805 results about "Holographic recording" patented technology

A holographic recording medium exhibiting a high recording sensitivity without execution of reduction treatment. A system records information on the holographic recording medium by using a gating light within a wavelength band causing less optical damage to the holographic recording medium. The holographic recording medium includes a single crystal of lithium niobate (LiNbO3) or lithium tantalate (LiTaO3) containing Mn as a dopant.

A method for the production of a holographic sensor wherein the holographic recording material forming the sensitive element is a polymer matrix, which comprises diffusing into the matrix one or more soluble salts that undergo reaction in situ to form an insoluble sensitive precipitate; and recording a holographic image. This method allows the production of a holographic sensor wherein the holographic recording material forming the sensitive element is an insoluble polymer film.

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.

A holographic recording and reconstructing apparatus includes a light source having a variable oscillation wavelength; a temperature sensing unit operable to sense temperature; and a control unit operable to record information about a temperature sensed by the temperature sensing unit on a holographic recording medium during recording, to obtain the information about the temperature from the holographic recording medium and obtain a temperature sensed by the temperature sensing unit during reconstruction, to determine the amount of wavelength shift to counteract the effects of a change in the dimension of the holographic recording medium between recording and reconstruction based on the difference between the temperatures, and to shift the oscillation wavelength of the light source by the determined amount.

A holographic recording apparatus having a source of illumination, a master hologram containing at least one hologram lamina overlaying, a copy substrate containing a holographic recording medium, and a voltage generator for applied a voltage across at least one of the master hologram and the copy substrate. The master hologram diffracts the illumination light into zero order light and diffracted light which interfere in the copy substrate to form a copy of the master hologram. The source of illumination is applied for a predefined exposure time during which the voltage varies the refractive index modulation of at least one of the master hologram and the copy hologram.

An apparatus for writing and reading holograms, comprising a spatial light modulator (SLM) operable in phase mode, having a plurality of pixels for generating an object beam that overlaps with a reference beam; a holographic recording medium (HRM) in the path of the object beam; and a first lens element disposed in the path of the object beam between the SLM and the HRM; wherein the HRM is disposed at or near the Fourier transform plane of the first lens element.

Calibration of holographic data storage systems (HDSS) is provided by utilizing holographic media (4) having calibration features which can be read, written, or read and written by a HDSS (30). Calibration features may represent for example, surface-relief gratings, holographic recordings, amplitude varying regions, or magnetic regions, or a combination thereof, at locations on or within the media. One or more of the calibration features along media region (302) are media calibration features with media and format information, and other calibration features along region (301) are system calibration features for optically and mechanically aligning HDSS optics. The media (4) may have performance calibration features along region (307) which can be recorded by a HDSS and then read back to determine characteristics of the media. Different HDSS systems can read the calibration features of the media (4) when installed in each HDSS to obtain information about the media, and to optically and mechanically align the media for optimal operation with the media.

The present invention relates to a system, as well as articles and holographic recording medium comprising the system, where the system comprises: a polymerizable component comprising at least one photoactive polymerizable material; and a photoinitiator component comprising at least one photoinitiator for causing the polymerizable component to polymerize to thereby form a plurality of holographic gratings when activated by exposure to a photoinitiating light source; wherein when a portion of the polymerizable component has been polymerized to form at least one holographic grating, the unpolymerized portion of the polymerizable component is resistant to further polymerization when not exposed to the photoinitiating light source. The present invention also provides methods for forming at least one holographic grating in a holographic recording medium having such a photopolymerizable system.

A method of recording an object image of a first hologram as a second hologram is provided. A first hologram is recorded at a first angle of reconstruction and a holographic recording medium is provided. An object beam is directed through the first hologram at the first angle of reconstruction to reconstruct the object image on the recording medium. The recording medium is struck with a reference beam at a second angle of reconstruction to form a wave interference pattern with the object beam. The second angle of reconstruction is between 45 and 90 degrees. The wave interference pattern is recorded. A switch is provided that includes a hologram that has an angle of reconstruction between 45 and 90 degrees. A reproducing light source is positioned to direct light through the hologram at the angle of reconstruction to form a holographic image at a predetermined distance from the hologram. The switch includes a detector that detects the presence of an object proximate to the holographic image. The axis of the detector beam source is not perpendicular to the plane of the medium to which its hologram is affixed.

A hologram recording medium has a transparent substrate having an incidence surface, on which a write beam and a reference beam are made incident, and a servo surface opposite to the incidence surface, the servo surface including a header section and a data section, a reflecting layer formed on the servo surface of the transparent substrate, and a hologram recording layer provided on the incidence surface of the transparent substrate, the servo surface having intermittent tracking grooves in the data section except for recording positions, and a width of the tracking grooves being set at a value to less than an e−2 diameter of the reference beam.

A novel polymerizable high-refractive index compound which is useful as an optical material, and a holographic recording medium using the same, which has high diffraction efficiency, high light transmittance and small rate of shrinkage, are provided. A composition for forming a holographic recording layer containing a reactive compound represented by the following formula 1, a holograph recording material, and a holographic recording medium provided with a recording layer containing the same, are disclosed.(In the formula (1),A is an optionally substituted ring;Ar is an optionally substituted (hetero)aryl group formed by condensation of two or more rings;R is hydrogen or a methyl group;n is an integer of from 1 to 7; andwhen n is 2 or more, then plural Ars may be the same as or different from each other,provided that when A is an aromatic heterocyclic ring, and Ar is an optionally substituted (hetero)aryl group formed by condensation of two or more rings, then in the structure in which A and Ar are connected with each other, those partial structures that are in the structure of each of A and Ar, and are connected directly with each other, do not contain a heteroatom.)

According to one aspect and example, a holographic recording system includes a light source, an object for modulating an object beam from the light source, and a relay system adapted to magnify (positive or negative) the modulated beam (e.g., an image of the object) to an output image. The object may include an SLM operable to modulate the object beam with an information layer comprising a plurality of data pages. The output image is directed to the holographic storage medium, where a reference beam is also directed, to record the resulting interference pattern. Additionally, the relay system converges the output image to an output Fourier plane, which may be disposed within the holographic storage medium. A filter may be placed at an intermediate Fourier plane located prior to the output Fourier plane, and a phase mask may be placed at the position of the output image.

The present invention discloses a new class of triarylsulfonium salt photoacid generators (PAGs), which are thermally stable and can be activated by long wavelength UV or visible light. The sulfonium PAGs of the present invention are additionally soluble in monomers that can be polymerized by cationic polymerization chemistry, and mixtures of said sulfonium PAGs and monomers can be stored for long periods of time without undergoing polymerization. Furthermore, typical holographic recording media comprising one of these sulfonium PAGs, polymerizable monomer(s), a sensitizing dye, and a binder can be stored for long periods of time without exhibiting significant loss of recording sensitivity. Preferred sulfonium PAGs of the present invention are sulfonium PAGs substituted with one or more fluoro or fluoroalkyl groups.

A holographic recording medium provided with a holopraphic recording layer containing a binder forming compound, a compound provided with an ethylenical unsaturated bond, a photopolymerization initiator which can initiates a polymerization reaction of said compound provided with an ethilenical unsaturated bond, and a sensitizing dye which can spectrally sensitize a photopolymerization initiator, wherein said binder forming compound contains specific compound combination.

According to one aspect, methods and systems for recording and reading holographic storage media are provided. In one aspect, a method includes illuminating a data mask with a beam and recording a resulting modulated beam in a holographic storage medium, wherein the data mask includes an information layer that is divided into multiple data pages, and propagating a reference beam to the holographic storage medium to record the multiple data pages of the data mask in a parallel fashion on the holographic storage medium.

The present invention relates to a system, as well as articles and holographic recording medium comprising the system, where the system comprises: a polymerizable component comprising at least one photoactive polymerizable material; and a photoinitiator component comprising at least one photoinitiator for causing the polymerizable component to polymerize to thereby form a plurality of holographic gratings when activated by exposure to a photoinitiating light source; wherein when a portion of the polymerizable component has been polymerized to form at least one holographic grating, the unpolymerized portion of the polymerizable component is resistant to further polymerization when not exposed to the photoinitiating light source. The present invention also provides methods for forming at least one holographic grating in a holographic recording medium having such a photopolymerizable system.

The present invention provides a hologram recording material which is not required to be subjected to pre-exposure treatment at the time of recording, attains high refractive index change, high sensitivity, low scattering, environment resistance, durability, low dimensional change, and high multiplicity, and is suitable for volume hologram recording. Also, the present invention provides a hologram recording medium. A hologram recording material comprising a matrix material having a softening temperature of 50° C. or higher, and a photopolymerizable monomer which is in a liquid phase state at room temperature. The matrix material is preferably contained in an amount of 50% by weight or more and 90% by weight or less of the whole of the hologram recording material. A softening temperature of the hologram recording material is preferably 0° C. or higher.

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.

While Fourier transformation of a signal light beam is performed to perform recording during holographic recording so that a focal point is formed outside a holographic recording layer (defocus recording), an aperture is arranged on an outgoing side of the reproduced signal light beam (reproduction light beam), the reproduction light beam is focused at the aperture, and low-order components of a Fourier transform image of the reproduction light beam are selectively transmitted to detect only the transmitted light beam. Therefore, information recorded as the hologram in the holographic recording layer can be reproduced with high S / N ratio from the holographic recording layer added onto a support body, particularly onto a sheet member having non-optical quality such as paper and a plastic card.

To provide a composition for a hologram recording material, a hologram recording material and a hologram recording method applicable to a high density optical recording medium, a three-dimensional display, a holographic optical element etc. and capable of attaining a high sensitivity, a high diffraction efficiency, a satisfactory storage property, a low shrinkage rate, a dry process, a multiplex recording property and a high recording density. An unrewritable hologram recording method including a step in which a sensitizing dye absorbs light by an exposure to form an excited state, a chemical reaction step including a color forming reaction involving an electron transfer or an energy transfer from such excited state, and a hologram-forming step by such chemical reaction.

A method for producing holograms with a multiplicity of holographic prescriptions from a single master is provided. A multiplicity of holographic substrates each having a first hologram is stacked on a second holographic recording medium substrate. The first hologram is designed to diffract light from a first direction into a second direction. When expose to illumination from the first direction zero order and diffracted light from each first hologram interfere in the second holographic recording medium substrate forming a second hologram. The second hologram is then copied into a third holographic recording medium substrate to provide the final copy hologram.

Hologram recording devices and techniques can be employed to produce wide-field-of-view holograms. In one embodiment, a specialized lens is used to couple an object beam into a holographic recording material without substantially changing the angle of incidence of the object beam. When displayed, images from holograms recorded using technique can have a field-of-view greater than that of the object beam. In another embodiment, one or more aspheric reflective surfaces are used to couple an object beam into a holographic recording material at relatively steep angles.

A holographic recording medium having a polymer matrix comprising a developer, wherein the holographic recording medium is capable of recording a latent hologram and the developer is capable of developing the latent hologram into a readable hologram by activation of the developer is disclosed. The holographic recording medium is capable of storing large numbers of holograms in the same volume with better signal resolution than previous holographic media by first recording a multitude of latent (or very weak) holograms in the same volume of space, then applying preferably a non-chemical fixing step to develop the latent holograms into readable holograms. The holographic recording medium and method of this invention cause the holograms to increase in diffraction efficiency, thus preventing complications caused during recording of holograms whereby previously recorded holograms interfere with latter recorded holograms in the same volume of space within the media.

A method of fabricating a holographic mask includes the steps of providing an illumination source and a non-opaque object mask. The source is for generating a coherent illumination beam directed along an axis. The object mask is capable of transmitting a portion of the illumination beam as undiffracted reference wavefronts. The object mask has one or more substantially transparent elements for creating overlapping object wavefronts when the illumination beam is incident thereon. The object mask is disposed in the illumination beam. A holographic recording medium is provided in the illumination beam in line optically with the object mask. The object mask is illuminated with the illumination beam, thereby causing the object mask to allow undiffracted reference wavefronts to pass therethrough. The illumination directed along the axis causes the one or more substantially transparent elements to create object wavefronts which interact with the undiffracted reference wavefronts to create an interference pattern.

The present invention relates to an article comprising: a pair of substrates comprising a thermoplastic; a holographic recording medium positioned between the substrates such that the holographic recording medium has at least one exposed area; and an environmental barrier seal protecting the at least one exposed area from environmental degradants; wherein the environmental barrier seal comprises: an inner layer adhered to at least one of the substrates and comprising a thermally meltable adhesive; an outer layer comprising a moisture impervious plastic; and an intermediate layer positioned between the inner and outer layers and comprising an moisture and oxygen impervious metallic foil. The present invention also provides a process for forming such an article.

The present invention provides a hologram recording medium which can attain high refractive index change, flexibility, high sensitivity, low scattering, environment resistance, durability, low dimension change (low shrinkage) and high multiplicity in holographic memory record using a blue laser. A hologram recording medium (11) comprising at least a hologram recording material layer, wherein the hologram recording material layer (21) comprises at least a metal oxide and a photopolymerizable compound; and said hologram recording medium has a light transmittance of 50% or more at a wavelength of 405 nm, or a light reflectance of 25% or more at a wavelength of 405 nm.

A device comprising an authentication hologram recorded within a defined volume of a holographic recording medium, wherein the authentication hologram is configured to convey authentication information; wherein the authentication hologram comprises a plurality of related volumetric holograms recorded within the defined volume; and wherein the holographic recording medium comprises an optically transparent plastic material and a photochemically active dye. In one embodiment, all the holograms are identical. In one embodiment, the holograms are different.