherent beam; a spatial light modulator (20) provided with unit areas having a plurality of beam reflection elements (21) to reflect the beam from the light source (10) in a main direction as a signal beam or a cut-off direction; and a signal beam optical system (30, 31) for directing the signal beam to the hologram recording medium (B). The recorder (A2) further includes: a wavefront reshaper (40, 41, 42) for condensing the beams thinned out in the cut-off direction by the beam reflection element (21) of the modulator (20), and reshaping the wavefront of the condensed beams; and a reference beam optical system (50, 51) for directing the beam from the reshaper (40, 41, 42) to the recording medium (B) as a reference beam to be shone in an overlapping manner with the signal beam.

Abstract: A hologram recorder applies a recording beam (S) and a reference beam (R) to the illumination site (p) of a hologram recording medium (B). The interference between the recording beam (S) and the reference beam (R) produces multiple hologram recording at the illumination site (p). The recorder includes a recording-purpose reference beam reflector (10) for reflecting the reference beam (R) to the illumination site (p), and a pivot mechanism for pivoting the reflector (10) about an axis (x) to vary the incident angle (?r) of the reflected reference beam (R) to the recording medium (B). The reflector (10) is disposed to cross a predetermined optical path. The axis (x) of the pivot mechanism is so arranged that the reflected reference beam (R) is directed to the illumination site (p) even when the incident angle (?r) of the beam (R) changes due to the pivoting of the reflector (10).

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: An analytical method for computing a video hologram for a holographic reproduction device having at least one light modulation means is disclosed, wherein a scene split into object points is encoded as a whole hologram and can be seen as a reconstruction from a visibility region, located within a periodicity interval of the reconstruction. The visibility region, together with each object point of the scene to be reconstructed, defines a subhologram and the whole hologram is generated from a superposition of subholograms, wherein the complex hologram values of a subhologram are determined from the wave front of the respective object point to be reconstructed in a modulator region of the light modulation means, by calculating and evaluating the transmission or modulation functions of an imaging element formed in the modulator region. The object point to be reconstructed is located in the focal point of the imaging element.

Abstract: A hologram recorder (A) records holograms in a selected unit recording area (B1) of a hologram recording medium (B) by interference between a recording beam (Lr) which is applied vertically to the unit recording area (B1) and a reference beam (Lr) which is applied obliquely to the unit recording area (B1). The hologram recorder (A) includes a reference beam oblique applier (23A, 23B) for application of the reference beam (Lr) obliquely to the unit recording area (B1) by reflection, and a reference beam swing mechanism (30) for supporting the reference beam oblique applier (23A, 23B) and for swinging the reference beam oblique applier (23A, 23B) about a predetermined rotation axis which is perpendicular to an entering direction of the recording beam (Lw) that makes an entry into the unit recording area.

Abstract: An apparatus and a method for reading from and/or writing to holographic storage media using a coaxial arrangement of an object beam and one or more reference beams or a coaxial arrangement of a reconstructed object beam and one or more reference beams is proposed. A focus of the one or more reference beams within a holographic storage medium is shifted along the optical axis relative to a focus of the object beam or the reconstructed object beam.

Abstract: A holographic recording medium includes a recording layer on a substrate, which records data information in a light interference pattern. 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: Disclosed are an apparatus and a method for displaying hologram of a mobile communication terminal. The present invention can create hologram from two-dimensional image by providing a hologram processing function for a mobile communication terminal and provide the hologram to a user. Further, the mobile communication terminal with the hologram processing function can perform medical diagnosis on a user, and thus can save a life by performing accurate medical diagnosis in emergency through hologram communication with an emergency center.

Abstract: A recording apparatus performing at least recording with respect to a hologram recording medium is disclosed. The recording medium includes: a light emitting means for emitting light to be radiated with respect to the hologram recording medium set at a prescribed position; a spatial light modulation means configured to be able to generate reference light and signal light to be radiated to the hologram recording medium by performing light intensity modulation to incident light in the unit of pixels; a phase modulation means for performing phase modulation to radiated light from the spatial light modulation means; and an optical system configured to guide light emitted from the light emitting means with respect to the hologram recording medium through the spatial modulation means and the phase modulation means.

Abstract: An apparatus for producing a hologram mask. The apparatus includes a first object light at least partially transmittable through a first original mask having a light transmitting screening pattern, and a first reference light having a first phase difference between it and the first object light. The first object and reference lights cause interference patterns to be recorded a hologram recording material, as do a second object light at least partially transmittable through a second original mask having a light transmitting screening pattern, and a second reference light having a second phase difference between it and the second object light where the second phase difference is not the same as the first phase difference. The resulting first and second original mask images recorded in the hologram recording material can be simultaneously replayed to produce an exposed pattern approximating an exposed pattern of a non-holographic phase shifting photomask.

Abstract: A hologram recording apparatus includes a light source for irradiating coherent light, light separator for separating the coherent light into light for reference beam and light for signal beam, optical path changer for changing an optical path of each light separated by the light separator so that the reference beam and the signal beam may be irradiated simultaneously onto an optical recording medium, a spatial light modulator disposed in the optical path of the light for the signal beam for modulating the light for the signal beam in accordance with a supplied recording signal to create signal beam for recording a hologram, and diffused light irradiator for irradiating diffused light simultaneously with the reference beam at least onto an area of the optical recording medium where the reference beam is irradiated.

Abstract: A device and method for mass producing reflection holograms. Photosensitive material is drawn across an object to be copied and coherent radiation is scanned across the material and the object. The object may comprise a component which is variable, such as a counter, or a hologram. The exposed photosensitive material is removed from the object, the symbols on the object are changed if desired, fresh material is moved into place, and a new hologram is created. The holograms of the present invention preferably have the capability to be sequentially or individually numbered or otherwise customized with a variety of symbols, for example for security purposes.

Abstract: An optical code division multiple access (OCDMA) system includes an optical transmitter system configured to transmit data from a plurality of users through a shared optical channel by encoding the data from each user with a spreading code assigned to that user. Each spreading code includes a unique sequence of T time chips along a time axis. The data from each user is representable by T symbols. The OCDMA system further includes an optical receiver system configured to demodulate the data from each user by correlating signals received from the transmitter system with the spreading code assigned to that user. When transmitting a data symbol for each user, the transmitter system selects one out of T distinct cyclic shifts of the spreading code assigned to that user, and transmits the selected cyclic shift of the assigned spreading code along the time axis.

Abstract: A hologram recording and reproducing apparatus includes a movable galvanomirror, a mirror controller and a reproduction unit. The galvanomirror guides a reference beam toward a hologram recording medium and changes the incident angle of the reference beam. The mirror controller causes the galvanomirror to move for adjusting the incident angle to a predetermined angle for hologram recording. In reproducing the recorded information, the mirror controller causes the galvanomirror to move, so that the incident angle continuously changes within a predetermined range including the predetermined angle. The reproduction unit receives a detection signal from an optical detector while the incident angle changes continuously. The detection signal corresponds to the intensity of a reflected beam from the hologram recording medium. The reproduction unit reproduces the recorded information, based on the detection signal, when the intensity of the reflected beam is over a predetermined level or reaches the maximum.

Abstract: An apparatus for reading from and/or writing to transmission type holographic storage media is proposed, and more specifically a coaxial type apparatus for reading from and/or writing to transmission type holographic storage media with two or more reference beams, which has an improved Signal to Noise Ratio. The apparatus has a coaxial arrangement of two or more reference beams and an object beam or a reconstructed object beam. The reference beams are arranged on a circle around the object beam or the reconstructed object beam in a Fourier plane of the apparatus behind the holographic storage medium. A mirror is located in or close to this Fourier plane, which is designed such that it reflects the object beam or the reconstructed object beam without reflecting the reference beams.

Abstract: Holographic storage system with multiple reference beams An apparatus for reading from and/or writing to holographic storage media is described, and more specifically an apparatus for reading from and/or writing to holographic storage media with two or more reference beams that overlap inside the holographic storage medium for reading and/or writing a single hologram. The two or more reference beams are mutually incoherent during reading and/or writing.

Abstract: The present invention relates to a method for recording data pages in a holographic recording medium, and more specifically to a method for compensating for sensitivity variations of the holographic material of the holographic recording medium. According to the invention, a method for recording data pages on a holographic recording medium has the steps of: modulating a light beam with a spatial light modulator to generate a data page with data to be recorded, and applying a compensation profile to the data pages during recording for reducing contrast variations in the reconstructed data pages, wherein the compensation profile is determined from the irradiation history at the recording position and the sensitivity curve of the material of the holographic recording medium.

Abstract: A reflection type collinear holographic storage system is described, in which an improved overlap between an object beam and a reference beam is achieved. The collinear holographic storage system has a spatial light modulator for imprinting a data page on an object beam, which is located in the beam path of a portion of a reference beam transmitted through a holographic storage medium, whereby the object beam is generated by imprinting a data page onto the transmitted reference beam. The diameter of the reference beam inside the holographic storage medium is matched to the diameter of the object beam.

Abstract: An integrated planar optical device having a holographic pattern based on digital planar holography [incomplete sentence]. The device consists of a semiconductor substrate that supports a plurality of planar optical elements and a lower cladding layer. The lower cladding layer supports a light-propagating and distributing layer, embedded into which is a plurality of interconnecting pattern elements of a holographic pattern intended for controlling properties and directions of light beams propagating to and from the aforementioned planar optical elements in accordance with the holographic pattern. This is achieved by providing specific positions, shapes, and a refractive index of pattern elements that are different from the refractive index of the material of the layer that contains these elements. The method of designing and manufacturing the aforementioned pattern is described.

Abstract: A system and method for illuminating an object in preparation for three-dimensional rendering includes a projection device configured to project at least three two-dimensional structured light patterns onto a 3-dimensional object. At least two cameras detect light reflected by the object in response to the at least three structured light patterns. Each structured light pattern varies in intensity in a first dimension and is constant in a second dimension. A single line along the first dimension of a given structured light pattern is created from a superposition of three or more component triangular waveforms. Each component triangular waveform has an amplitude, a periodicity (frequency), and a phase shift which is implemented as a pixel shift. Each component triangular waveform may be subject to one or more waveshaping operations prior to being summed with the remaining component triangular waveforms. The summed waveform itself may also be subject to waveshaping operations.

Abstract: A recording medium is stacked on a master recording body, to which reference beams are applied each at an incident angle. The interference between diffracted beams diffracted in the data storage sections of the master recording body and the reference beams in the recording medium occurs such that the data are transferred to the recording medium. The use of plural compact light sources for emitting the reference beams allows the recording device to be compact while reducing the power consumption.

Abstract: A slab optical waveguide confines in one transverse dimension optical signals propagating in two dimensions therein, and has a set of diffractive elements collectively arranged so as to exhibit positional variation in amplitude, optical separation, or spatial phase. The diffractive elements are collectively arranged so as to apply a transfer function to an input optical signal to produce an output optical signal. The transfer function is determined at least in part by said positional variation in amplitude, optical separation, or spatial phase. The waveguide and diffractive elements are arranged so as to confine only one of the input and output optical signals to propagate in the waveguide so that the optical signal thus confined is successively incident on the diffractive elements, while the other optical signal propagates unconfined by the waveguide in a direction having a substantial component along the confined dimension of the waveguide.