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: An electroholographic display system (300, 700) includes: a coherent light source (330, 730); a spatial light modulator (SLM) (320, 720) that modulates a coherent collimated light beam; and a processor and driver unit (310, 710) that generates hologram data and applies appropriate voltages to the pixels of the SLM to modulate the coherent collimated light beam with the hologram data and to suppress a zeroth order component of the modulated light beam at an image plane where the holographic image is reproduced. The processor and driver unit suppresses the zeroth order component of the modulated light beam by selecting the voltages to apply to the pixels of the SLM to cause a first group of pixels to provide a phase shift of 180 degrees to first portions of the collimated light beam with respect to portions of the collimated light beam modulated by a second group of pixels.

Abstract: A computer generated hologram includes a plurality of cells which form a light intensity distribution on a predetermined plane. The plurality of cells includes a plurality of first cells including isotropic media and anisotropic media, and a plurality of second cells including anisotropic media alone. The plurality of cells change a phase of incident light which impinges on each of the plurality of cells to form a phase distribution including N phases (N is the number of phases, N?2) for each of a wavefront of a linearly polarized light component in a first direction and a wavefront of a linearly polarized light component in a second direction perpendicular to the first direction.

Abstract: The present invention relates to a wavelength conversion laser system and provides a wavelength conversion laser system including a semiconductor optical amplifier, an optical condenser that condenses light emitted from the optical amplifier, a diffraction grating plate that induces wavelength components of the light having passed through the optical condenser in different directions, and an optical very large scale integration (VLSI) processor.

Abstract: A wavelength-tunable laser system includes an optical fiber collimator array having at least two ports, an optical amplifier connected to one port of an optical fiber, an optical coupler for coupling light incident from the optical amplifier and transmitting the coupled light to another port, a diffraction grating plate for guiding each wavelength component of light incident from the optical fiber collimator array in a different direction, and an Opto-Very Large Scale Integration (Opto-VLSI) processor.

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: The invention relates to video holograms and devices for reconstructing video holograms, comprising an optical system having a light source, lens and the video hologram having cells arranged in a matrix or a regular pattern with at least one opening per cell, the phase or amplitude of said opening being controllable. The holographic video representations of expanded spatial objects can be achieved in a wide viewing area in real time using controllable displays, whereby the objects are either computer-generated or created by different means. The space-bandwidth product (SBP) of the hologram is thus reduced to a minimum and the periodicity interval of the Fourier spectrum is used as a viewing window on the inverse transformation plane, through which the object is visible in the preceding space. The mobility of the viewer(s) is achieved by tracking the viewing window.

Abstract: A holographic three-dimensional (3D) image generating apparatus that may use a collimated directional blacklight unit (CD BLU) is provided. The CD BLU may output a collimated light of which an emitting light is adjusted. The convergent lens may enable the outputted collimated light to converge into a viewing area of a viewer and thus, a viewing window may be generated. A spatial light modulator (SLM) may perform spatially-varying modulation with respect to the collimated light converging into the viewing area to generate a focused beam.

Abstract: A method of forming an image comprising providing a device for imparting respective phase shifts to different regions of an incident wavefront, wherein the phase shifts give rise to an image in a replay field, and causing zero-order light to be focused into a region between the replay field and the device.

Abstract: An apparatus includes a recording light source configured to emit recording beams, an electrically addressable spatial light modulator (EASLM) configured to time sequentially modulate the recording beams emitted from the recording light source according to hologram information corresponding to a 3-dimensional image spatially divided into a plurality of portions, an optically addressable spatial light modulator (OASLM) configured to include a plurality of regions corresponding to the plurality of the divided portions of the 3-dimensional image and images on a region corresponding to the portions using the modulated recording beams to form a hologram, a scanning optical unit configured to reproduce the hologram formed by the recording beams serially modulated by the EASLM on a reduced scale and transmit the hologram to the regions of the OASLM corresponding to the portions, and a reproducing light source configured to produce a surface light and emit the surface light to the OASLM.

Abstract: Methods and apparatus for reconstructing a wave, including interpolation and extrapolation of the phase and amplitude distributions, with application to imaging apparatus, such as microscopes.

Abstract: A holographic image projection system for projecting an image at an acute angle onto a surface includes: a spatial light modulator (SLM) to display a hologram; an illumination system to illuminate the displayed hologram; projection optics to project light from the illuminated displayed hologram onto the surface at an acute angle form the image; and a processor having an input to receive input image data for display and an output to provide hologram data for the SLM, wherein the processor is configured to: input image data and convert this to target image data; generate from the target image data hologram data for display as a hologram on the SLM to reproduce a target image; and wherein the target image is distorted to compensate for the projection of the hologram at an acute angle to form the image.

Abstract: A holographic display device comprises a first OLED array writing onto a first OASLM, the first OLED array and the first OASLM forming adjacent layers, and a second OLED array writing onto a second OASLM, the second OLED array and the second OASLM forming adjacent layers. The first and the second OASLMs encode a hologram and a holographic reconstruction is generated by the device when an array of read beams illuminates the first and second OASLMs and the first and second OASLMs are suitably controlled by the first and second OLED arrays. Advantages include that this device permits independent control of phase and amplitude, and the device lends itself to compactness.

Abstract: Dynamically reconfigurable holograms with electronically erasable programmable intermediate layers are disclosed. An example apparatus includes first nanowires, each of the first nanowires having protuberances along a length thereof. The example apparatus also includes second nanowires arranged approximately perpendicular to the first nanowires, the protuberances of the first nanowires being approximately parallel to corresponding ones of the second nanowires. In addition, a layer is disposed between the first and second nanowires. The layer is to control refractive indices at nanowire intersections at intersecting ones of the first and second nanowires.

Abstract: A card authentication is performed. An authentication chip for performing authentication by a copy-disabled hologram chip is attached to a card and when or after the card is introduced into a handling device, the authentication chip information is read to perform authentication. Read may be performed in a planar shape but a linear shape can reduce the processing load. An arbitrary straight line or a curved line may be used as a read line shape by modifying the read position in association with the card movement when the card is placed to be read. When the card introduced to a terminal device is an unauthorized one, the card is ejected or an alarm is issued when the card is introduced inside.

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: A cooling device which prevents ambient persons from being exposed to an unpleasant feeling as much as possible by properly controlling an exhausting direction of the air which is used for cooling and exhausted from a chassis and an image projection apparatus having the cooling device are obtained. The cooing device cools first and second members to be cooled provided in the chassis, has first and second exhaust fans for guiding winds which have cooled the respective first and second members to an outside of the chassis, and is characterized in that the first and second exhaust fans are arranged so as to face the same surface of the chassis and the winds exhausted from the first and second exhaust fans are mixed.

Abstract: A method and system for manipulating object using a three dimensional optical trap configuration. By use of selected hologram on optical strap can be configured as a preselected three dimensional configuration for a variety of complex uses. The system can include various optical train components, such as partially transmissive mirrors and Keplerian telescope components to provide advantageously three dimensional optical traps.

Abstract: Systems, methods, and devices that generate and display a holographic image(s) of a 3-D real or synthetic object scene are presented. A holographic generator component (HGC) partitions a 3-D object scene into a horizontal stack of regularly spaced vertical sub-planes that are each contributed to a respective sub-line. The HGC converts the sequence of sub-lines into a collection of diffraction patterns, which are summed up and interfered with a reference beam to generate the complete hologram, which can be or can approximate a Fresnel hologram. A multi-rate filter is employed to facilitate converting sub-lines to diffraction patterns more quickly. The multi-rate filtering can be realized using convolution in the spatial domain, realized in the frequency domain using a fast Fourier transform, and/or realized in the frequency domain using a graphic processing unit.

Abstract: Hologram recording medium is manufactured by using computer. On a recording plane 20, cell position points Q are defined at a pitch Ph along the cell position lines f(i) which are arranged on the recording plane 20 at a pitch Pv. For each individual cell position point Q, an amplitude A and a phase ? of a synthetic wave of object light components emitted from a plurality of sample points on an associated image contour are determined by computation. At each individual cell position point Q, is positioned a three-dimensional cell C, having a diffraction grating G, with a phase that is in accordance with the phase ?, formed in an effective region E having an area that is in accordance with the amplitude A. The diffraction grating G is formed by periodically positioning staircase steps with a period ?. With the three-dimensional cell C, a length Cv is set to. 20 ?m, a width Ch is set to 0.4 ?m, and the period is set to approximately 1 ?m.

Abstract: A method and a device for manufacturing a hologram recording medium that has an arrangement by which different original images are reproduced when observed from different positions. The method includes preparing a plurality of original images, setting a predetermined recording plane, setting a predetermined reference light, setting a plurality of observation regions, computing an interference fringe pattern, and forming the interference fringe pattern on a physical medium. When computing an interference fringe pattern, computations of only the light components of each original image which would reach the respective observation region are performed.

Abstract: A technique for fabricating a highlight hologram based on a digital object performs point sampling on the object and represents each sampled point as a geometric patch. A set of geometric patches corresponding to sampled points from the object are fabricated into a substrate. A paraboloid patch may be used for reflective substrates while a hyperboloid may be used for transmissive substrates. To avoid specifying overlapping patches, which are impractical to fabricate, certain of the sample points may be merged. An output set of grooves is saved and may be used to specify fabrication of a highlight hologram on the physical substrate.

Abstract: We describe a method of determining an aberration correction for a holographic image display system using a spatial light modulator (SLM) to display a hologram. Embodiments of the invention measure the corrections needed for a particular projection system, using the same system SLM as used to generate the images to provide wavefront-sensing holograms. The projector's projection optics are used to provide the wavefront sensor and there is no need for lenslets. Embodiments of the invention use a plurality of successive holograms directing light from differently-located patches on the hologram into the image.

Abstract: We describe optical techniques for replicating an image to expand the exit pupil of a head-up laser-based image display system. The system includes image replication optics to replicate an image carried by a substantially collimated beam, the image replication optics comprising a pair of substantially planar reflecting optical surfaces defining substantially parallel planes spaced apart in a direction perpendicular to the parallel planes. The system is configured to launch the collimated beam into a region between the parallel planes such that the reflecting optical surfaces waveguide the beam between the surfaces in a plurality of successive reflections at front and rear optical surfaces. The front optical surface is configured to transmit a proportion of the collimated beam when reflecting the beam such that at each reflection of the collimated beam at the front optical surface a replica of the image is output from the image replication optics.

Abstract: A modular routing node includes a single input port and a plurality of output ports. The modular routing node is arranged to produce a plurality of different deflections and uses small adjustments to compensate for wavelength differences and alignment tolerances in an optical system. An optical device is arranged to receive a multiplex of many optical signals at different wavelengths, to separate the optical signals into at least two groups, and to process at least one of the groups adaptively.

Abstract: A method of retrieving phase information from input intensity information, representative of a target image, in which a Fourier transform is performed on data and the result used in forming a phase estimate, the phase estimate being inverse Fourier transformed, thereby producing magnitude and phase replay, and wherein not only is the phase reply component but also data derived from the magnitude replay component, iteratively fed back.

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: A method of calculating a computer generated hologram (CGH) using a look-up table and an apparatus thereof are disclosed. The method in accordance with an embodiment of the present invention can include calculating one principal fringe pattern for points of a target object that are separated by a same distance from a reference point of a hologram plane, writing the principal fringe pattern in the look-up table in accordance with a distance between the points of the target object and the reference point, calculating computer-generated hologram information by shifting the principal fringe pattern to the points of the target object located on a same plane, and playing back a three-dimensional image by using the computer-generated hologram information.

Abstract: A method of computing CGH using look-up table and temporal redundancy and an apparatus thereof are disclosed. The apparatus includes an extracting unit, which extracts a brightness image and a depth image from a target frame of 3D video, a comparing unit, which extracts a change point that is different from a point of the target frame after comparing the brightness image and the depth image of the target frame to a brightness image and a depth image of a previous frame, a hologram computing unit, which computes hologram information by differentiating hologram computing methods using hologram patterns depending on whether a ratio between the number of the change points and the number of the entire frame points is equal to or greater than a predetermined critical value, and a storing unit, which stores the brightness image and the depth image of the target image and the hologram information.

Abstract: A method of computing a computer generated hologram (CGH) using a look-up table and spatial redundancy and an apparatus thereof are disclosed. The method in accordance with an embodiment of the present invention can includes computing one principal fringe pattern for each point of a target object that is separated by a same distance from a reference point of a hologram plane, storing the principal fringe pattern in accordance with a distance between each point of the target object and the reference point, computing identity data representing whether each point of an input image and adjacent points are identical to one another, computing an n-point fringe pattern by combining n principal fringe patterns and computing hologram information by matching the n-point fringe pattern to n successive points identified from the identity data. Here, the n is a natural number.

Abstract: A method of computing a hologram for reconstructing an object using a display device is provided. The display device enables a holographic reconstruction of the object. The display device comprises a light source and an optical system to illuminate a hologram-bearing medium being encodable with the hologram. The method comprises the steps of: (a) computing the hologram by determining the wavefronts at an approximate observer eye position that would be generated by a real version of the object to be reconstructed; and (b) encoding the computed hologram in the hologram-bearing medium.

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: The invention relates to a method of and apparatus for displaying a holographically generated video image having plural video frames. For each frame there is provided and computed (20) a respective sequential plurality of holograms. Each said sequential plurality of holograms of the plural video frames are sequentially displayed on a diffractive element (12) for viewing the replay field thereof, and the noise variance of each frame is perceived as attenuated by averaging across said plurality of holograms.

Abstract: A continuous scanning method employs one or more moveable sensors and one or more reference sensors deployed in the environment around a test subject. Each sensor is configured to sense an attribute of the test subject (e.g., sound energy, infrared energy, etc.) while continuously moving along a path and recording the sensed attribute, the position, and the orientation of each of the moveable sensors and each of the reference sensors. The system then constructs a set of transfer functions corresponding to points in space between the moveable sensors, wherein each of the transfer functions relates the test data of the moveable sensors to the test data of the reference sensors. In this way, a graphical representation of the attribute in the vicinity of test subject can be produced.

Abstract: Two original images to be recorded are prepared as data (S10). A plurality of unit regions, each having an adequate area to record interference fringes of visible light, are defined and positioned on a hologram recording surface (S20). A gradation pattern, with which appearance probabilities of two record attributes gradually change in space, is overlapped onto the recording surface, and to each unit region, one of either record attributes is assigned according to the appearance probabilities of the respective record attributes at each individual position (S30).

Abstract: Provided is a hologram-image projection method including a step of setting three-dimensional position information in a specimen for a plurality of focal points where laser light is to be focused via an objective lens; a step of performing reverse ray tracing from the individual focal points to an entrance pupil position of the objective lens by using the position information set for the individual focal points in the specimen, a refractive index of the specimen, and overall characteristic data of the objective lens, to calculate a wavefront of the laser light at the entrance pupil position from the individual focal points; a step of calculating a combined wavefront by combining the plurality of calculated wavefronts; a step of setting a phase pattern to be applied to a wavefront modulating device on the basis of the calculated combined wavefront; and a step of applying the set phase pattern to the wavefront modulating device, causing the laser light to be incident thereon, and focusing the laser light whose w

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: To compensate for an inhomogeneous brightness perception in a holographic reconstruction of 3D-scenes (4), a computing means encodes modulator cells of a SLM with a hologram point data pattern. Multiple bundles of rays illuminate the surface of the SLM and an array of focusing elements (21, 23) directs the bundles of rays to an observer's eye positions. Geometrical and optical properties of the array cause dissimilarly affected illumination regions on the SLM surface. The computing means determine parameters which describe the extent of these effects in combination with an expected spatial filtering at the eye pupil of the observer's eyes. Using these parameters, the computing means estimates which local errors of the reconstruction caused by these dissimilarly affected illumination regions will be perceived by the observer when watching the reconstruction, and corrects the hologram point data pattern such that the reconstruction appears at a corrected brightness uniformity level.

Abstract: An optical element having a set of a plurality of three dimensional cells. Each cell with a specific amplitude and a specific phase are defined and which has optical characteristics such that when a predetermined incident light is provided to the individual cell, an emitted light, resulting from changing the amplitude and the phase of the incident light in accordance with the specific amplitude and the specific phase defined for the cell is obtained.

Abstract: Video image data is converted into spatial frequency information using Fourier transformation. The spatial frequency information is provided to an information display unit. The spatial frequency information as a phase distribution is displayed on the information display unit, light is irradiated onto the information display unit using a light source, and the amount of light that is irradiated by the light source is adjusted based on the video image data. And diffraction light, which is irradiated by the light source and modulated as the spatial frequency information by the information display unit, is projected onto a projecting unit.

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 video holographic display device operates so that the size of a reconstructed three dimensional scene is a function of the size of the hologram-bearing medium; the reconstructed three dimensional scene can then be anywhere within a volume defined by the hologram-bearing medium and a virtual observer window through which the reconstructed three dimensional scene must be viewed. This contrasts with conventional holograms, in which the size of the reconstructed scene is localised to a far smaller volume and is not a function of the size of the hologram-bearing medium at all.

Abstract: A numerical method of recording a two or three dimensional object scene in a binary hologram. When the binary hologram is illuminated with a reference beam, the original object scene can be reconstructed and observed by a viewer. As the hologram is binary, i.e. composed of black or white pixels, it can be printed with commodity printers. The process is simple, fast, and economical, hence decreasing the cost and time for hologram design and production. In addition, with binary holograms, the ability to store the holograms is enhanced and binary holograms facilitate efficient transmission of the holograms.

Abstract: An optical wavefront control pattern generating apparatus (1) relating to the present invention includes: a target image detector unit (60) configured to detect spatial information of the object (B) as a target image; a reconstructed image detector unit (40) configured to detect the reconstructed image displayed on the reconstructed image display unit (30); and an optimizer unit (50) configured to evaluate, on the basis of the target image detected by the target image detector unit (40), the reconstructed image detected by the reconstructed image detector unit (40), and to apply a modification process to the optical wavefront control pattern in a way that a result of the evaluation satisfies a predetermined condition, so as to generate the optimum optical wavefront control pattern.

Abstract: A diffractive coupling element based on a computer-generated hologram is used in an optical coupling system of a transmitter to control the launch of laser light from a laser light source onto an end of an optical fiber. The diffractive coupling element controls the launch of the laser light such that a desired optical intensity distribution pattern is provided that substantially avoids the center and edge refractive index defects contained in the optical fiber.

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: There is provided a light source unit which includes a luminescent light source which receives excitation light so as to emit light of a predetermined wavelength band, excitation light sources which shine excitation light on to the luminescent light source, a reflection space having the luminescent light source in an interior thereof and an emission space which emits luminescent light source light emitted from the reflection space from an emission port whose area is made smaller than the area of the luminescent light source and a projector which employs the light source unit.

Abstract: Arrangements are made to enable different original images to be reproduced upon observation from different positions and yet enable reproduced images of high resolution to be obtained. In a case of recording two original images, each of the two original images Ia and Ib is defined as a set of point light sources in an XYZ global coordinate system, and two propagation spaces Sa and Sb, each enabling propagation of light emitted from an origin Q of an ??? local coordinate system, are defined. A predetermined recording plane and a reference light are set in the XYZ coordinate system, and an interference fringe pattern, which is formed on the recording plane by object light components from the point light sources constituting the respective original images and the reference light, is determined by computation.

Abstract: A method for influencing electromagnetic radiation in a frequency range between 0.1 and 10 terahertz includes providing a planar modulator having a matrix of at least 10×10 individual, active planar elements. Each planar element has a diameter between 5 ?m and 100 ?m. The planar elements are individually controlled using a central control unit such that each planar element assumes a respective one of at least two states in accordance with the control so as to influence the radiation.

Abstract: A method of computing a computer generated hologram (CGH) for use in displaying a holographic image of a replay object. The method of generating a first computer generated hologram corresponding to the desired replay object (step 1); subdividing the first computer generated hologram into a plurality of blocks, each representing a sub CGH (step 2); for each block or sub CGH, calculating the corresponding replay sub-image hereafter called target wavefront data set (step 3); and generating for each target wavefront data set a second constrained modulation computer generated hologram wherein that second CGH is modulated within constrained values (step 5); and combining the plurality of second constrained modulation computer generated holograms to provide a third complete constrained modulation computer generated hologram (step 6).