摘要:
A holographic recording medium in which a thick holographic recording layer is formed without the use of multilayering and without accompanying thickness unevenness, scattering, and nonuniformity of dynamic range, and a method for manufacturing the same. The holographic recording medium 10 is configured by sandwiching a hybrid material layer 14 and a photopolymer layer 16 between first and second substrates 12 and 18. The hybrid material layer 14 contains an inorganic glass and a photopolymer as main ingredients. The photopolymer layer 16 subjected to heat or ultraviolet curing is provided on the dried hybrid material layer 14 such that the combined thickness of this hybrid material layer 14 and the photopolymer layer 16 is uniform. The second substrate 18 is bonded and fixed to this photopolymer layer 16 serving as a bonding layer.
摘要:
A method and apparatus for performing reproduction position servo-control without reducing the recording capacity of a holographic recording medium. Upon the reproduction of a holographic recording medium 18, part of a reproduction beam serving as a servo beam is projected onto a recording layer 18A of the holographic recording medium 18 from the side opposite to the side of the reproduction beam (a reference beam) along the same optical axis as that of the reproduction beam, and the diffraction beam thereof is detected by a photodetector 26C through a polarizing beam splitter 26B.
摘要:
A holographic recording method and apparatus capable of performing phase code multiplex recording without employing a phase spatial light modulator. The holographic recording apparatus 10 performs phase spatial modulation of a reference beam to be projected onto a holographic recording medium by means of a phase code mask 26 in which phase code patterns are recorded in advance as a hologram and which is employed in place of a phase spatial light modulator in a reference optical system 20.
摘要:
In a holographic recording medium, noise is prevented from being generated by servo light in a recording layer without scarifying recording regions. A holographic recording medium 12 has a servo layer 16 formed on a recording layer 14 on a substrate 13 via a spacer layer 15. The servo layer 16 reflects the servo light and has one of wavelength selectivity and incident angle selectivity each of which allows object light and reference light to pass through.
摘要:
A holographic recording medium which has parallelism of high precision and causes little substrate deformation ascribable to contraction of its recording areas when recording interference fringes, and a method for manufacturing the same. The holographic recording medium has a holographic recording material layer between a first transparent substrate and a second transparent substrate. This holographic recording material layer is formed integrally with a spacer which is composed of a large number of spherical beads arranged so as to surround recording areas for interference fringes to be recorded on.
摘要:
There are provided a holographic recording method, a holographic recorder, a holographic recording/reproducing method, a holographic recorder/reproducer and a holographic recording medium as follows. Information is angle-multiplex-recorded as a hologram by a first format in which one of a signal light and a reference light branched from a laser light source intersects the other at a specified incident angle in a recording layer and the incident angle is altered at a specified angular pitch or a second format having a higher angle selectivity. When information is recorded in the second format having a higher angle selectivity, the incident angle can be adjusted to include such an incident angle that satisfies Bragg's conditions at the time of recording in the first format and compatibility of reproduction can be ensured between media having different angle selectivity.
摘要:
In a personal identification system 10 for identifying a user on the basis of biometric information, a hologram is formed in a holographic recording portion 13 of an optical information recording medium 12. The hologram is provided by the interference between a reference beam subjected to spatial light modulation by record cryptographic identification information based on the biometric information of the user obtained by a biological information sensor 14 and an object beam. At the time of identification, an information processing device 16 makes validation cryptographic identification information from the biometric information directly obtained from the user, and a spatial light modulator 20 modulates a hologram reproduction reference beam by the validation cryptographic identification information. The right or wrong of a reproduced image is detected, and the leakage of the identification information is prevented.
摘要:
A holographic recording apparatus 10 realizes multilevel gray-scale recording by: controlling a reflection type spatial light modulator (DMD 18D) via a control unit 24 so that an object beam in an object optical system 18 is reflected in an exposure direction so as to be incident on a holographic recording medium 16 or in a non-exposure direction so as not to be incident thereon selectively pixel by pixel in accordance with a data page to be recorded; and making (N+1) levels of gradation exposure with a single exposure time t1 given by dividing t0 by N, where to is an exposure time necessary for rendering a single pixel of the data page as an ON pixel, and N is an integer of not less than 2.
摘要:
A holographic recording and reproducing apparatus 10 can simultaneously reproduce a plurality of data images by the single application of a reproduction reference beam in reproducing holograms. In the holographic recording and reproducing apparatus 10, an object beam is projected from a fixed object beam incident optical axis 18A to a holographic recording medium 16, and a reference beam is incident on the holographic recording medium 16 selectively from a plurality of incident optical axes 38A to 38C by modulating the angle of a rotating mirror 32 in many stages. A rotating stage 36 rotates the holographic recording medium 16 in such a manner that the holographic recording medium 16 has a constant angle with respect to the reference beam selectively incident thereon via each incident optical axis 38A, 38B, or 38C. When reproducing data images, the projection of a single reference beam generates a plurality of diffracted light beams in different directions in response to the rotational angle of the holographic recording medium 16 at the time of recording, and three imaging devices 22A, 22B, and 22C simultaneously receive the diffracted light beams.
摘要:
A multilayer holographic recording medium in which a recording density and a data transfer rate are largely improved, a manufacturing method of the same, a multilayer holographic recording and reproducing method, a multilayer holographic memory reproducing apparatus, and a multilayer holographic recording and reproducing apparatus are provided. A multilayer holographic recording medium 10 from which information is reproduced by a multilayer holographic memory reproducing apparatus 36 includes a plurality of deposited holographic recording layers 14A, 14B, 14C, . . . . During recording, a reference beam is common to those holographic recording layers and an incident angle of an object beam is modulated for each holographic recording layer. During reproduction, a laser beam for reproduction having the same condition as that of the reference beam used for recording is projected thereonto, so that diffraction beams are simultaneously generated in the respective holographic recording layers 14A, 14B, . . . to directions that are the same as incident directions of the object beam used for recording.