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

Abstract: The invention relates to a method for presenting interventional instruments in a 3D data set of an anatomy to be treated. A 3D data set of the anatomy is recorded before introduction of an interventional instrument. Once the interventional instrument has been applied, the spatial position of the instrument is determined by x-ray fluoroscopy from images created at two different angulations. A 3D model of the instrument is formed from the x-ray images. The 3D model of the instrument is fused with the 3D data set of the anatomy. A 3D hologram is reproduced from the fused 3D data set. The 3D hologram is repeatedly reproduced in real time to follow the application of the instrument in the presentation.

Abstract: The present invention relates to a method for fabricating a computer-generated hologram or a holographic stereogram which can reconstruct a three-dimensional object having visualized cross-sectional surfaces, wherein the three-dimensional object composed only of surface data is processed to have the visualized cross-sectional surfaces on a given cross section thereof by adding surface data to the cross-sectional surfaces.

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: A system includes a computer generated hologram (CGH) design plane and a processor capable of representing a three dimensional object. The processor is configured to represent a surface of the three dimensional object by a facet, impose a grid defining a set of nodes upon the facet, and associate object points with each node of the grid. The processor is further configured to orient the facet to include a common global origin in the CGH design plane and displace the object points away from their associated node in a random or pseudo random direction parallel to the CGH design plane.

Abstract: A new way of mixing instrumental and digital means is described for the general field of wave front sensing. The present invention describes the use, the definition and the utility of digital operators, called digital wave front operators (DWFO) or digital lenses (DL), specifically designed for the digital processing of wave fronts defined in amplitude and phase. DWFO are of particular interest for correcting undesired wave front deformations induced by instrumental defects or experimental errors. DWFO may be defined using a mathematical model, e.g. a polynomial function, which involves coefficients. The present invention describes automated and semi-automated procedures for calibrating or adjusting the values of these coefficients. These procedures are based on the fitting of mathematical models on reference data extracted from specific regions of a wave front called reference areas, which are characterized by the fact that specimen contributions are a priori known in reference areas.

Abstract: A laser machining device is provided with a laser light source, a spatial light modulator, a driving unit, a control unit, and a condensing optical system. The control unit selects a basic hologram corresponding to each basic machining pattern included in a whole machining pattern in a workpiece from a plurality of basic holograms stored by the storage unit, and determines a display region of the basic hologram in the spatial light modulator so that the deviation of the value of “I?/n” becomes small for the selected respective basic hologram when the intensity of a laser beam input to a display region of the basic hologram in the spatial light modulator is defined as I, the diffraction efficiency of the laser beam in the basic hologram is defined as ?, and the number of condensing points in a basic machining pattern corresponding to the basic hologram is defined as n.

Abstract: A recording apparatus includes a drive unit that rotationally drives a holographic recording medium including a recording layer and a track forming layer that includes guide tracks formed at constant intervals in a radial direction, where a signal beam and a reference beam are emitted to the recording layer so that a hologram is recorded in accordance with the signal beam, a signal beam generating unit, a reference beam generating unit, a recording unit that emits the signal beam and reference beam into the medium and records the hologram, a rotation control unit that controls the drive unit so that the medium is rotationally driven at a constant rotation speed, and a recording control unit that selects some of the guide tracks so that radial-direction recording intervals of the holograms are statistically decreased towards the outer periphery and controls the recording unit to record the holograms along the selected tracks.

Abstract: The data defining an object to be holographically reconstructed is first arranged into a number of virtual section layers, each layer defining a two-dimensional object data sets, such that a video hologram data set can be calculated from some or all of these two-dimensional object data sets. The first step is to transform each two-dimensional object data set to a two-dimensional wave field distribution. This wave field distribution is calculated for a virtual observer window in a reference layer at a finite distance from the video hologram layer. Next, the calculated two-dimensional wave field distributions for the virtual observer window, for all two-dimensional object data sets of section layers, are added to define an aggregated observer window data set. Then, the aggregated observer window data set is transformed from the reference layer to the video hologram layer, to generate the video hologram data set for the computer-generated video hologram.

Abstract: The invention relates to an optical reflection system with a reflection element for reflecting reconstruction light waves, an entry-side focal point, from which the reconstruction light waves come when they hit the reflection element, and an exit-side focal point, to which the reconstruction light waves propagate after being reflected from the reflection element. The invention further relates to a tracking system and a holographic projection system with such optical reflection system, and a corresponding holographic projection method.

Abstract: The inventive method for recording data on an optical lens (2) consists in recording a data-containing source image, in generating the hologram (3) of the image source and in recording said hologram on the lens surface portion ranging from 0.5 mm2 to 15 mm2. The data can be read-out by illuminating said lens by means of a light beam (101) in the hologram area. A read-out image (105, 106) which reproduces the source image and on which data is readable is formed at a distance from the lens. Said lens can be embodied, in particular in the form of an ophthalmic lens.

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: A three-dimensional hologram image display apparatus displays a three-dimensional hologram image by use of computed interference fringe patterns. The three-dimensional hologram image display apparatus includes a light modulation device which has an electro-optical effect in which a refractive index is varied in accordance with an applied electric field intensity; and an electric field controller configured to record computed interference fringe patterns in the light modulation device by varying an electric field intensity applied to the light modulation device in accordance with the computed interference fringe patterns.

Abstract: A method for reducing speckle patterns of a three-dimensional holographic reconstruction is disclosed. A controllable light modulator into which a hologram of a three-dimensional scene is coded is illuminated by coherent light, a reconstruction lens transforms the modulated light into an eye position and reconstructs the three-dimensional scene in a reconstruction space and a control means controls the illumination. This provides a holographic reproduction device in which the speckle patterns occurring during reconstruction of a three-dimensional scene are reduced. According to one embodiment, a next-to-real time method is presented using a carrier medium of conventional image refresh rate.

Abstract: The data defining an object to be holographically reconstructed is first arranged into a number of virtual section layers, each layer defining a two-dimensional object data sets, such that a video hologram data set can be calculated from some or all of these two-dimensional object data sets. The first step is to transform each two-dimensional object data set to a two-dimensional wave field distribution. This wave field distribution is calculated for a virtual observer window in a reference layer at a finite distance from the video hologram layer. Next, the calculated two-dimensional wave field distributions for the virtual observer window, for all two-dimensional object data sets of section layers, are added to define an aggregated observer window data set. Then, the aggregated observer window data set is transformed from the reference layer to the video hologram layer, to generate the video hologram data set for the computer-generated video hologram.

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: The present invention relates to a hologram viewing arrangement, to an alignment device, to a display device, to a device for aligning first and second members and to a device for aligning an optical beam with a desired target. A hologram viewing arrangement comprising a pixellated phase mask substrate (20) and a pixellated hologram display substrate (40), wherein the hologram display substrate is arranged to store data representing at least two distinct images (3a-3d), the arrangement being such that disposing the phase mask in a first position with respect to the display substrate enables one of the at least two images to be visible and disposing the phase mask in a second position with respect to the display substrate enables another of the at least two images to be visible.

Abstract: A holographic display includes 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: An object of the present invention is to provide an electron microscope that employs a hologram of a diffraction pattern to reconstruct a microscopic image involving no imaging aberration due to image forming lenses, as well as a combined illumination lens used for such an electron microscope.

Abstract: For the purpose of preparing a computer-generated hologram, which has very high resolution and many numbers of parallaxes, the present invention provides a computer-generated holographic stereogram, wherein a virtual point light source group (11) is set up spatially on a side opposite to the observation side of the hologram (12), luminance angular distribution AWLci (?xz, ?yz) of divergent light diverged from each of the virtual point light sources of said virtual point light source group toward observation side is divided by angular division, and within the divided angle, among the multiple images positioned on the plane of said virtual point light source group (11), a divergent light to be equal to the divergent light diverged from a point of amplitude equal to the density of pixel of the image corresponding to each of divided angle or equal to a value in a certain fixed relation with the density of the images at the position of the virtual point light source is recorded as the object light (1) at one of th

Abstract: The invention relates to a display system for diagnostic image systems for reproducing three-dimensional medical images. The display system has at least one holographic projection facility that is connected to the diagnostic image system. The projection device reproduces a hologram of the three-dimensional medical images in an examination or intervention room.

Abstract: A conoscopic holographic system and a method for imaging a scene characterized by a surface having a three-dimensional shape. The system utilizes an optical source, which illuminates the scene with substantially linear distributions of light, and independent register of a plurality of elementary conoscopic holograms in the image plane. Each elementary conoscopic hologram represents the imaging of a single emitting point of the illuminated scene. The optical source is translated relative to the scene to generate a sequence of optical holograms, and a weighted reconstruction of the holograms is performed, in a computer process, at a median plane to devise the three-dimensional shape of the imaged scene.

Abstract: A device for holographic reconstruction of three-dimensional scenes includes optical focusing means which directs sufficiently coherent light from light means to the eyes of at least one observer via a spatial light modulator that is encoded with holographic information. The device has a plurality of illumination units for illuminating the surface of the spatial light modulator; each unit comprises a focusing element, and a light means that emits sufficiently coherent light such that each of these illumination units illuminates one separate illuminated region of the surface, whereby the focusing element and the light means are arranged such that the light emitted by the light means coincides close to or at the observer eyes.

Abstract: The present invention relates to a three-dimensional image displaying apparatus, or the like, that has a simple structure capable of displaying a high-quality reconstruction image by effectively making use of the focusing function of the observer's eyes. The three-dimensional image displaying apparatus comprises a spatial light modulation element, an illumination optical system, and a lens as a reconstruction image converting optical system. At least one of the bright point interval and initial phase values of the respective bright points constituting a target reconstruction image to be displayed is set such that peaks of the reconstruction light reaching a region, where the observation of reconstruction image obtained through diffraction of a specified order in the spatial light modulation element is permitted, are produced at different plural points on the back focal plane of the lens.

Abstract: The present invention relates to a method for the production of polarization holograms, an apparatus for the production of polarization holograms and the use of the polarization holograms according to the invention as data stores, security features or diffractive optical elements for performing conventional optical functions.

Abstract: The invention provides a process capable of fabricating a cholesteric liquid crystal medium having a volume hologram with efficiency yet without recourse to complicated steps such as an alignment step. This is achievable as follows. A volume hologram layer is formed on a substrate, and a cholesteric liquid crystal layer is then formed on another substrate comprising a center substrate film that is subjected to bondable treatment. The volume hologram layer is applied to the center substrate film that is subjected to bondable treatment, and placed in a state where the volume hologram layer and cholesteric liquid crystal layer are laminated together via the substrate. The substrate is peeled off the volume hologram layer, and an adhesive layer is formed on the surface of the volume hologram layer off which the substrate is peeled off, followed by the provision of the substrate on the adhesive layer.

Abstract: We describe a method of projecting a colour image on a screen holographically. The method includes: inputting colour image data including data for at least two colour planes of said image, a first, longer wavelength colour plane and a second, shorter wavelength colour plane; generating data for respective first and second holograms from said first and second colour planes, said first hologram having a greater resolution than said second hologram; and displaying said first and second holograms in turn on a common spatial light modulator (SLM) illuminated by light of respective said first and second wavelengths to project said colour image onto said screen; and wherein a scaling in resolution between said first and second holograms is dependent on scaling between said first and second wavelengths such that, when projected on said screen pixels of said image generated by said first and second holograms have substantially the same pitch.

Abstract: An adaptive optics system comprises a beamsplitter configured to divide an incoming beam with an aberrated wave front into a first input beam and a second input beam, a microelectromechanical system configured to reflect the first input beam onto an image plane, and a self-reference wave front generator configured to spatially filter the second input beam to form a reference beam, and to interfere the reference beam with the first input beam on the image plane to form a hologram. The system further comprises an imaging device configured to capture an image of the hologram on the image plane, and one or more processors.

Abstract: A method for fabricating a computer-generated hologram or a holographic stereogram can reconstruct a three-dimensional object having visualized cross-sectional surfaces, wherein the three-dimensional object composed only of surface data is processed to have visualized cross-sectional surfaces on a given cross section thereof by adding surface data to cross-sectional surfaces.

Abstract: This invention relates to optical systems for holographic projectors. We describe a holographic image projection system, the system including: a spatial light modulator (SLM) for displaying a hologram; first optics to provide an input beam to said SLM; second optics to process an output beam from said SLM to provide a displayed image; and a hologram processor to receive image data for display and to output data to said SLM to display a hologram to provide said displayed image; and wherein at least one lens of said first optics or said second optics is encoded in said hologram.

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: The invention provides a fabrication process for a computer-generated hologram 1 wherein amplitude information and phase information are recorded on a given recording surface by means of computation by a computer. The computer-generated hologram 1 is characterized by having a first direction X and a second direction Y orthogonal to the first direction X, and parallax in the first direction X alone. The hologram 1 comprises unit areas B1, B2, B3, . . . , Bm, . . . BM, each one having a given width in the second direction Y. In each unit area B1, B2, B3, . . . , Bm, . . . BM, there is a diffraction pattern having a spatial frequency Cm1, Cm2, Cm3, . . . , Cmt, . . . CmT that varies in the second direction.

Abstract: To prepare very high resolution computer-generated hologram having many numbers of parallaxes, a computer-generated holographic stereogram, with virtual point light source group set up spatially on a side opposite to the hologram observation side, luminance angular distribution AWLci (?xz, ?yz) of divergent light from each virtual point light sources of said group toward observation side is divided by angular division, and within the divided angle, among the multiple images positioned on the plane of said group, divergent light equal to the divergent light diverged from a point of amplitude equal to the density of pixel of each divided angle corresponding image or equal to a value in a certain fixed relation with the density of the images at the position of the virtual point light source is recorded as the object light at one of the positions on the observation side of the virtual point light source group.

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: 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: Provided is an image display apparatus that has resistance to dust and water, that is compact and lightweight, and that has see-through characteristics. The image display apparatus is provided with a display device displaying an image, a prism guiding light of the image displayed by the display device to an optical pupil, and transmitting outside light such that an outside world can be viewed therethrough, and an enclosure housing and holding the display device and part of the prism. Here, a first sealing member is provided so as to make contact with a part around the prism where image light is not reflected and with the enclosure.

Abstract: A multi-color off-axis digital holographic system and the imaging method thereof are disclosed. The multi-color off-axis digital holographic system comprises: a plurality of light emitting diodes, for provide a red (R) beam, a green (G) beam and a blue (B) beam; an interference object lens module, for receiving the R, G, and B beams to generate a beam containing an interference signal; a color imaging device, for receiving the beam containing the interference signal and thus forming a hologram on a surface of the color imaging device by holographic interference while registering the hologram; and a processing device, for receiving the registered hologram form the color imaging device; wherein the processing device perform a zero-filling and reconstructing operations upon the received hologram to obtain phase information of the R, G and B beams.

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: A device for holographic reconstruction of three-dimensional scenes includes optical focusing means which directs sufficiently coherent light from light means to the eyes of at least one observer via a spatial light modulator that is encoded with holographic information. The device has a plurality of illumination units for illuminating the surface of the spatial light modulator (SLM); each unit comprises a focusing element (21/22/23 or 24), and a light means (LS1/LS2/LS3 or LS4) that emits sufficiently coherent light such that each of these illumination units illuminates one separate illuminated region (R1/R2/R3 or R4) of the surface, whereby the focusing element and the light means are arranged such that the light emitted by the light means (LS1-LS4) coincides close to or at the observer eyes.

Abstract: According to the present invention, video image data is converted into spatial frequency information using Fourier transformation. The spatial frequency information is provided to 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, 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 projecting unit.

Abstract: Holographic optical traps using the forces exerted by computer-generated holograms to trap, move and otherwise transform mesoscopically textured materials. The efficacy of the present invention is based upon the quality and nature of the diffractive optical element used to create the traps and dynamically use them. Further a landscape of potential energy sites can be created and used to manipulate, sort and process objects.

Abstract: This invention relates to a holographic projection device with an array of mirror elements in the form of micro-mirrors. The holographic projection device comprises at least one light modulator device, which contains the array of mirror elements, for an enlargement of a reconstruction space for a reconstructed scene. Each mirror element is coupled with at least one actuator. The actuators tilt the corresponding mirror elements and/or displace them axially in at least one direction. Thereby, a wave front for the representation of a reconstructed scene is directly modulated. The holographic projection device comprises an optical system for the projection of the modulated wave front into at least one observer window in an observer plane.

Abstract: A hologram reproduction method for reproducing a hologram from an optical recording medium in which the hologram is recorded by Fourier transforming a signal light, in which digital data is represented by an image of intensity distribution, and a reference light, and simultaneously irradiating the lights in a state in which a direct current component is removed from at least the Fourier transformed signal light onto the optical recording medium is provided. The method including: irradiating a read out reference light onto the optical recording medium, and generating a diffracted light from the recorded hologram; generating all or a part of a direct current component contained in a Fourier transformed image of the signal light; combining the diffracted light and the generated all or a part of the direct current component, and generating a combined beam; and reproducing the signal light by inverse-Fourier transforming the combined beam.

Abstract: The invention concerns a holographic method with numerical reconstruction for obtaining an image of a three-dimensional object, said method employing a digitalised hologram of an object, and comprising a step A. wherein, starting from the digitalised hologram, extracting a phase image of said object corresponding to a bidimensional matrix MD of distance values; a step B. wherein a mono-dimensional subassembly SD of the distance value assembly present in matrix MD of the method step A is selected, subassembly SD containing distance values dk; a step C. wherein for each distance value dk, extracting from matrix MD a iso-level assembly IQdk corresponding to a mono-dimensional assembly of bidimensional coordinates of said object, a step D. wherein for each distance value dk, reconstructing, starting from the digitalised hologram, a bidimensional matrix IMdk of intensity values relevant to said object; a step E.

Abstract: The present invention provides a computer generated hologram which forms a light intensity distribution on a predetermined plane by giving a phase distribution to a wavefront of incident light, comprising an anisotropic layer whose refractive index with respect to linearly polarized light in a first direction is different from a refractive index of the anisotropic layer with respect to linearly polarized light in a second direction perpendicular to the linearly polarized light in the first direction, and an isotropic layer whose refractive index with respect to the linearly polarized light in the first direction is equal to a refractive index of the isotropic layer with respect to the linearly polarized light in the second direction.

Abstract: An optical phase processing system for a scattering medium. A first beam has a direction and a wavefront and the first beam is configured to enter a holographic recording medium. A scattering medium is illuminated by a signal beam generating at least one scattered beam. An interference pattern is recorded from the at least one scattered beam and the first beam. A second beam is generated in a direction opposite to the direction of the first beam, the second beam having a wavefront and a phase substantially opposite to a phase of the wavefront of the first beam, and the second beam is configured to enter the holographic recording medium. The second beam and the interference pattern interact to generate at least one reconstructed beam having a phase substantially opposite to a phase of the at least one scattered beam, and the at least one reconstructed beam is configured to be viewable through the scattering medium.

Abstract: This invention relates to electronic devices incorporating a holographic projector.

Abstract: The invention concerns a quantitative phase-contrast digital holography method for the numerical reconstruction of images, comprising the following steps: A. acquiring a digital hologram of an investigated object; B. reconstructing the digital hologram in a reconstruction plane; C. reconstructing the complex field for the digital hologram; D. obtaining the phase map starting from the complex field; the method being characterised in that it further comprises the following steps: E. applying to the digital matrix of any step A, B, C a shear sx and/or sy respectively along directions x and/or y; F. subtracting the matrix obtained in step E from the starting matrix of step E, or vice versa; G. integrating the obtained matrix along directions x and/or y; H. calculating at least a defocus aberration term; I. subtracting said at least a term calculated in step H from the matrix obtained in step G, the steps G to I being subsequent to step D.

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: Producing a digital hologram-in a storage medium includes: (i) focusing a write beam onto the storage medium; (ii) moving the write beam two-dimensionally relative to the storage medium; (iii) focusing a scanning beam onto a beam-guiding mask having a plurality of tracks; (iv) moving the scanning beam two-dimensionally relative to the mask, the movement of the scanning beam being coupled with the movement of the write beam; (v) generating a position control signal when the position of the scanning beam deviates from the scanned track by a predefined value; (vi) controlling the position of the write beam on the storage medium with the aid of the position control signal; and (vii) writing the hologram by introducing radiation energy point by point, the intensity of the write beam being controlled as a function of the position of the write beam on the storage medium.