Abstract: A holographic memory system includes a light source for generating a reference beam having a wavelength; and a photodetecting device for selectively detecting a reconstructed signal beam corresponding to the reference beam. The photodetecting device includes a band-pass filter for transmitting light of a wavelength band including the wavelength of the reconstructed signal beam while blocking light having a wavelength deviating from the wavelength band; and a photodetecting unit for detecting the light transmitted through the band-pass filter.

Abstract: In an apparatus for detecting holographic data reproduced from a holographic medium, the holographic medium has an interference pattern and the holographic data is reproduced when a first portion of a reference beam is diffracted by the interference pattern within the holographic medium. A transmission beam detector detects a light intensity of a transmission beam which is a second portion of the reference beam, wherein the transmission beam is not diffracted to reproduce the holographic data and passes through the holographic medium. Then, a CCD (charge coupled device) controller generates a driving signal in accordance with the detected light intensity. Thereafter, a CCD detects the holographic data in response to the driving signal.

Abstract: An optical member 7 is bonded, at its rear side 7b, to a holographic stereogram 6. The front side 7a of the optical member 7 consists of parallel triangular prisms. Illumination light 9 is applied to the front surface 7a of the optical member 7 at a predetermined angle of, for example, 60°. The optical member 7 is made of, for example, optical glass or transparent plastic. Each triangular prism has an incidence surface 8, to which the illumination light is applied at right angles. The illumination light is applied to the interface 22 between the optical member 7 and the holographic stereogram 6, at an incidence angle ? of, for example, 60°, thereby to suppress surface reflection of the illumination light 9 at the interface 22.

Abstract: An optical member 7 is bonded, at its rear side 7b, to a holographic stereogram 6. The front side 7a of the optical member 7 consists of parallel triangular prisms. Illumination light 9 is applied to the front surface 7a of the optical member 7 at a predetermined angle of, for example, 60°. The optical member 7 is made of, for example, optical glass or transparent plastic. Each triangular prism has an incidence surface 8, to which the illumination light is applied at right angles. The illumination light is applied to the interface 22 between the optical member 7 and the holographic stereogram 6, at an incidence angle ? of, for example, 60°, thereby to suppress surface reflection of the illumination light 9 at the interface 22.

Abstract: An optical member 7 is bonded, at its rear side 7b, to a holographic stereogram 6. The front side 7a of the optical member 7 consists of parallel triangular prisms. Illumination light 9 is applied to the front surface 7a of the optical member 7 at a predetermined angle of, for example, 60°. The optical member 7 is made of, for example, optical glass or transparent plastic. Each triangular prism has an incidence surface 8, to which the illumination light is applied at right angles. The illumination light is applied to the interface 22 between the optical member 7 and the holographic stereogram 6, at an incidence angle ? of, for example, 60°, thereby to suppress surface reflection of the illumination light 9 at the interface 22.

Abstract: The invention relates to a holographic viewing device that enables a given pattern to be properly viewed in place of light sources in a scene and is easy to fabricate and assemble with consistent characteristics, and a computer-generated hologram for the same. The invention provides a holographic viewing device in which computer-generated holograms 2 and 3 each constructed as a transmission Fourier transform hologram is fitted in a frame member 1. At least one of phase information and amplitude information recorded in a certain predetermined peripheral site of the computer-generated hologram 2, 3 relative to an input pattern reconstructible from the computer-generated hologram is removed.

Abstract: A hologram screen 1 displays an image by diffracting and scattering image light 31 projected from an image projection apparatus 2. An upward/downward light scattering device 13, which scatters light incident from an upward/downward specific angle range spreading obliquely upward or downward, is placed on the image projection apparatus side of a hologram device 12 in the hologram screen 1. A leftward/rightward light scattering device 14, which scatters light incident from a leftward/rightward specific angle range spreading obliquely leftward and rightward, is placed between the hologram device 12 and the scattering device 13. The construction is such that the upward/downward specific angle range contains the incidence angle of the image light 31 on the hologram screen 1, and thus provides a hologram screen having good color reproducibility and which permits viewing of the background.

Abstract: The present invention is related to a method for performing digital holographic imaging (DHI), said DHI being characterized by the fact that images of a sample are obtained by applying numerical means to reconstruct holograms of the sample. In the method of the invention, the sample is in a medium with controlled properties that influence the behaviour of the sample, and/or that influence the process of hologram formation. The information content of one hologram, or of a plurality of holograms, recorded with the sample in one medium, or in a plurality of medium, is used to reconstruct one image of the sample, or a plurality of images of the sample, that describe quantitatively one property of the sample, or a plurality of properties of the sample. The present invention is also related to an apparatus with which to perform said method.

Abstract: A holographic imaging system and method includes a radiation source for generating radiation. A data base has a set of elements, each element is indicative of a trajectory of a light ray exiting a point in a recorded scene. A spatial light modulator is receptive of the radiation from the radiation source and the elements of the data base mapped to the spatial light modulator, thereby projecting from the spatial light modulator an optical signal in the nature of a two dimensional bitmap of the recorded scene. A diffractive optical element includes a set of basis fringes receptive of the projected optical signal from the spatial light modulator for diffracting the optical signal in a specified direction. A multiplexer is receptive of the elements of the data base for multiplexing the elements of the data base to the spatial light modulator. A timing device synchronizes multiplexing the elements of the data base to the spatial light modulator and diffracting the optical signal in a specified direction.

Abstract: A holographic screen for displaying images by diffracting and dispersing an image beam projected by an image projector comprises a main hologram for diffracting and dispersing an incident image beam from one of an upward angle and a downward angle, and a directional dispersion hologram, disposed on an image projector side of the main hologram, for dispersing and transmitting part of the image beam within a predetermined angle range centered on a direction of incidence thereof, and directly transmitting another part of the image beam, thereby providing a holographic screen that can maintain the brightness and improve the color reproducibility of a displayed image.

Abstract: An optical member 7 is bonded, at its rear side 7b, to a holographic stereogram 6. The front side 7a of the optical member 7 consists of parallel triangular prisms. Illumination light 9 is applied to the front surface 7a of the optical member 7 at a predetermined angle of, for example, 60°. The optical member 7 is made of for example, optical glass or transparent plastic. Each triangular prism has an incidence surface 8, to which the illumination light is applied at right angles. The illumination light is applied to the interface 22 between the optical member 7 and the holographic stereogram 6, at an incidence angle ? of, for example, 60°, thereby to suppress surface reflection of the illumination light 9 at the interface 22.

Abstract: An optical device for security and anti-counterfeit applications comprises a diffractive structure comprising a discrete region that in response to white light illumination generates an image by a process of diffraction in close angular proximity to the specular reflection and which is thus substantially non-visible to an observer, and which under coherent illumination generates a laser projection covert image which forms an image in an image plane located away from the physical plane of the device and which is angularly co-located in close proximity to the direction and position of the specular reflection.

Abstract: This invention discloses a method of producing, in a solid transparent material (3), a hologram of an object; the method includes the steps of: developing a three-dimensional mathematical model of an electro-magnetic field emanating from the object, the field producing an image of the object; computing a corresponding three-dimensional set of points, light scattered from which reconstructs the field; and focusing a pulsed laser beam into the solid transparent material onto each of the points sequentially, the beam being capable, when focused, of causing optical breakdown in the solid transparent material.

Abstract: In a hologram recording method for forming a plurality of areas of a refractive index light interference pattern of a coherent signal light beam in accordance with information data within a recording medium having a shape of parallel flat plates, the signal light beam and the recording reference light beam cross each other within the recording medium, and a gate light beam having a second wavelength for revealing recording sensitivity of the recording medium is simultaneously irradiated to the recording medium so as to pass through a portion of the recording reference light beam and demarcate a volume smaller than that of this crossing portion.

Abstract: Angle of incidence of reproducing light with respect to a hologram or a holographic stereogram is adjusted so that a reproduced image can be repetitively viewed without requiring the viewer to move his or her viewpoint. The components of the image reproducing apparatus can be roughly classified into a power supply unit equipped with a power supply for generating a driving power and various types of electric circuits, a light source unit equipped with light emitting diodes and the like, a supporting unit for supporting the light source unit, and a holographic stereogram display unit for holding the holographic stereogram and displaying an image. In this image reproducing apparatus, the light source unit is swingably or turnably moved repetitively with respect to the holographic stereogram so that the reproducing light has angle of incidence changed on the holographic stereogram, thus allowing change of viewed image.

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: A system for recording and reading out holograms in a storage medium including a pattern encoder, a first fourier transform lens with a focal length f1, a second fourier transform lens with a focal length f2, a detector array, and a first and second prism. The first prism is located between the pattern encoder and the first fourier transform lens, wherein the optical length between the pattern encoder and the first fourier transform lens through the first prism is equal to a back focal length BFL1. The second prism located between the second fourier transform lens f2 and the detector array, wherein the optical path length between the second fourier transform lens and the detector array through the second prism is equal to a back focal length BFL2.

Abstract: The invention relates to a holographic viewing device that has a high diffraction efficiency, enables bright patterns with less noticeable conjugate or higher-order images to be viewed in place of light sources in a scene and is easy to fabricate with consistent characteristics. The holographic viewing device comprises a frame and a computer-generated hologram constructed as a transmission Fourier transform hologram and fitted in the frame. The computer-generated hologram 20 comprises minuscule cells having pitches &dgr;x and &dgr;y, with a reconstruction image area 30 defined by a range of spreading of ± first-order diffracted light of given wavelength from a diffraction grating having grating pitches 2&dgr;x and 2&dgr;y that are twice as large as the pitches of cells, and an input image pattern, reconstructed at that wavelength in a range of up to ⅔ of the reconstruction image area 30, is recorded in the computer-generated hologram.

Abstract: The invention relates to a holographic display for storing and reducing a spatial structure, having a holographic screen forming the master hologram, and having a projection device which illuminates the holographic screen in order to reproduce the spatial structure. The invention, for the holographic display to be constructed from a plurality of holographic screens which are respectively assigned to a dedicated projection device.

Abstract: A computer-generated hologram fabrication process that enables a plurality of original images to be observed with master-slave relations Original images 11, 12, a recording surface 20 and reference light R are defined on a computer, and a number of point light sources P11-1, . . . , P12-1, . . . as samples are defined on each original image. Given angles of spreading of object light beams emitted from individual point light sources are defined, and areas on the recording surface 20, at which object light beams emitted from point light sources defined on each original image 11, 12 with the thus limited given angles of spreading arrive, are determined as recording areas &agr;11 and &agr;12 corresponding to the original images 11 and 12. When there is an overlapping (hatched) portion in the recording areas, the overlapping portion is determined as a recording area corresponding to the master original image.

Abstract: The present invention is a phase-imaging technique by digital holography that eliminates the problem of 2&pgr;-ambiguity. The technique is based on a combination of two or more digital holograms generated using multiple wavelengths. For a two-wavelength experiment, the phase maps of two digital holograms of different wavelengths are subtracted which yields another phase map whose effective wavelength is inversely proportional to the difference of wavelengths. Using two holograms made with a 633 nm HeNe laser and a 532 nm doubled YAG laser an image was obtained that is a 3D reconstruction of a reflective surface with axial resolution of ˜10 nm over a range of −5 um, without any phase discontinuity over this range. The method can be extended to three wavelengths or more in order to reduce the effect of phase noise further.

Abstract: In an apparatus for detecting holographic data reproduced from a holographic medium, the holographic medium has an interference pattern and the holographic data is reproduced when a first portion of a reference beam is diffracted by the interference pattern within the holographic medium. A transmission beam detector detects a light intensity of a transmission beam which is a second portion of the reference beam, wherein the transmission beam is not diffracted to reproduce the holographic data and passes through the holographic medium. Then, a CCD (charge coupled device) controller generates a driving signal in accordance with the detected light intensity. Thereafter, a CCD detects the holographic data in response to the driving signal.

Abstract: The invention relates to a hologram carrier having a hologram surface and a reference surface to facilitate the acquisition of the hologram surface by a device. In this case, provision is made for the reference surface to comprise at least one step, which is arranged to interengage with a complementary formation on the device in order to align said device.

Abstract: A holographic display comprises a source of coherent light and an Electrically Addressable Spatial Light Modulator (EASLM) in the path of the light source. The EASLM is arranged in use to be driven successively by a set of sub-holograms which together correspond to a holographic image. Light guiding means is arranged to guide light output from the EASLM such that the sub-holograms are displayed successively in respective tiled regions of an EASLM projection surface.

Abstract: An optical display provided with a hologram element and a light source, wherein the hologram is a reflection hologram formed by a light beam which is obtained by utilizing light passing through a slit and has information on an object and a reference light beam which has an incident ligth path different from that of the light having the information on an object, and the reproduced image of the object is displayed using the light from the light source.

Abstract: Systems and methods are described for off-axis illumination direct-to-digital holography.

Abstract: An optical member 7 is bonded, at its rear side 7b, to a holographic stereogram 6. The front side 7a of the optical member 7 consists of parallel triangular prisms. Illumination light 9 is applied to the front surface 7a of the optical member 7 at a predetermined angle of, for example, 60°. The optical member 7 is made of, for example, optical glass or transparent plastic. Each triangular prism has an incidence surface 8, to which the illumination light is applied at right angles. The illumination light is applied to the interface 22 between the optical member 7 and the holographic stereogram 6, at an incidence angle &thgr; of, for example, 60°, thereby to suppress surface reflection of the illumination light 9 at the interface 22.

Abstract: A privacy filter for use on an electronic display screen, such as a PDA display screen or a laptop display screen, is constructed using holographic imaging technology. The privacy filter consists of a flexible, optically clear photopolymer film having a plurality of holographic images formed thereon. The key aspect of the present disclosure is constructing the master holographic images by imaging the master holographic recording plates at a severe side angle “off angle”. By shooting the hologram at this “off angle”, the resulting hologram is not visible to a person looking directly (perpendicularly) at the resulting hologram. However, the holograms are visible within the remaining fields of view to the right and to the left of center. Creation of the holograms in this manner creates an effective blocking tool for use in the context of a privacy filter.

Abstract: A method and system of projecting light on a planar surface to produce an image for tracing is disclosed. The system includes a projector that has a light source and a signal conditioner that is operably connected to the projector. A computer is operably connected to the signal conditioner. A scanner is connected to the projector. A test pattern from the computer is projected from the projector through the scanners to visually align an image to a sector on a work surface. A grid is operably aligned with the work surface. A geometric pattern from the computer is then projected by the projector on the planar work surface for tracing. The method comprises the steps of creating a pattern, tracing lines along the pattern on the planar work surface, cutting the pattern along the traced lines, discarding pieces of the planar surface outside the pattern, and placing edging along an outer edge of the pattern.

Abstract: The use of a holographic video screen which appears black, gray or colored in ambient light as the display surface in a vehicle, wherein a driver can view the screen while driving without taking his eyes of the road. Additionally, the display system containing such a video screen permits the projection and viewing of multiple images on a single screen.

Abstract: An observation optical system includes an image display element, a relay optical system having a plurality of lenses 4 and a first reflection-type volume hologram element (HOE), and an eyepiece optical system having a second reflection-type HOE. The observation optical system is arranged along the face to the side head of the observer. The first reflection-type HOE has a power and is configured to compensate for chromatic aberrations. The plurality of lenses is configured to compensate for decentered aberrations and chromatic aberrations. The second reflection-type HOE is a configured to exert power on bundles of rays and to compensate for chromatic aberrations. A light-transmitting plate is sandwiched between the first reflection-type HOE and the second refection-type HOE.

Abstract: Systems and methods are described for off-axis illumination direct-to-digital holography.

Abstract: In an image reconstructing apparatus 10 for reconstructing a hologram, when a lid 11 is nearly upright in relation to an apparatus body 12, a light emitted from an illumination light source 15 is projected at a predetermined angle of incidence to a hologram 17a placed on a mount surface 16a of a holder 16 of the apparatus body 12 while the light source 15 is being moved.

Abstract: A method is disclosed for reconstructing an image from a total internal reflection hologram that includes the steps of arranging the hologram in relation to the first face of a coupling body, generating a substantially collimated illumination beam, directing the beam through a second face of the coupling body so that it reconstructs the image recorded in the hologram, recycling at least once the light in the illumination beam that is reflected from the hologram by redirecting it through the second face of the coupling body so that it also reconstructs the image recorded in the hologram, and scanning the illumination and recycled beams across the hologram, for the purpose of increasing the effective reconstruction efficiency of the total internal reflection hologram.

Abstract: A method is provided for producing a holographic optical element that is comprised of at least one primary hologram (as defined herein) and at least one complementary hologram (as defined herein). The holographic optical element is useful as a security device, since it is relatively easily produced and yet is uncopyable in total. Also disclosed are methods for establishing the authenticity of the holographic optical element.

Abstract: The current invention comprises the recording of full parallax, one-step, full color holographic stereograms so as to properly display the resultant imagery when the hologram is mounted on a curved substrate after recording. It also comprises mounting the hologram on a substrate that can be curved in one or two dimensions, thereby producing any arbitrary shape. The hologram is scalable, making it possible to create curved holograms of unlimited size. The hologram can be generated for application to one of a variety of curved substrates, including hemi-cylindrical substrates with opaque backing to allow up to 180 degrees of horizontal view zone, and full cylinders with transparent backing to allow viewing through 360 degrees horizontally. It also includes adaptation to conical, spherical, and other curved geometric and irregular topographies.

Abstract: An illuminated colored display device provides a 360-degree viewable hologram, having the properties of a distortion free, monochromatic or full-color reconstruction from a single white light source, an extended vertical viewing aperture, and extended moving scene. These advantageous properties are provided by a rotating display device and a type of “synthetic” hologram composed of movie film frames or digital information. Each color component hologram consists of an array of noncontiguous small dots or thin stripes so that the three-color component holograms may be intermeshed without overlap of the dots or stripes. The component holograms themselves are vertically focused so that the composite hologram is white light viewable. The disclosed method includes the provision of a novel optical film holder and transport system.

Abstract: A display device has a plurality of light emitting elements for emitting lights, a display element for modulating the light emitting from the plurality of light emitting elements so as to convert it to an image light showing an optical image, a reflection type hologram element, having a positive optical power with respect to the lights from the plural light emitting elements, for diffracting and reflecting the lights from the plural light emitting elements to approximately one direction so as to guide the diffracted and reflected lights to the display element; and an enlarging optical system for forming an enlarged image of the optical image converted by the lights from the image display element. The plural light emitting elements are positioned in a plane approximately vertical to an optical path of the lights diffracted and reflected by the hologram element.

Abstract: An image recording apparatus and an image recording method can be suitably used for preparing a large number of edge-lit type holograms or holographic stereograms in a simple manner by copying. A hologram recording medium 11 is applied onto a principal surface 10a of a light-introducing block for copying 10 and held in contact with a master 15. Then, reference light L equivalent to reproducing light for reproducing the image of the master 15 is introduced into the light-introducing block for copying 10 through an end face thereof 10b.

Abstract: A system for producing a white-light interference hologram includes a camera adapted for recording a first and a second bitmap image of a scene from separate vantage points, and the separation distance of the vantage points, a computing engine adapted to compute three-dimensional x, y, and z characteristics of an interference hologram topology for the scene from the bitmap image and separation data, wherein x and y are two dimensional locations of bits in a bitmap of the topology and z is a depth dimension for each x,y bit, and a printer adapted to print in color the x,y bitmap, and to create the depth dimension z at each x,y bit location, providing thereby a three-dimensional interference hologram topology for the scene. In a preferred embodiment the depth dimension is created by electrophoresis, using a medium having an electrophoretic gel layer, with the ink applied to the gel in a bit-mapped pattern being ionic in nature, and capable of being migrated in the gel layer by electrophoresis.

Abstract: The invention provides a holographic optical device, including a light-transmissive substrate; a first holographic optical element carried by the substrate; at least one second holographic optical element carried by the substrate laterally of the first holographic optical element, and at least one third holographic optical element carried by the substrate laterally displaced from the first and second holographic optical elements; wherein the center of at least one of the first, second or third holographic optical elements is located outside a single, straight line.

Abstract: An observation optical system includes an image display element b 5, a relay optical system 6 having a plurality of lenses 4 and a first reflection-type volume hologram element (HOE) 8, and an eyepiece optical system having a second reflection-type HOE 9. The observation optical system is arranged along the face to the side head of the observer. The first reflection-type HOE 8 has a power and is configured to compensate for chromatic aberrations. The plurality of lenses is configured to compensate for decentered aberrations and chromatic aberrations. The second reflection-type HOE 9 is configured to exert power on bundles of rays and to compensate for chromatic aberrations. A light-transmitting plate 3 is sandwiched between the first reflection-type HOE 8 and the second reflection-type HOE 9. The light-transmitting plate 3 is configured so that light from the first reflection-type HOE 8 causes total reflection inside the light-transmitting plate 3 odd-numbered times equal to or greater than three times.

Abstract: Switchable holographic optical elements (HOEs) can used in systems and methods for projecting three-dimensional images, or for projecting two-dimensional tiled images with increased size and/or resolution. One of the methods may include sequentially displaying first, second, and third color components of a first two-dimensional image at an object plane. The first two dimensional image represents a first slice of a three-dimensional image. As the first, second, and third color components are displayed, first, second and third HOEs may be activated so that the activated first switchable HOE focuses the first color component of the first two-dimensional image onto a first image plane, the activated second switchable HOE focuses the second color component of the first two-dimensional image onto the first image plane, and the wherein the activated third switchable HOE focuses the third color component of the first two-dimensional image onto the first image plane.

Abstract: A resonator system is disclosed for use in illuminating a diffractive element. The system includes a source of an electromagnetic field having a wavelength of &lgr;, and first and second optical elements, each of which is at least partially reflecting.

Abstract: This invention relates to a solar control film that blocks the sunlight, when applied to various windows of automobiles, buildings or exhibition places and that prevent any second accident caused by broken glasses at an accident. From the solar control film, a surface protective layer, a plastic film substrate, a hologram-engraved layer, a metal deposition layer, a pressure sensitive adhesive layer and a release film are laminated in due order. The solar control film of this. Hence the above-described solar film has a basic function such as an excellent blocking rate of visible and infrared rays, while demonstrating an additional antifog action and an elegant look due to the hologram effect.

Abstract: A hologram screen 1 for displaying an image by diffracting and scattering image light 31 projected from an image projection apparatus 2. An upward/downward light scattering device 13 for scattering light incident from at least one upward/downward specific angle range spreading obliquely upward or obliquely downward is placed on the image projection apparatus side of a hologram device 12 in the hologram screen 1, and a leftward/rightward light scattering device 14 for scattering light incident from a leftward/rightward specific angle range spreading obliquely leftward and obliquely rightward is placed between the hologram device 12 and the upward/downward light scattering device 13 or on the image projection apparatus side of the upward/downward light scattering device 13.

Abstract: A projection screen (30) for representation of images by back-projection comprises a plurality of holographic-optical elements (10) arranged in one plane. The holographic-optical elements are illuminated by a projector (14) comprising three projection devices (22,24,26). Each projection device (22,24,26) generates a light bundle (16,18,20) respectively including the chromatic components of an image to be projected. Each holographic-optical element (10) comprises at least one lens and one diffraction grating which are diffracted in such a manner by the different light bundles (16,18,20) that the holographic-optical element (10) will emit an exiting light bundle (28) with an identical exit angle (&bgr;) in the direction of the viewer (12). Such a projection screen will scatter the light only to a small extent so that the projection screen can be used also at daylight and for large-surface image projection.

Abstract: An observation device for observing a reproduced image which is reproduced by an image reconstructor uses a special light different from normal light. A special image reproducing and observing device 2 enables observation of reproduced image by irradiating an image reconstructor 4 with a special light to reproduce an image. The special image reproducing and observing device 2 has: light sources 6 and 8 which produce special light; a power supply 10 which causes a light emission by the light sources 6 and 8; and a irradiation device 8 and 12 which enables irradiation of an image reconstructor 4 with a special light that is produced at the light source 6 and 8.

Abstract: A method is disclosed for reconstructing an image from a total internal reflection hologram that includes the steps of arranging the hologram in relation to the first face of a coupling body, generating a substantially collimated illumination beam, directing the beam through a second face of the coupling body so that it reconstructs the image recorded in the hologram, recycling at least once the light in the illumination beam that is reflected from the hologram by redirecting it through the second face of the coupling body so that it also reconstructs the image recorded in the hologram, and scanning the illumination and recycled beams across the hologram, for the purpose of increasing the effective reconstruction efficiency of the total internal reflection hologram.

Abstract: A method is provided for producing a holographic optical element that is comprised of at least one primary hologram (as defined herein) and at least one complementary hologram (as defined herein). The holographic optical element is useful as a security device, since it is relatively easily produced and yet is uncopyable in total. Also disclosed are methods for establishing the authenticity of the holographic optical element.