Abstract: A holographic recording medium includes a holographic recording carrier including a first light transmittable substrate, a second light transmittable substrate and a holographic recording layer sandwiched therebetween, a first antireflection film formed on the surface of the first light transmittable substrate and a second antireflection film formed on the surface of the second light transmittable substrate, and optical characteristics of the first antireflection film and those of the second antireflection film are determined to be different from each other the thus constituted holographic recording medium can achieves improved data recording characteristics and data reproducing characteristics using an object beam and a reference beam, and concurrently enables desired positioning of an object beam and a reference beam, or only the reference beam, and detection of the address of the region in which data are being recorded or from which data are being reproduced using a position control beam.

Abstract: A method for forming fine concavo-convex patterns by using a relief formation material 3 having a relief formation layer 2 composed of a resin having thermoplasticity and a relief pattern sheet 6 having on a surface thereof fine concavo-convex patterns 5, wherein a photothermal conversion layer 7 is formed in the relief formation material 3 or the relief pattern sheet 6; the photothermal conversion layer 7 is irradiated with light 8 to make the photothermal conversion layer 7 generate heat in the state that the relief formation layer 2 is brought into contact with the fine concavo-convex patterns 5; and the fine concavo-convex patterns 5 are formed on the relief formation layer 2.

Abstract: Method for producing an exposed substrate, which has at least two different image areas. The substrate is provided with at least two photoresist layers, which are adjusted to the type of image areas to be produced.

Abstract: A holographic recording medium has at least a recording layer with a thickness of L which comprises a recording layer material having an absorption coefficient of ? and containing a photorefractive material, wherein the optical density ?L represented by the product of the absorption coefficient ? and the thickness L is in the range from 0.3 to 2.0.

Abstract: A novel liquid photoreactive asymmetric acrylate compound containing sulfur, aromatic moieties, and optionally bromine, and having high dynamic range sensitivity is disclosed. The acrylate compound is a monomer for a photoimageable system. In one embodiment, when about 2–8% by weight of the acrylate compound is dissolved in a two-component urethane matrix system and incorporated in an optical article formed by reacting the two-component urethane matrix system, the optical article shows a sensitivity of about 4 or more and a shrinkage during the formation of the optical article of about 0.05% versus a sensitivity of 2.26 and a shrinkage of 0.13% when tribromophenyl acrylate, a commercial monomer, was used.

Abstract: Information recorded as a hologram in a predetermined position of an optical recording medium is reproduced, and subsequently the reproduced information is re-recorded and retained in the same position as the predetermined position as a hologram. Alternatively, information recorded as a hologram in a predetermined position of an optical recording medium is reproduced, and subsequently the reproduced information is re-recorded and retained in a position different from the predetermined position as a hologram easily.

Abstract: A simplified method is provided for recording identification information, such as a serial number or the like, in a hologram-recorded film simultaneously with hologram duplication. The method includes the steps of coupling a hologram recording film with a master hologram plate having a master hologram, the master hologram plate having a reflective area adjacent the master hologram; and directing laser beams towards the master hologram plate to induce interference between incident laser light and diffraction laser light from the master hologram in the recording film, at least some of the laser beams radiating the reflective area through a transmission type controllable display device to record a pattern in the hologram recording film corresponding to a pattern displayed at the transmission type controllable display device.

Abstract: Narrow-line holographic filters that can include a plurality of lines and that can be structured to provide a large aperture device. Materials that can be used to construct filters include glasses, photorefractive crystals such as lithium niobate and photorefractive thick polymers. The filters are fabricated by assembling a plurality of elements having the same one or more narrow line holographic filter patterns written thereon, in mutual orientation such that each element has a surface defined by a length and a width adjacent a corresponding surface of a neighboring element, and has a surface defined by a thickness and one of a length and a width accessible to impinging illumination. Filters exhibiting a plurality of characteristic narrow lines, and having arbitrarily large apertures can be fabricated. Methods of fabricating and using the filters are described.

Abstract: Polymeric material suitable for the preparation of optical recording media for volume data storage is disclosed. The molecular structure of the material contains a main chain derived from any of poly(meth)acrylate, poly(meth)acrylamide, polysiloxane, polyurea, polyurethane, polyester, polystyrene and cellulose, and the side chains contain a) azobenzene dye, b) form anisotropic grouping, and c) at least one monomer selected from the group consisting of where R=H or methyl, R? and R? independently denote CnH2n+1 or CnH2n-OH and R?? denotes —CnH2N—OH.

Abstract: System and method for providing gain and thresholding to a holographic data parallel recording and replication system incorporating independent angular address assignment. A plurality of information bearing light beams in an information bearing light beam arm of a data recording system and a plurality of reference light beams in a reference light beam arm of the data recording system are mutually interfered to store a plurality of spatially separate, spatially modulated light intensity patterns in a holographic data storage medium in a data recording operation. During the data recording operation, the plurality of information bearing light beams are repeatedly circulated through the holographic data storage medium using a resonant cavity formed along the information bearing light beam arm of the holographic recording system.

Abstract: The present invention relates to the laser inscription of a flexible inner support layer of a multilayered support unit, which is distinguished by the fact that the laser inscription of the inner support layer is carried out through one or more flexible outer laser-inactive support layers which are separate or can be separated from one another.

Abstract: A method of increasing the efficiency of a multiphoton absorption process and apparatus. The method includes: providing a photoreactive composition; providing a source of sufficient light for simultaneous absorption of at least two photons; exposing the photoreactive composition to at least one transit of light from the light source; and directing at least a portion of the first transit of the light back into the photoreactive composition using at least one optical element, wherein a plurality of photons not absorbed in at least one transit are used to expose the photoreactive composition in a subsequent transit.

Abstract: A photosensitive material, suitable for image-wise recording, e.g., holographic recording of data or other information, comprises an organic species in an organic-inorganic matrix, the organic species comprising a material having a refractive index which changes upon exposure to actinic radiation. The organic-inorganic matrix may be an organically modified glass. The photo-sensitive material may be made using the sol-gel process.

Abstract: A system and method capable of providing high data rate data copying and recording in holographic data storage while maintaining the copied data's signal-to-noise ratio. This is achieved by using optically-based parallel signal processing. In one preferred embodiment, the present invention uses a plurality of optical resonating cavities to provide thresholding and gain functions via positive feedback.

Abstract: Provided in a photomask for use in production of a hologram element having desired optical characteristics, a method for producing a hologram element, and a hologram element having desired optical characteristics. The first photomask is used for photolithography-based production of a hologram element having a hologram divided into two regions carrying a diffraction grating. The first photomask includes the first, second mask region having the non-light-transmitting mask portion and the light-transmitting portion, for forming the diffraction gratings of the regions of the hologram. The two mask regions differ in alignment-direction-wise arrangement interval for the light-transmitting portions and in ratio of the alignment-direction-wise width to the alignment-direction-wise arrangement interval for the light-transmitting portions.

Abstract: A method is disclosed for forming an array of focusing elements for use in a lithography system. In accordance with an embodiment, the method includes the steps of providing a master element that includes at least one diffractive pattern at a first location with respect to a target surface, illuminating the master element to produce a first diffractive pattern on the target surface at the first location, moving the master element with respect to the target surface to a second location with respect to the target surface, and illuminating the master element to produce a second diffractive pattern on the target surface at the second location.

Abstract: A holographic data storage medium has a polymer film which is set up as a storage layer whose refractive index can be changed locally by heating. The polymer film is set up for the storage of optical phase information via the local optical path length of the polymer film, which is illuminated in transmission when the information is read out. To the polymer film, there can be assigned an absorber dye, in order to at least partly absorb a write beam to input information and to give up the heat produced in the process at least partly locally to the polymer film. Preferably, a reflective layer is arranged behind the polymer film.

Abstract: A hologram fabricating apparatus includes a coherent light generator, two micro-display devices and a telecentric system. The coherent light generator provides a first coherent light and a second coherent light. Each micro-display device has a plurality of pixel elements laid thereon. The first coherent light and the second coherent light project respectively to the two micro-display devices. The telecentric system is located between the micro-display devices and a photoresist sheet to converge the projecting light on the photoresist sheet to generate interference stripes. Each pixel element may be adjusted independently to determine whether the first coherent light and the second coherent light projected to the pixel element to be projected to the telecentric system.

Abstract: In an example holographic data storage medium, which has a polymer film which serves as a storage layer and can be changed locally by heating, the polymer film is set up as a top layer of the data storage medium. Arranged underneath the polymer film is an absorber layer which has an absorber dye. The absorber dye is set up to at least partly absorb a write beam serving to put information in and to discharge the heat produced in the process at least partly locally to the polymer film. In an advantageous refinement of the example data storage medium, there is an adhesive layer underneath the absorber layer and a partly transparent reflective layer between the polymer film and the absorber layer.

Abstract: Disclosed is a hologram transfer film which can realize easy and good transfer of a hologram and, at the same time, can realize stable transfer of the hologram in a transfer process. The hologram transfer film comprises: a substrate film; and a transfer layer provided on the substrate film, the transfer layer comprising a hologram-forming layer and a heat-sensitive adhesive layer provided in that order on the substrate film, the hologram-forming layer having a breaking strain of 0.5 to 15% at 25° C. and a breaking strain of 0.5 to 30% at 120° C.

Abstract: A volume-phase holographic diffraction grating device is provided that can be optimized for use with very short wavelength light, such as light in the ultraviolet (UV) spectral region. The device comprises a cover and a substrate, both formed of a glass material. A layer of gelatin material is disposed between the cover and the substrate member, and has holographically-formed varying indexes of refraction formed therein to set up the interference pattern. The gelatin material has a thickness between 0.5 and 1 micron that makes it suitable for diffracting light in the UV spectral region, long-lived, and very efficient.

Abstract: A holographic recording medium according to the present invention includes a holographic material layer in which information is to be recorded by irradiating the same region with information light corresponding to the information to be recorded and reference light to read the recorded information. The holographic material layer is divided into a plurality of recording zones by a plurality of light shielding walls. The light shielding wall is formed of a material which does not transmit bleaching light to be applied to the recording zone in which a recording process has been performed and the recorded information is to be fixed.

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

Abstract: New photosensitive acrylic material compositions for fabrication of holographic recording materials (HRMs) are provided. These compositions are comprised of polymerizable acrylic monomers and light absorbing dyes, and when polymerized they are thermally stable, light sensitive, hard and inert to common chemicals. Methods of fabricating HRMs with symmetric concentration distribution of the dye are also provided.

Abstract: A recording medium (1) for hologram comprises a hologram recording layer (3) comprised of photo-polymer layer is formed on a base (2) comprised of colorless and transparent resin film, etc. and a protective layer (4) comprised of colorless and transparent resin film, etc. formed on the hologram recording layer (3). As such base (2) and protective layer (4), material having less double refraction is used. Optical axis of double refraction when such components are configured to be strip-shaped is allowed to be a direction of the longer side or a direction of the shorter side.

Abstract: An optical storage system and method having separate, independent format hologram writing and data writing mechanisms to allow optimization of data writing separately from format hologram recording. In its most general terms, the invention comprises an optical medium having a first, photoactive material responsive to a first, format hologram recording condition and a second photo-active material, responsive to a second, data writing condition, which is dispersed or dissolved in the first photoactive material. The second photoactive material may additionally be “erasable” under a third, erasing condition. The second photoactive material is preferably in the form of microparticles, microdroplets or microcapsules which are dispersed throughout the first photoactive material.

Abstract: Fiber optic devices including volume Bragg grating (VBG) elements are disclosed. A fiber optic device may include one or more optical inputs, one or more VBG elements, and one or more optical receivers. Methods for manufacturing VBG elements and for controlling filter response are also disclosed. A VBG chip, and fiber optic devices using such a chip, are also provided. A VBG chip includes a monolithic glass structure onto which a plurality of VBGs have been recorded.

Abstract: The invention relates to a lithograph for producing digital holograms in a storage medium (4), having a light source (6, 10) for producing a write beam (12) with a predefined beam cross section, having a writing lens (14) for focusing the write beam (12) onto the storage medium (4) to be written, the writing lens (14) being arranged in a lens holder (16), and having drive means for the two-dimensional movement of the write beam relative to the storage medium. The technical problem of writing computer-generated holograms as quickly as possible and with little effort by means of optical lithography is solved in that a first drive device (18) is provided for moving the lens holder (16) substantially at right angles to the write beam (12) and in that the aperture of the writing lens (14) is smaller than the beam cross section of the write beam (12). The inventon also relates to a method for the lithographic production of a hologram in a storage medium.

Abstract: The present invention provides a method and apparatus for a multilayer optical articles. A method comprises forming a first multilayer article with a first substrate and a second substrate with a first adherent disposed between the first and second substrate. A first surface of a third substrate is then grasped with a first holder and a second adherent is then disposed on one or more surfaces selected from a second surface of the third substrate and a surface of the first multilayer article while the multilayer article is grasped by a second holder. The second adherent is then at least partially cured while the first and second holders maintain their grasp and while the inner surfaces of the first and second holders are in the selected angular relationship to form a second multilayer article.

Abstract: The present invention provides a method for storing holographic data comprising providing an optically transparent substrate comprising a photochemically active dye; irradiating the optically transparent substrate with a holographic interference pattern, wherein the pattern has a first wavelength and an intensity both sufficient to convert, within a volume element of the substrate, at least some of the photochemically active dye into a photo-product, producing within the irradiated volume element concentration variations of the photo-product corresponding to the holographic interference pattern, thereby producing a first optically readable datum corresponding to the volume element; activating the optically transparent substrate to form an intramolecular hydrogen bond to a nitrone oxygen in residual photochemically active dye, to stabilize the optically readable datum.

Abstract: The invention provides a hologram transfer foil comprising a substrate and a transfer layer laminated thereon, said transfer layer comprising a surface protective layer, a thermoplastic resin layer, a hologram layer and a heat seal layer in this order. The hologram transfer foil is applied on the heat seal layer side to an application member. In this case, a peel force between the substrate and the surface protective layer is smaller than that between adjacent layers in other layers. This hologram transfer foil enables a hologram image, etc. to be reconstructed in an uninterrupted manner, and is improved in terms of transferability and productivity.

Abstract: A method for impressing holographic images or holograms in the surface of metal objects such as aluminum cans, sheet metal or metal foil. The surfaces of metal shims and print rolls bearing holograms are hardened as by coating them with thin amorphous diamond coatings or diamond like coatings so the holograms can be embossed into many thousands of metal objects with clarity and consistency.

Abstract: The present invention relates to a method and an apparatus for forming a hologram from a mask. According to the invention a photoresist is used as the holographic recording medium and the planes of polarisation of the object and reference beams incident on the holographic recording medium are arranged such that their polarisation vectors are substantially mutually orthogonal in the holographic recording medium and such that the polarisation vectors of the incident and totally internally reflected reference beams are also substantially orthogonal. Preferably, just the transmission hologram is formed in the holographic recording layer.

Abstract: There is provided an optical recording medium comprising a recording layer containing a charge-generating material capable of generating a first electric charge and a second electric charge by beam irradiation, the second electric charge having a different polarity from that of the first electric charge, a charge-transport material enabling at least the first electric charge to be transported to isolate the first electric charge and the second electric charge, and a trapping material retaining the first electric charge. The optical characteristics of the recording layer is changed in accordance with changes in spatial distribution of the first and second electric charges, and the trapping material is provided with a conjugated system and with at least one nitrogen-containing heterocyclic group, and bonded through an unsaturated carbon atom of the heterocyclic group to the conjugated system.

Abstract: A host matrix—normally a binder such as cellulose acetate propionate in a solvent such as acetone—contains a radiation-polymerizable photopolymer—normally a monomer like dipentaerythritol pentaacrylate in combination with a crosslinker like 1-vinyl-2-pyrrolidinone, an initiator like N-phenyl glycine, and/or a photosensitizer like camphor quinone—that is initially uniformly doped with a stable dye—typically Rhodamine B and/or Bodipy Red—that photoinitiates photopolymerization. Upon selective exposure of certain regions of the matrix by radiation, most normally laser light radiation, the dye will initially migrate and redistribute itself to radiatively-exposed regions until, dye migration being substantially complete, photopolymerization will occur, locking the migrated dye in place at a relatively higher concentration at the selectively exposed regions. The dye therein stably located can be optically detected by, preferably, light-radiation-stimulated fluorescence.

Abstract: The invention provides a hologram plate which is used with the double-focus replication process, and which is integrated with a spacer to impart marring resistance thereto, and is integrated with a light absorbing layer to allow zero-order light and first-order light to have substantially the same intensity. This hologram plate 42 comprises an array of collective element holograms for diffracting parallel light incident thereon at a specific wavelength and a specific incident angle in such a way that the light is converged onto a specific focal length position. The hologram plate 42 is a multilayer structure made up of a first transparent substrate 31, a hologram layer 32, an adhesive layer 33 and a second transparent substrate 41. The second transparent substrate 42 defines a surface in contact with a hologram photosensitive material 53 during hologram replication.

Abstract: Exemplary embodiments of the present invention provide a method of hologram exposure that is capable of making accurate alignment. A method of exposure according to one exemplary aspect of the present invention includes providing a mask for hologram exposure M2 including first alignment marks A1 through A4 that is readable with an alignment optical system 40 and a hologram exposure area D2 to which a hologram is recorded by hologram exposure so as to form a desirable coherent pattern and second alignment marks AL1 through AL4 on a substrate 10.

Abstract: The present invention relates to a method for producing an optical recording medium. In the method, on the surface of a recording layer formed by spin-coating a first coating solution containing a photo-isomerizable component, a second coating solution that contains a photo-isomerizable component that can be isomerized by radiation having the same wavelength as radiation used for isomerizing the photo-isomerizable component contained in the recording layer and incapable of dissolving the recording layer is spin-coated to form an intermediate layer. Since the intermediate layer thus formed cannot be dissolved by the first coating solution, a recording layer is further laminated on this layer. Thus, it becomes possible to make the recording layer thicker and also to provide a high-density recording characteristic.

Abstract: Pre-sensitization techniques can be used in conjunction with holographic recording materials to allow high quality holographic stereograms to be recorded in those holographic recording materials using pulsed lasers. Additional hologram production system hardware and software designs for use with pulsed lasers are disclosed.

Abstract: The present invention provides a volume type hologram recording photosensitive composition. A type (i) composition comprises one or more photopolymerizable compounds, a heat-curable compound and a heat-curing crosslinking agent, wherein the heat-curing crosslinking agent is a latent heat-curing crosslinking agent which is not reacted in an interference exposure process, is not reacted at the heating temperature used in a refractive index-modulation promoting process and becomes active at the heating temperature used in a heat-curing process. A type (ii) composition further comprises a binder resin beside the type (i) volume type composition.

Abstract: A method of writing an extended grating structure in a photosensitive waveguide comprising the steps of utilizing at least two overlapping beams of light to form an interference pattern, moving the waveguide through said overlapping beams, simultaneously controlling a relative phase delay between the beams utilising a phase modulator, thereby controlling the positions of maxima within said interference pattern to move at approximately the same velocity as the photosensitive waveguide, wherein the phase modulator does not comprise a mechanical means for effecting the phase modulation, and modifying the relative phase delay between the beams during the writing of the grating structure, whereby a deliberate detuning of the velocity of the positions of maxima within said interference pattern and the velocity of the photosensitive waveguide is utilized to vary a period of the written grating structure in the photosensitive waveguide.

Abstract: This invention relates to the field of holography, in particular to a method and a device for recording optical holograms by means of amorphous molecular semiconductor (AMS) films deposited on a glass substrate pre-covered with a transparent electric conducting sub-layer. More precisely, the invention relates to a method and device for registering optical holograms on AMS-films which operates in such a way that the AMS-films possess the maximum achievable information parameters: Holographic sensitivity, optimal spatial frequency of the transmitted characteristic, band parameters for the spatial frequencies of the transmitted characteristic, “signal-to-noise” ratio in the restored holographic image, reference and object beam intensities ratio during hologram registration, and cycling ability.

Abstract: A diffractive optical element such as a diffuser, diffraction grating, and/or hologram, can be manufactured by using a surface relief pattern on a surface of a surface relief tool. A layer of curable material is physically contacted with the surface relief pattern on the surface of the surface relief tool to thereby imprint the pattern on a surface of the layer. Diffractive features are formed in the layer by propagating energy through the surface relief tool and into the layer such that refractive index variations corresponding to the pattern are created in the layer. The resultant product is a diffractive optical element comprising a layer of material having diffractive features formed by a predetermined pattern of refractive index variations. The diffractive features originate at an undulating boundary and extend only from one side of the boundary into the material. The undulating boundary has an undulating pattern that corresponds to the predetermined pattern of refractive index variations.

Abstract: This invention relates to the field of holography, in particular to a method and a device for recording optical holograms by means of amorphous molecular semiconductor (AMS) films deposited on a glass substrate pre-covered with a transparent electric conducting sub-layer. More precisely, the invention relates to a method and device for registering optical holograms on AMS-films which operates in such a way that the AMS-films possess the maximum achievable information parameters: Holographic sensitivity, optimal spatial frequency of the transmitted characteristic, band parameters for the spatial frequencies of the transmitted characteristic, “signal-to-noise” ratio in the restored holographic image, reference and object beam intensities ratio during hologram registration, and cycling ability.

Abstract: Methods for producing a hologram mask approximating the exposure produced by a non-holographic phase shifting photo mask are disclosed. One such method exposes a hologram recording material to a first object light, having passed through a first original mask and a first reference light having a difference in phase with the first object light, and further exposing the hologram recording material to a second object light, having passed through a second original mask and a second reference light having a difference in phase with the second object light, wherein first and second phase differences are not the same and wherein the exposed hologram material can be replayed to produce an exposed pattern that approximates an exposed pattern of a non-holographic phase shifting photomask.

Abstract: The invention provides a hologram transfer foil (1) comprising, that includes, in order from top to bottom, a substrate (7), a volume hologram layer (2) releasably stacked on substrate (7) and comprising a volume hologram in a cured resin layer, a first heat seal layer (3) and a second heat seal layer (4). In use, the hologram transfer foil (1) is applied on the second heat seal layer (4) side over an application member. The adhesion force of volume hologram layer (2) to the application member is larger than a material fracture force for the volume hologram layer or the application member, so that the hologram transfer layer can be applied by thermo-compression to the application member. This hologram transfer foil is useful for illegal copying of the hologram layer because when the volume hologram is forcibly peeled from the application, a material fracture of the volume hologram layer or application member occurs.

Abstract: A method of fabricating a distributed feedback optical fiber laser, comprises the step of exposing an optical fiber (20) to a transverse light beam (30) to form a grating structure in a section of the optical fiber, the writing light beam being polarized in a direction not parallel to the axis of the section (10) of optical fiber (20).

Abstract: An optical recording material which when exposed to actinic radiation produces a change in optical properties in the exposed regions, thereby providing a pattern of intelligence for storing and retrieving information, the recording material having: a) a polymer containing a covalently bound reactant moiety which is capable of undergoing a chemical transformation upon a one electron oxidation, thus causing the change in optical properties in the exposed regions; and b) a sensitizer capable of absorbing actinic radiation to cause an initial one electron oxidation of the reactant.

Abstract: A method for patterning a layer on a substrate can include projecting coherent radiation toward a reflector surface so that the coherent radiation is reflected off the reflector surface to provide a holographic projection of a desired image wherein the reflector surface includes information that corresponds to an inverse of the holographic projection of the desired image. The substrate including the layer can be maintained in the path of the reflected radiation so that the holographic projection is projected onto the layer. Related systems are also discussed.

Abstract: A recording material for holograms includes a metal oxide porous body with an oxygen donor substance in the pores. In addition, a method manufactures a recording material for holograms that include a metal oxide porous body with an oxygen donor substance in the pores. The method includes forming a metal oxide porous body from a metal oxide precursor, and supplying an oxygen donor substance to the pores of the metal oxide porous body.