Abstract: The present invention relates to a powdery photosensitive material comprising evenly dispersed components and free from a variation in quality, and an optical recording medium produced from the photosensitive material. The photosensitive material is produced by a process including freezing a solution of components that constitutes the photosensitive material dissolved in a first solvent and then drying the resultant solid under reduced-pressure.

Abstract: An optical recording medium has a transparent substrate having a first surface and a second surface, a recording layer provided on the first surface of the substrate and on which a light beam is incident to record information as a hologram, and a servo layer provided on the second surface of the substrate and including a phase change layer in which servo information is recorded as a phase change. The servo information is recorded as changes in the phase of the phase change layer.

Abstract: An optical recording medium includes: a recording layer containing a photopolymerization initiator and a photopolymerization compound; and a pigment that generates light through a multiphoton absorption process.

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: An optical-information recording medium includes a substrate that includes a servo surface having a servo pattern thereon; an information recording layer laminated on the servo surface of the substrate capable of recording information as a hologram produced by interference between an information beam containing the information and a reference beam; an address servo area that is formed as a part of the servo pattern, and that records therein address information and clock information for aligning a beam, emitted from an optical-information recording apparatus for recording information in the information recording layer, to a target position in the information recording layer; and a following up servo area that is formed as a part of the servo pattern, and that is to be irradiated by the beam to make the beam follow a rotation of the optical-information recording medium.

Abstract: A holographic recording medium includes a recording layer containing a matrix material, a photoactive monomer having an ethylenic unsaturated bond dispersed in the matrix material and a photoinitiator, and a polymerization-terminating layer formed on at least one surface of the recording layer.

Abstract: An optical-information recording medium includes a substrate that includes a servo surface; an information recording layer laminated on the servo surface of the substrate capable of recording information as a hologram produced by interference between an information beam containing the information and a reference beam; a tracking servo area that is formed in a track direction on the servo surface, and that records therein tracking information for tracking servo control; and a following up servo area that is formed in the track direction on the servo surface, and that is to be irradiated by a beam emitted from an optical-information recording apparatus for recording the information in the information recording layer so as to make the beam follow a rotation of the optical-information recording medium.

Abstract: A holographic recording medium has a recording layer, including a matrix formed of a polymer of spiroorthoester of an epoxy compound, a radical-polymerizable compound, and a photoinitiator.

Abstract: Disclosed is a recording medium comprising a recording layer including a photo-acid generating agent that generates an acid upon irradiation with an actinic radiation and a polymer having a polymerizable substituent group bonded to a main chain of the polymer via a functional group that cleaves in the presence of the acid.

Abstract: An optical disk recording apparatus and method utilize a recording beam source, a spatial light modulator that modulates a recording radiation beam into an information beam carrying information and a reference beam, a focusing unit that focuses the information beam and the reference beam onto an information recording layer, an image sensing device that detects intensity distribution of the information beam, and a control unit. The control unit controls the spatial light modulator on the basis of the intensity distribution detected by the image sensing device. An optical disk recording apparatus, and a control method thereof, thereby has a high signal-to-noise ratio.

Abstract: An optical disk recording apparatus and method utilize a recording beam source, a spatial light modulator that modulates a recording radiation beam into an information beam carrying information and a reference beam, a focusing unit that focuses the information beam and the reference beam on an information recording layer, an image sensing device that detects the intensity distribution of the information beam, and a control unit. The control unit controls the spatial light modulator on the basis of the intensity distribution detected by the image sensing device. A recording/reproducing apparatus can check the amount of information capable of being recorded onto an optical disk, and an optical disk therefor.

Abstract: A method for storing holographic data in a medium having a reflection layer and a recording layer comprises: recording, rotating and repeating. An interference pattern is recorded at a recording position of the recording layer of the medium in a stationary state. The interference pattern is formed by an interference between an object beam and a reference beam which are irradiated into the recording layer from an opposite side of the reflection layer. The medium is rotated so as to shift the recording position by a distance of n×Sh where n is a positive integer and Sh is a predetermined recording shift amount. The recording and the rotating are repeated alternately.

Abstract: A holographic recording medium has a recording layer, the recording layer including a matrix material, a polymerizable monomer having at least one ethylenic unsaturated bond, a photo-iniferter, and a photoinitiator.

Abstract: An optical recording medium is provided and includes: a recoding layer; and a reproduction control layer on an light incidence side of the recording layer, the reproduction control layer including a photopolymerization initiator and a photopolymerizable compound.

Abstract: A holographic recording medium has a recording layer including a radical-polymerizable compound, a first photo-radical polymerization initiator (A) containing a titanocene compound, and a second photo-radical polymerization initiator (B) containing at least one compound selected from the group consisting of an amino acetophenone derivative, an acylphosphine oxide derivative, a benzyl derivative, and a thioxanthone derivative.

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 method of holographic recording and reproduction includes recording to the holographic recording medium a wavelength variation reference pattern which is recorded as a hologram at a wavelength of the recording beam, recording to the holographic recording medium a page data pattern as a hologram at the wavelength of the recording beam, detecting the wavelength variation between the recording beam and the reproducing beam based on the size of an image for wavelength variation reference obtained by reproducing the wavelength variation reference pattern at a wavelength of the reproducing beam, and reproducing the page data pattern using the reproducing beam with a wavelength controlled based on the detected wavelength variation.

Abstract: A holographic recording medium includes a transparent layer having a servo surface and a light incidence surface which face each other; a reflecting layer formed on the servo surface-side transparent layer; and a holographic recording layer formed on the light illuminating-side transparent layer. The transparent layer includes resin films laminated so that adjacent resin films differ in stretching direction by 90 degrees.

Abstract: The present invention relates to a method for optical recording in which information is recorded on an optical recording media utilizing holography and to a method for optical reproducing in which information recorded on an optical recording media utilizing holography is reconstructed. The methods includes preparing an optical recording media having wavelength reference marks with a periodic structure which are associated with a recording base wavelength, irradiating the wavelength reference marks with a beam from a light source on recording information or on reproducing information to detect a wavelength shift of the light source with respect to the base wavelength based on a diffraction beam from the wavelength reference marks, and performing recording or reproducing while controlling the wavelength of the light source so as to reduce the wavelength shift.

Abstract: A holographic recording medium includes a transparent layer having a servo surface and a light incidence surface which face each other; a reflecting layer formed on the servo surface-side transparent layer; and a holographic recording layer formed on the light illuminating-side transparent layer. The transparent layer includes resin films laminated so that adjacent resin films differ in stretching direction by 90 degrees.