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.

Abstract: A three dimensional display apparatus includes a diffraction panel for displaying a computer generated hologram and a look-up table. The look-up table includes a plurality of phase entries corresponding to a plurality of image points within a three dimensional image replay volume of the computer generated hologram. The apparatus further includes one or more processors configured to notionally divide the computer generated hologram into one or more hogels and to calculate diffraction fringe information for at least one of the hogels based on a selection of the phase entries.

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 variable optical phase modulator includes an array of movable, micro-electromechanical conductive plates. Each conductive plate has a substantially reflective surface, and is responsive to an applied voltage to move the conductive plate normal to a plane of the array to a predetermined distance with respect to other conductive plates in the array. The phase modulator also includes a voltage controller associated with the array of conductive plates. The voltage controller supplies a voltage to at least one of the movable conductive plates to move and position the movable plate to change the phase of electromagnetic energy reflected from the reflective surface with respect to the phase of electromagnetic energy reflected from other conductive plates in the array.

Abstract: An apparatus includes a light source configured to provide a path of light and a spatial light modulator located in the path of light and configured to modulate the light source. Relay optics are configured to receive the modulated light from the spatial light modulator and to project a computer generated image to a nominal image plane. The light source is configured to illuminate the spatial light modulator with collimated light.

Abstract: An original image (10), a recording surface (20), and a reference light (R) are defined and a large number of calculation points (Q(x, y)) are defined at a predetermined pitch on the recording surface (20). For each of the calculation points, intensity of interference wave, formed by an object light (O1 to ON) generated from the respective parts (P1 to PN) of the original image (10) and a reference light (R), is calculated. A binary pattern defined by dividing a unit area into a first area having a pixel value “white” and a second area having a pixel value “black” is defined in a plurality of ways by changing the occupancy ratio (0 to 100%) of the first area. A binary pattern having the occupancy ratio corresponding to the interference wave intensity calculated, is assigned to the position of the respective calculation points (Q) on the recording surface (20) so as to form a binary image and create a computer hologram medium having convex and concave portions.

Abstract: Apparatus and method for producing optically variable devices, optically variable media, dot matrix holograms or embossing substrates. The system includes: a laser beam generator, a laser beam shaper, a spatial light modulator, imaging optics and an image positioner. The laser beam generator generates a laser beam, which is shaped by the laser beam shaper to modify the laser beam to an optimized beam profile. The shaped laser beam is modulated by the spatial light modulator, which generates, at a place removed from the substrate surface, an optical pattern. The imaging optics causes the optical pattern to be imaged on the substrate surface. An image positioner allows for the optical pattern to be positioned to different areas of the substrate surface.

Abstract: There is provided a method of displaying a holographic image, the method comprises a number of steps. Three-dimensional object data is manipulated (802) that defines positions in a three-dimensional world space. A plurality of notional viewing locations are identified (803) that are compatible with notional eye-viewable positions. A two-dimensional image data set is produced (803) from the three-dimensional object data for each identified viewing location. The two-dimensional image data sets are processed (804) to produce phase-emphasised holographic data. The phase of a coherent light source is modulated (805) and the coherent light is directed to a viewer so as to be viewable at locations compatible with the eye-viewable locations.

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 method and apparatus is disclosed which can reproduce multi-value data with high reproducibility from a hologram recording medium having data recorded in multi-values therein and can reduce the error rate of reproduction data. A reference gradation pattern is recorded in a medium, and luminance unevenness of a gradation pattern obtained by reproducing the gradation pattern is corrected. A gamma characteristic of the medium is determined based on the reproduction gradation pattern, and a modulation pattern produced using easily separable luminance values determined based on the gamma characteristic is displayed on a spatial light modulator to record data in multi-values into the medium. Thereupon, the data are oversampled and recorded, and a block of the reproduced data is decoded depending upon a sequence of relative luminance levels of pixels in the block to decode the entire reproduced multi-value data.

Abstract: The invention provides an improved means for displaying computer generated hologram (CGH). Images appearing in the image volume are realised as a set of planar facets that approximate to the shape of the original object to be displayed. These facets are populated with points, that act as the visible parts of the displayed image. When an object is displayed, certain facets will not be face on the viewing zone. This will result in an apparent surplus of points on these facets, which is wasteful of computing effort. The current invention thus provides for certain facets to be denuded of points if these facets are not presented face on to the viewing zone of the CGH. The invention is mainly applicable for producing CGHs using the interference based algorithm, but can also be used in other types of 3D display that make up objects from an array of points.

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: The present invention relates to a method of producing digital holograms in a storage medium, in which the technical problem of writing computer-generated holograms by means of optical lithography as quickly as possible and with little effort with simultaneous accurate control of the timed triggering and the positioning of the write beam is achieved in that a write beam is focused onto the storage medium and moved one-dimensionally relative to the storage medium, in that a scanning beam is focused onto a trigger mask having a plurality of trigger lines and moved one-dimensionally transversely relative to the trigger lines, the movement of the scanning beam being coupled with the movement of the write beam, in that, during the scanning of the trigger lines, a timed trigger signal is generated as a function of the arrangement of the trigger lines, in that, with the aid of the timed trigger signal, the intensity of the write beam on the storage medium is controlled, and in that the hologram is written line by li

Abstract: A three-dimensional image display device is provided which allows a reduction in redundant calculation and high-speed obtainment of an optimum control image to be recorded on an optical wavefront control unit This invention relates to a three-dimensional image display device for displaying a three-dimensional image by irradiating illuminating light at an optical wavefront control unit which records a control image. The three-dimensional image display device of this invention includes a control image optimizing unit which calculates three-dimensional images corresponding to a group of control images based on constraints inherent to the optical wavefront control unit, selects a control image corresponding to a three-dimensional image satisfying a predetermined condition from the group of control images and records the selected control image on the optical wavefront control device.

Abstract: A holographic display comprises a spatial light modulator (SLM), a light source arranged to illuminate the SLM, and replay optics arranged to focus light reflected from the SLM to present a three dimensional image. The light source appears substantially at a zeroth order point of the replay optics, such that light from the light source is directed through the replay optics before illuminating the SLM.

Abstract: The invention relates to a hologram that enables two or more different images to be simultaneously reconstructed even in a state where the hologram is fixed in terms of relative position with respect to an eye, and a holographic viewing device that incorporates it. The hologram 14 is fabricated by applying Fourier transform to a plurality of input image to obtain a plurality of corresponding Fourier transform images 13-1, 13-2 and arraying the Fourier transform images 13-1, 13-2 on the same plane according to a given two-dimensional array principle into a computer-generated hologram. When a plurality of point light sources 231 to 239 located behind the hologram 14 are viewed through the hologram 14, a plurality of images are simultaneously and parallel reconstructed (28) in correspondence to the array positions of the plurality of Fourier transform images.

Abstract: The invention relates to a method for identifying articles, wherein article identification data are made available and the article is provided with a hologram representing said data so that the article can be identified by way of an intensity profile corresponding to said hologram. To this end, article-identifying individual data are provided, a hologram profile is digitally calculated using said individual data, and an intensity modulation of the hologram-producing beam is determined. The hologram-producing beam transfers the hologram pixels onto a hologram support that is associated with the article to be identified so that the article can be identified by way of the intensity profile reproduced from the associated hologram support.

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: A lithograph for producing digital holograms in a storage medium includes a light source for producing a write beam, the light source having drive means for the two-dimensional movement of the write beam relative to the storage medium and having a first objective for focusing the write beam onto the storage medium. Writing computer-generated holograms by means of optical lithography is solved in that: a two-dimensional trigger matrix is provided, means of producing a scanning beam are provided, a second objective for focusing the scanning beam onto the trigger matrix is provided, the drive means moves the scanning beam two-dimensionally relative to the surface of the trigger matrix, the movement of the scanning beam being coupled with the movement of the write beam, and means for generating a trigger signal to control the intensity of the write beam are connected to the trigger matrix.

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: A holographic display comprising a spatial light modulator, SLM, for displaying a computer generated hologram, CGH, containing horizontal or vertical parallax only, HPO, means for illuminating the SLM, and means for guiding light reflected from the SLM to a display region, the means for illuminating the SLM comprising a vertically/horizontally oriented line light source.

Abstract: An apparatus and method for demultiplexing multiple wavelengths of light. In one embodiment, an optical signal having a plurality of wavelengths is provided to an optical-to-electrical (OE) circuit configured to convert optical signals into electrical signals. The optical signal may include a plurality of wavelengths. The OE circuit converts the optical signal into a first electrical signal. The first electrical signal is received by a demodulating circuit, which also receives a demodulating signal. The demodulating circuit combines both the first electrical signal and the demodulating signal in order to produce a second electrical signal. Both the second electrical signal and the demodulating signal correspond to one of the wavelengths in the optical signal.

Abstract: The present invention is related to a compact microscope able to work in digital holography for obtaining high quality 3D images of samples, including fluorescent samples and relatively thick samples such as biological samples, said microscope comprising illumination means (1,41) at least partially spatially coherent for illuminating a sample (2) to be studied and a differential interferometer (5) for generating interfering beams from said sample (2) on the sensor (33) of an electronic imaging device (7), said interferometer (5) comprising namely tilting means (17) for tilting by a defined angle one the interfering beams (28 or 29) relatively to the other, said tilting resulting into a defined shift (27) of said interfering beam on the sensor of the electronic imaging device (7), said shift (27) being smaller than spatial coherence width of each beam, said microscope being able to be quasi totally preadjusted independently from the samples so that minimum additional adjustments are required for obtaining reli

Abstract: A holographic display comprises a spatial light modulator, SLM, arranged to display a set of tiled holographic images, and illuminating means for illuminating a surface of the SLM. Replay means are provided for focusing light reflected from the SLM surface to present a three dimensional image. The illuminating means comprises a light source appearing substantially at a DC spot position of the replay means.

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 small, inexpensive three-dimensional image display having a structure for displaying a color three-dimensional image sharply even if a low-resolution spatial optical modulating element is used. The three-dimensional image display has an illumination light source unit, a transmission spatial optical modulating element, a lens, and a mask. The illumination light source unit includes three point light sources outputting illumination light components having wavelengths (red, green, blue) different from one another. The point light source outputting the blue illumination light component of the shortest wavelength is disposed in position B(0, 0) on the optical axis of an illumination optical system, the point light source outputting the red illumination light component is disposed in position R(xr, 0), and the point light source outputting the green illumination light component is disposed in position G(xg, 0).

Abstract: A method for the calculation and storage of a computer-generated multilayer hologram with more than or equal to 2 holograms includes the following steps. Field AO of a readout beam and field AR in the reflection plane are preset as mathematical functions. Except for the hologram to be calculated, all the other holograms of the layer structure are also preset as mathematical functions. Fields A+/A? are then calculated on both sides of hologram hi, as a result of which hologram function hi, is calculated by forming a quotient from fields A+/A?.

Abstract: The invention relates to a hologram that enables two or more different images to be simultaneously reconstructed even in a state where the hologram is fixed in terms of relative position with respect to an eye, and a holographic viewing device that incorporates it. The hologram 14 is fabricated by applying Fourier transform to a plurality of input image to obtain a plurality of corresponding Fourier transform images 13-1, 13-2 and arraying the Fourier transform images 13-1, 13-2 on the same plane according to a given two-dimensional array principle into a computer-generated hologram. When a plurality of point light sources 231 to 239 located behind the hologram 14 are viewed through the hologram 14, a plurality of images are simultaneously and parallel reconstructed (28) in correspondence to the array positions of the plurality of Fourier transform images.

Abstract: A method of writing a spatially heterodyne hologram having spatially heterodyne fringes includes: passing a single write beam through a spatial light modulator that digitally modulates said single write beam; and focusing the single write beam at a focal plane of a lens to impose a holographic diffraction grating pattern on the photorefractive crystal, the holographic diffraction grating pattern including the spatially heterodyne hologram having spatially heterodyne fringes, wherein only said single write beam is incident on said photorefractive crystal without a reference beam.

Abstract: A method of displaying a computer generated hologram includes displaying the image as a set of facets that approximated to the true shape of the object to be displayed. Each of these facets is populated with points that together make up the image. The invention provides a number of array structures that allow adjoining facets at different orientations and angles to be populated with point without creating areas around the join of either point overpopulation or point underpopulation, and so results in a higher quality image. The invention is mainly applicable for producing interference base Computer Generated Holograms, but can also be used in other types of 3D display that make up objects from an array of points.

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

Abstract: A method for producing an active, real and three-dimensional image includes a three-dimensional region evenly spread with fluorescent agents, and a plurality of invisible lasers projecting in the three-dimensional region from different directions. The fluorescent agents positioned at a location focused by all of the invisible lasers are excited to generate fluorescence of visible wavelength. And, via rapidly scanning the invisible lasers in the three-dimensional region back and forth to cross at different locations, an active, real and three-dimensional image can be seen due to afterimage of eyes.

Abstract: The method consists of computing (E1-E4) a set of two-dimensional images in a three-dimensional geometrical space representing a virtual object from respective different viewpoints. The virtual object is represented by digital data stored in a computer. Holograms are computed (E5-E6) for the respective two-dimensional images using a fast complex transform, such as a Fourier transform. The holograms are then juxtaposed (E7) to form a digital hologram of the object which is physically reproduced (E8) by a spatial light modulator. A three-dimensional image of the object is obtained by illuminating the spatial light modulator with a coherent source.

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: The invention relates to a method for calculating a light field which propagates between a non planar surface of a computer-generated hologram and a planar reconstruction surface, in which an intermediate plane arranged in front of the hologram is defined, in which the propagation of the light field between the reconstruction plane and the intermediate plane is calculated by means of a transformation, and in which the propagation of the light field between the non-planar hologram surface and the intermediate plane is estimated. This method solves the technical problem of taking account of the geometrical distance differences that arise on account of unevennesses of the storage medium ill the calculation of the hologram function and the reconstruction or read-out and at the same time of specifying a fast algorithm. The invention also relates to a method for producing a hologram, storage medium and a device for reading out a hologram.

Abstract: A hologram recording method, which records signal light onto an optical recording medium as a hologram, includes: placing a signal light region, which generates signal light, and a reference light region, which generates reference light, symmetrically with respect to an optical axis of coherent light by displaying, on a spatial light modulator which spatially modulates the incident coherent light, a pattern which divides a modulating region into a plurality of regions; generating signal light and reference light by modulating the incident coherent light by the spatial light modulator; simultaneously and coaxially illuminating, onto a reflecting-type optical recording medium, the signal light and the reference light generated from the signal light region and the reference light region disposed symmetrically to one another; and recording the signal light on the optical recording medium as a hologram.

Abstract: A method of generating a Computer Generated Hologram (CGH) using the diffraction specific algorithm allows a curved wavefront to be produced from a single hogel, rather than the planar waves of the prior art. This allows a wavefront from a singel hogel to generate a point in the image volume. An imaginary wavefront is transmitted from each point in the image volume and sampled at a plurality of points over the hogel. These samples are used to produce a set of complex Fourier coefficients that can be used to approximate the original waveform.

Abstract: Methods and apparatus for making, encoding, and encrypting binary patterns for storing recorded information. One of the methods includes the steps of providing an original image, fragmenting the original image into at least two parts including a first part and a second part, forming a mirror image of one of the a least two parts, inverting the first and second parts, forming a binary pattern of the first part and the second part, and forming a mirror image of the binary pattern of the one of the a least two parts. In this method the binary pattern in each of the parts includes information representing a respective portion of the original image.

Abstract: Hologram production techniques can combine source data representing realistic information describing an environment with source data providing representational information describing a feature of the environment and/or some object interacting with the environment. The combined data is used to produce holograms, and particularly holographic stereograms including features that enhance the visualization of the environment depicted in hologram. A haptic interface can be used in conjunction with such holograms to further aid use of the hologram, and to provide an interface to secondary information provided by a computer and related to the images depicted in the hologram.

Abstract: A granular speck pattern is generated by a reflecting laser beam as an object to be measured is irradiated with a laser beam. This granular speck pattern is directly picked up as an image index by a line sensor. An A/D converter converts an analog signal supplied from the line sensor to a digital signal, and a processing unit calculates the amount of movement of the object on the basis of movement of a pixel interval of the granular speck pattern. A display device displays the amount of movement calculated by said processing unit.

Abstract: A method of generating a binary computer generated hologram for use in displaying a holographic image, the method comprising the steps of generating a complex modulation computer generated hologram corresponding to a desired reply object, transforming the complex modulation computer generated hologram into a real positive computer generated hologram, and transforming the real positive computer generated hologram into a binary computer generated hologram by comparing each element of the real positive computer generated hologram with at least one neighboring element and replacing the compared element with a binary value which depends upon the result of the comparison.

Abstract: To operate an optical device comprising an SLM with a two-dimensional array of controllable phase-modulating elements groups of individual phase-modulating elements are delineated, and control data selected from a store for each delineated group of phase-modulating elements. The selected control data are used to generate holograms at each group and one or both of the delineation of the groups and the selection of control data is/are varied. In this way upon illumination of the groups by light beams, light beams emergent from the groups are controllable independently of each other.

Abstract: The invention relates to a computer-generated hologram fabrication process that can reduce loads on computation of interference fringes for an original image including micro-characters. A visually perceivable original image 11 and a visually unperceivable original image 12 (micro-characters) are defined, and sample point sources of light P are defined at a low density on the original image 11 and at a high density on the original image 12. Interference fringes of object light coming from the point light sources on the original image 11 and reference light R are found on each computation point within an area ?1 on a recording surface 20, and interference fringes of object light coming from point light sources on the original image 12 and reference light R are found on each computation point within an area ?2 on the recording surface 20.

Abstract: Disclosed herein is a method, system and computer readable medium for a distortion-tolerant 3-D object recognition that may include recording a single exposure digital hologram of a 3D object on a sensor by on-axis digital holography; representing the recorded single exposure digital hologram mathematically as a synthesized hologram and as a reconstructed complex wave function of the 3D object; repeating the steps above for at least one comparison 3D object and obtaining a comparison reconstructed complex wave function of the comparison 3D object; and constructing a correlation filter for 3D distortion-tolerant object recognition from the reconstructed complex wave function of the 3D object and from the at least one comparison reconstructed complex wave function of the comparison 3D object also recorded; and correlating the reconstructed complex wave function of the 3D object to the comparison reconstructed complex wave function of the comparison 3D object using the correlation filter in order to recognize 3D

Abstract: An apparatus for detecting a hidden image, which is formed in a first area of a hologram, is disclosed. The apparatus has a laser device for generating a laser beam and projecting the laser beam to the hologram, and a sensing device for sensing light that reflects from the hologram. When the laser beam is emitted to the hologram at a first incident angle, at least one diffractive beam is generated by diffraction of the laser beam. The sensing device is capable of outputting a responding signal according to the characteristics of the diffractive beam. Additionally, if the laser beam is emitted to the hologram at an incident angle, which is not equal to the first incident angle, the diffractive beam cannot be generated so that the sensing device does not output the responding signal.

Abstract: A computer-generated hologram comprising a plurality of cells. The hologram has information recorded therein, the information operable to recreate a stereoscopic image of an object. At least one of said plurality of cells Pj has information related to a luminance TWLci (?XY, ?YZ) of a virtual point light source Qi from a plurality of virtual point light sources. The luminance corresponds to a point S on the object. The point S is on a straight line between said one of the plurality of cells Pi and the virtual point light source Qi.

Abstract: The invention provides a computer-generated hologram which can be viewed in white at the desired viewing region and a reflective liquid crystal display using the same as a reflector. The computer-generated hologram H is designed to diffuse light having a given reference wavelength ?STD and incident thereon at a given angle of incidence ? in a specific angle range. In a range of wavelengths ?MIN to ?MAX including the reference wavelength ?STD wherein zero-order transmission light or zero-order reflection light of incident light on the computer-generated hologram at a given angle of incidence is seen in white by additive color mixing, the maximum diffraction angle ?2MIN of incident light of the minimum wavelength ?MIN in the wavelength range and incident at the angle of incidence ? is larger than the minimum diffraction angle ?1MAX of incident light of the maximum wavelength ?MAX in the wavelength range and incident at said angle of incidence ?.

Abstract: A computer-generated hologram fabrication process which reduces loads on computation of interference fringes for an original image including micro-characters. A visually perceivable original image and a visually unperceivable original image (micro-characters) are defined, and sample point sources of light are defined at a low density on the original image and at a high density on the original image. Interference fringes of object light are found on each computation point within a first area on a recording surface, and interference fringes of object light are found on each computation point within a second area on the recording surface. The light sources that become samples are defined at a given pitch on sectional lines obtained by cutting the original images 11 and 12 by a multiplicity of sections (parallel with an XZ plane) located at a given spacing. The section-to-section spacing for the original image 12 is made narrows than that for the original image 11.

Abstract: Characterization of hologram elements (hogels) produced using specially designed test pattern images provides more accurate information that can be used to render images for use in hogel production. Once a test pattern is selected, one or more hogels are recorded in a holographic recording material using a spatial light modulator displaying the test pattern image. Recorded hogels can then be played back to produce an image of the test pattern. Characterization of this image yields information that is used to select angles used to render oblique parallel projections of a computer graphics scene. The rendered projections are then used to record hogels that will produce images with reduced distortion.

Abstract: This invention pertains to the design of optimized far field viewing devices that simultaneously produce bright far field holographic light patterns and achieve good see-through performance to present a well focused scene. A far field transmission hologram recorded on a transparent substrate has regions having high diffraction efficiency juxtaposed with regions having low diffraction efficiency. The high diffraction efficiency regions contribute to production of bright far field holographic light patterns, whereas the low diffraction efficiency regions contribute to see-through performance.