Abstract: There is provided volume holographic data recording media having a recording layer which is capable of recording interference fringes generated by interference of light having excellent coherence as fringes having different refractive indexes and undergoes holographic data recording by an amount of spatial shift distance of not more than 3 ?m which is smaller than that of conventional media.

Abstract: HROM replication methods, devices or systems are disclosed herein. Also disclosed herein are articles comprising conical reference (reconstruction) beam hologram elements to generate conical or conical like reference (reconstruction) beams which may be used in such HROM replication methods, devices or systems. Further disclosed herein are articles comprising a target medium which may be used in such HROM replication methods, devices or systems.

Abstract: 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: Provided is a three-dimensional image projector capable of displaying a highly reproducible three-dimensional image in response to changes in a viewer's position and easily accomplishing system downsizing.

Abstract: A method of detecting and compensating fail pixels in a holographic storage system. The method includes steps of: providing a plurality of image frames to show on a data plane for all pixels on the data plane being capable of outputting a light state or a dark state; sequentially recording the image frames into a storage medium; detecting the image frames by using a detecting apparatus for all pixels on the detecting apparatus being capable of outputting sensing signals corresponding to the light state and the dark state; defining a sensing difference value, which is a difference of the sensing signal outputting the light state and the dark state generated by one pixel; comparing the sensing difference value with a threshold value; and defining the corresponding pixel is a fail pixel if the sensing difference value is smaller than the threshold value.

Abstract: A three-dimensional image display method, includes: displaying a three-dimensional image including a left eye image signal and a right eye image signal displayed at a display focus angle; determining whether to change a viewing focus angle with respect to the display focus angle; calculating a pixel distance between the left eye image signal and the right eye image signal if it is determined to change the viewing focus angle; and displaying indicator marks at positions spaced as much as a half of the pixel distance from a center of a screen in leftward and rightward directions.

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 multiplexed holographic recording apparatus records multiplexed holograms in a plurality of recording regions that are formed on a holographic recording medium. In particular, the apparatus first records a predetermined number of multiplexed holograms in each of the recording regions formed in a predetermined range or an overall range of the holographic recording medium through holographic recording performed N times, and then performs the (N+1)th holographic recording in each recording region formed in the predetermined range or the overall range. When n other recording regions (where n=0, 1, 2, . . . ) are superimposed on each recording region formed on the holographic recording medium, a difference in the degree of multiplexing between the recording regions formed in the predetermined range or the overall range of the holographic recording medium does not exceed a predetermined value of n+1.

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 hologram recording apparatus (300) is provided with: a recording device (100) for recording record information into a hologram recording medium (1); a measuring device (325) for measuring a time elapsed from when the recording of the record information is stopped to when the recording of the record information is restarted; a first controlling device (354) for controlling the recording device to multiplex-record the record information, if the measured elapsed time is shorter than a time length in which the record information can be multiplex-recorded; and a second controlling device (354) for controlling the recording device not to multiplex-record the record information, if the measured elapsed time is longer than the time length in which the record information can be multiplex-recorded.

Abstract: A method and apparatus for recording and/or reproducing data to and/or from a holographic storage medium and a holographic storage medium therefor are provided. The method of reproducing data from the holographic storage medium, in which a hologram containing data is recorded through interference between a signal beam and a reference beam, the data being recorded in pages and a plurality of the pages being recorded in a book, includes controlling the reference beam so that an increasing/decreasing order of a reference beam in a current book which is currently reproduced is reverse to an increasing/decreasing order of a reference beam in a previous book which was reproduced before the current book, and reproducing pages of the current book from the holographic storage medium according to the controlling of the reference beam.

Abstract: A holographic recording method, a holographic recording apparatus, a holographic recording and reproducing method, a holographic recording and reproducing apparatus, and a holographic recording medium for recording information in an angle multiplex fashion as a hologram in a first format in which either one of signal light and reference light branched out from a laser light source is made to cross the other in a recording layer at a predetermined incidence angle and the incidence angle is changed at a predetermined angular pitch, or in a second format of higher angular selectivity, wherein the incidence angle when recording information in the second format of higher angular selectivity can be adjusted to cover an incidence angle that satisfies the Bragg's condition when recording in the first format, thereby ensuring reproduction compatibility between media of different angular selectivities.

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 and system is disclosed for increasing the holographic storage capacity of a holographic recording medium using an irradiance-tailoring (e.g., optical) element by changing the irradiance profile of the modulated object beam (e.g., by imparting motion to an irradiance-tailoring element and/or the holographic recording medium and/or by reconfiguring (e.g., periodically) the phase profile of a stationary irradiance-tailoring (e.g., optical) element) to minimize the effects of fixed-pattern noise buildup from occurring in the holographic recording medium.

Abstract: A hologram reconstructing apparatus is disclosed. The apparatus includes: unnecessary light removing means for causing the imaging means to receive necessary light only included in the reconstruction light; driving means for operating the hologram recording medium or a reconstruction light optical system; light detecting means for detecting the state that reconstruction light is projected to the unnecessary light removing means of the light cut by the unnecessary light removing means; and control means for obtaining the displacement of the hologram recording medium based on the information on a specific part of the projection state information detected by the light detecting means and controlling the driving means to cancel the displacement and move the hologram recording medium or the optical system.

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 hologram recording medium including a substrate, a hologram recording layer that records an interference pattern formed by a first wavelength beam, a wavelength selecting reflection layer provided between the substrate and the hologram recording layer that reflects the first wavelength beam and transmits a second wavelength beam, a beam absorbing layer provided between the substrate and the wavelength selecting reflection layer that absorbs the first wavelength beam, and an information layer provided between the substrate and the light absorbing layer in which information is recorded and reproduced by the second wavelength beam, a second information layer provided between the substrate and the information layer and a second wavelength selecting reflection layer provided between the information layer and the second information layer that reflects the second wavelength beam and transmits a third wavelength beam.

Abstract: A hologram recording apparatus that records a hologram on a recording layer of a hologram recording medium by causing interference between signal light modulated in accordance with record data and reference light from the same light source as that of the signal light is provided. The apparatus includes: a signal light spatial light modulating section that displays a signal light pattern for causing the signal light; a reference light spatial light modulating section that displays a reference light pattern for causing the reference light; a control section that controls the form of the signal light pattern to be displayed on the signal light spatial light modulating section and the form of the reference light pattern to be displayed on the reference light spatial light modulating section and controls optical energy of the signal light and reference light; and a temperature sensor that senses the temperature of the hologram recording medium.

Abstract: A holographic memory system and apparatus, and a method provide the ability to store multibit holograms in a photorefractive crystal. A single laser diode is configured to emit a collimated laser beam to both write a page of multibit data to and read the page of multibit data from the photorefractive crystal. A multilevel spatial light modulator (DMDSLM) is configured to encode the page of multibit data on an input beam split from the collimated laser beam. A first imaging relay lens pair is positioned between the multilevel spatial light modulator and the photorefractive crystal to image a multibit spatial light modulator image on a plane behind the photorefractive crystal. One or more mirrors are configured to steer a reference beam, split from the collimated laser beam, at high speed to the photorefractive crystal to read or write a page of the multi-bit data.

Abstract: A hologram recording device for irradiating a recording beam (S) to a hologram recording medium (B) at a fixed incident angle (?s) and irradiating a reference beam (R) to an illuminated region (p) of the recording beam (S) by variably controlling an incident angle (?r) of the reference beam (R) on the hologram recording medium (B), whereby a hologram is recorded on the illuminated region (p) in multiple, includes at least a variable reflector (10) directing the reference beam (R) to the illuminated region by reflection and being swung around a predetermined axis (x) for changing the incident angle (?r) of the reference beam (R); and a light shield (11) being swung integrally with the variable reflector (10) for partially shielding the reference beam (R) so that a luminous flux diameter thereof becomes narrower as the incident angle (?r) becomes larger.

Abstract: A holographic recorder can vary the optical distance between an object lens and a relay lens near the object lens. This arrangement allows defocus-multiplexing utilizing state variations in the laser beam when the beam reaches a storage medium.

Abstract: A hologram recorder is provided, in which coherent light from a light source is split into a signal beam and a reference beam, and the signal beam is modulated by a spatial light modulator to be directed to a hologram recording medium, while the reference beam is directed to the hologram recording medium to overlap with the signal beam for recording a hologram on the hologram recording medium. The hologram recorder includes a beam phase modulator provided with a plurality of optical devices (20p, 20p?) each configured to assume one of two modes such as ON mode and OFF mode, the ON mode for causing the reference beam to be passed or reflected in a predetermined direction toward the hologram recording medium, the OFF mode for causing the reference beam to be blocked or directed in another direction other than the predetermined direction. Each optical device (20p, 20p?) provides a phase difference 0 or ?.

Abstract: The invention relates to a color hologram display an image of a three-dimensional object and a hologram image of a pattern of plane characters, images or the like are recorded in the same volume type hologram photosensitive material in a superposed or multiplexed fashion. A color hologram display 27? comprising a combined reflection and volume type of single layer, wherein a color pattern 29g of plane characters, images or the like and a color three-dimensional subject image O? are reconstructably recorded while spatially superposed one upon another.

Abstract: An apparatus for writing and reading holograms, comprising a spatial light modulator (SLM) operable in phase mode, having a plurality of pixels for generating an object beam that overlaps with a reference beam; a holographic recording medium (HRM) in the path of the object beam; and a first lens element disposed in the path of the object beam between the SLM and the HRM; wherein the HRM is disposed at or near the Fourier transform plane of the first lens element.

Abstract: The present invention relates to a method and a system for synthesizing a prescribed three-dimensional electromagnetic field based on generalized phase contrast imaging. Such a method and apparatus may be utilized in advanced optical micro and nano-manipulation, such as by provision of a multiple-beam optical tweezer.

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: This invention relates to holograms employing colour addition techniques, and to methods and apparatus for the fabrication of such holograms. The holograms are particularly useful for security applications. A volume reflection hologram storing at least two images, the hologram comprising: a first stored image configured to replay at a first wavelength; a second stored image configured to replay at a second wavelength different to said first wavelength; wherein said first and second images at least partially overlap when replayed together; and wherein said first and second wavelengths are selected such that where said first and second images overlap they give the appearance of a colour defined by a third wavelength different to both said first and second wavelengths.

Abstract: An apparatus for compensating for pixel distortion while reproducing hologram data includes an extraction unit, a determination and calculation unit, a table, and a compensation unit. The extraction unit extracts a reproduced data image from a reproduced image frame including the reproduced data image and borders. The determination and calculation unit determines position values of edges of the extracted reproduced data image, and calculates average magnification error values of pixels within line data from position values of start and end point pixels thereof, which are based on the determined position values of the edges. The table stores misalignment compensation values for the pixels within the line data, wherein the misalignment compensation values correspond to predetermined references for average magnification error values.

Abstract: An apparatus for writing and reading holograms, comprising a spatial light modulator (SLM) operable in phase mode, having a plurality of pixels for generating an object beam that overlaps with a reference beam; a holographic recording medium (HRM) in the path of the object beam; and a first lens element disposed in the path of the object beam between the SLM and the HRM; wherein the HRM is disposed at or near the Fourier transform plane of the first lens element.

Abstract: A reproducing device for performing reproduction regarding a hologram recording medium where a hologram page is recorded in accordance with signal light, by interference between the signal light where bit data is arrayed with the information of light intensity difference in pixel increments, and reference light, includes: a reference light generating unit to generate reference light irradiated when obtaining a reproduced image; a coherent light generating unit to generate coherent light of which the intensity is greater than the absolute value of the minimum amplitude of the reproduced image, with the same phase as the reference phase within the reproduced image; an image sensor to receive an input image in pixel increments; and an optical system to guide the reference light to the hologram recording medium, and also guide the obtained reproduced image according to the irradiation of the reference light, and the coherent light to the image sensor.

Abstract: A hologram recorder records a hologram in a hologram recording medium by interference of a recording beam irradiated at a predetermined incident angle to the medium via a spatial light modulator incliningly in a predetermined direction with a reference beam irradiated incliningly in an opposite direction to the recording beam so that the beams crosses at a predetermined crossing angle. The recorder includes a beam modulator for converting a Gaussian-beam having a Gaussian-distribution of intensity into a parallel beam having an intensity distribution tending to be uniform and allowing the parallel beam to travel to the spatial modulator as the recording beam. The Gaussian-beam has a center axis decentered from an optical axis of the beam modulator in a decentering direction including a directional component of the predetermined direction in which the recording beam is inclined or an opposite directional component thereto.

Abstract: A hologram recording apparatus includes a laser light source for emitting laser light, a light splitter for splitting the laser light emitted from the laser light source into a signal beam and a reference beam, a light modulator for modulating the signal beam split by the light splitter, a phase modulator for phase-modulating the reference beam split by the light splitter, an optical system for collecting the signal beam modulated by the light modulator and the reference beam phase-modulated by the phase modulator onto almost the same collecting position on a hologram recording medium, a collecting-position control mechanism for controlling the collecting position along a surface of the hologram recording medium, and a distance control mechanism for controlling the distance between the phase modulator and the hologram recording medium.

Abstract: A hologram lens manufacturing apparatus includes: a separation unit that separates a light beam emitted from a light source into a reference light beam and an irradiation light beam; an irradiation light irradiating unit that collects the irradiation light beam so as to have a focal point at a predetermined focal position, and irradiates a hologram recording element located on the way to the focal point with the irradiation light beam; and a reference light irradiating unit that irradiates the hologram recording element with the reference light beam under a predetermined irradiation condition to record an interference pattern occurring between the irradiation light beam and the reference light beam as a hologram.

Abstract: The invention describes a collinear optical head for a reflection-type holographic recording medium, which is capable of obtaining an increased capacity. The optical head presented here allows for high capacity by combining holographic multiplexing methods, based on a shift and/or phase-coded reference beam, and/or scanned reference beam and/or angle and/or confocal addressing techniques. The parallel reading method and the format of the holographic recording medium ensure high-speed data transfer. Combined multiplexing is implemented in the system by means of a confocal optical arrangement that reduces crosstalk between adjacent holograms by filtering out object beams unintentionally reconstructed from non-addressed holograms.

Abstract: A method and apparatus for performing reproduction position servo-control without reducing the recording capacity of a holographic recording medium. Upon the reproduction of a holographic recording medium 18, part of a reproduction beam serving as a servo beam is projected onto a recording layer 18A of the holographic recording medium 18 from the side opposite to the side of the reproduction beam (a reference beam) along the same optical axis as that of the reproduction beam, and the diffraction beam thereof is detected by a photodetector 26C through a polarizing beam splitter 26B.

Abstract: The present invention provides one or more books of holograms recorded in a recording medium, wherein two or more short stacks of the one or more books have locations that differ from each other by a movement difference. The present invention also provides methods and devices for recording and reading holograms from the one or more books of holograms.

Abstract: A hologram information reproducing device is described which can reproduce information from a recording medium on which hologram information is recorded, and which can be downsized. In one aspect, when light from a light source is emitted, the light is converted into parallel reference light, by a lens of an optical system. A mirror changes the orientation of the reference light so that it is oriented obliquely downward towards a recording medium. More specifically, as viewed from the top, the mirror changes a path of the light from the light source unit by approximately 90 degrees. In addition, as viewed from the side, the mirror changes the path of the light from the light source unit downward by approximately 45 degrees. Since an interference pattern recorded on the recording medium is a Bragg grating, when the reference light illuminates a recording area of the recording medium, a reproduction light is obtained by Bragg diffraction.

Abstract: The hologram recording sheet according to the invention is made up of a base film and hologram sensitive materials sensitive to different wavelength regions formed therein in a desired pattern, or a film and at least two hologram recording sensitive materials sensitive to different wavelength regions laminated on the film with a transparent plastic spacer layer located therebetween, thereby enabling the required diffraction light wavelengths to be recorded on the required sites without producing unnecessary interference fringes. At least two hologram recording sensitive materials sensitive to different wavelength regions are formed on different sites on a film in dotted or striped configuration, the size of which is up to 200 mm or at least twice as large as the thickness of the sensitive material layers, thereby enabling regions diffracting light of different wavelengths to be formed in the form of independent sets of interference fringes.

Abstract: A display apparatus includes a display that displays individual images in a plurality of viewing directions on a common screen, a main body having a different chassis from that of the display, a display fan that cools down inside of the display, and a main body fan that cools down the inside of the main body.

Abstract: A holographic storage system records digital data to a holographic recording medium at recording locations that are strategically left open. A controller determines whether or not a predetermined event has occurred or a predetermined condition is present. If either the event occurs or the condition is present, the opened recording locations are closed. Subsequent data may be holographically recorded in open recorded locations as data appended to previously recorded data. The holographic storage system optionally includes an interim storage device. Controller may comprise a virtual storage controller.

Abstract: In the present invention, a volume holographic optical element is used as a pump coupler. The holographic coupler allows at least one pump wavelength to be coupled into the laser medium. The direction of the pump beam onto the coupler is not co-linear with the direction of the signal beam out of the coupler. The invention further provides the coupling of more than one pump wavelengths using a single holographic coupler element while maintaining the high isolation between pump and signal beam. The invention further provides a narrow-band reflection grating of various efficiencies for the signal beam (as part of the laser cavity).

Abstract: The pitch of light beam spots on a light receiving surface of an address detector upon search of information recorded on a holographic recording medium is decreased to reduce a distance between the holographic recording medium and the address detector. In a holographic recording and reproducing apparatus 10, a reference beam having an elliptical beam shape transformed by a beam shaping optical system 30 and an object beam having an unchanged circular shape are projected onto a holographic recording medium 20 so that interference fringes are allowed to be formed only within the elliptical shape. Therefore, even when the distance of an address detector 28 from the holographic recording medium 20 is reduced, crosstalk is prevented between array-shaped two-dimensional photodetectors 28A, 28B, 28C, and so on constituting the address detector 28.

Abstract: A method of holographically recording and reading information is disclosed. The method includes: recording information in a holographic recording medium by irradiating the holographic recording medium with a laser beam, wherein a transverse sectional area of the laser beam is divided into a central area for a signal beam and a ring-shaped area for a reference beam, the ring-shaped area surrounding the central area with a predetermined gap; and reading out the information from the holographic recording medium by irradiating the holographic recording medium with a ring-shaped readout beam having an area greater than that of the reference beam in at least one of directions inward of an inner diameter thereof and outward of an outer diameter thereof.

Abstract: A method of recording a plurality of holographic images in a holographic media, comprising recording a sequence of multiplexed holograms in a selected storage location in the holographic recording media, each hologram having a respective interbeam angle. The interbeam angle increases for each subsequently recorded hologram to compensate for a variable shrinkage of the holographic media during recording. The multiplexed holograms recorded at the selected storage location are partially or fully overlapped. During reading the recorded holograms, a reference beam is directed at a selected storage location in the holographic recording media at a sequence of incidence angles, each incidence angle being adjusted by a respective adjustment angle. The adjustment angles can be substantially equal.

Abstract: A multiplexed holographic recording apparatus of the present invention records multiplexed holograms in a plurality of recording regions that are formed on a holographic recording medium. In particular, the apparatus first records a predetermined number of multiplexed holograms in each of the recording regions formed in a predetermined range or an overall range of the holographic recording medium through holographic recording performed N times, and then performs the (N+1)th holographic recording in each recording region formed in the predetermined range or the overall range. When n other recording regions (where n=0, 1, 2, . . . ) are superimposed on each recording region formed on the holographic recording medium, a difference in the degree of multiplexing between the recording regions formed in the predetermined range or the overall range of the holographic recording medium does not exceed a predetermined value of n+1.

Abstract: An apparatus for writing and reading holograms, comprising a spatial light modulator (SLM) operable in phase mode, having a plurality of pixels for generating an object beam that overlaps with a reference beam; a holographic recording medium (HRM) in the path of the object beam; and a first lens element disposed in the path of the object beam between the SLM and the HRM; wherein the HRM is disposed at or near the Fourier transform plane of the first lens element.

Abstract: The hologram recording sheet according to the invention is made up of a base film and hologram sensitive materials sensitive to different wavelength regions formed therein in a desired pattern, or a film and at least two hologram recording sensitive materials sensitive to different wavelength regions laminated on the film with a transparent plastic spacer layer located therebetween, thereby enabling the required diffraction light wavelengths to be recorded on the required sites without producing unnecessary interference fringes. At least two hologram recording sensitive materials sensitive to different wavelength regions are formed on different sites on a film in dotted or striped configuration, the size of which is up to 200 mm or at least twice as large as the thickness of the sensitive material layers, thereby enabling regions diffracting light of different wavelengths to be formed in the form of independent sets of interference fringes.

Abstract: A holographic optical filter that includes an optical recording medium for storing several multiplexed reflection holograms that are formed by successive interference between two or more collimated object beams with a common collimated reference beam. The object beams are incident to the recording material at a series of angles chosen to provide reflection efficiency over the desired filed of view at the specified wavelength.

Abstract: A holographic recorder (A1) can vary the optical distance between an object lens (8) and a relay lens (7b) near the object lens (8). This arrangement allows defocus-multiplexing utilizing state variations in the laser beam when the beam reaches a storage medium (B1).

Abstract: An array of discrete sensors disposed on a substrate, each sensor comprising a holographic support medium and a hologram disposed throughout the volume of the medium, whereby interaction with an analyte results in a variation of a property of the medium.