In recording technologies for batch formation of a plurality of recording bits in a recording medium by forming a plurality of optical spots using an ultrashort pulse laser and a spatial optical modulator, the batch recordable bit number has an upper limit, resulting in restricted recording speed. The intensity of the optical spot is corrected to increase the batch recordable bit number for increasing the recording speed.

Provided is an optical medium reproducing apparatus including: a detection unit that divides a luminous flux into a plurality of regions including a first region and a second region which are different in a position in a radial direction and/or a tangential direction, and combines a plurality of detection signals in correspondence with the amount of light that is incident to each of the plurality of regions with combination patterns which are selected to form signals of a plurality of channels; a multi-input equalizer unit that includes a plurality of equalizer units to which the signals of the plurality of channels are respectively supplied, computes outputs of the plurality of equalizer units, and outputs the resultant value as an equalization signal; and a binarization unit that performs binarization processing with respect to the equalization signal to obtain binary data. An addition signal channel including a constant multiplication of detection signals of the first region and the second region is included in at least one of the combination patterns.

Provided is an optical medium reproducing apparatus including: a detection unit that divides a luminous flux into a plurality of regions including a first region and a second region which are different in a position in a radial direction and/or a tangential direction, and combines a plurality of detection signals in correspondence with the amount of light that is incident to each of the plurality of regions with combination patterns which are selected to form signals of a plurality of channels; a multi-input equalizer unit that includes a plurality of equalizer units to which the signals of the plurality of channels are respectively supplied, computes outputs of the plurality of equalizer units, and outputs the resultant value as an equalization signal; and a binarization unit that performs binarization processing with respect to the equalization signal to obtain binary data. An addition signal channel including a constant multiplication of detection signals of the first region and the second region is included in at least one of the combination patterns.

Methods and systems for performing dynamic aperture holography are described. Examples include a method of recording multiple holograms in a photosensitive recording medium, where multiple signal beam angular apertures used to record the multiple holograms differ from each other. The multiple signal beam angular apertures can facilitate using a larger range of reference beam angular apertures. The multiple holograms are typically multiplexed, and examples of dynamic aperture holography enable packing the multiplexed holograms more densely in the recording medium. Some dynamic aperture holography systems include monocular objective lens architecture.

An optical information storage medium includes a substrate and a multilayer polymeric film. The multilayer polymeric film has a first surface and an opposite second surface that extend the length of the multilayer polymeric film. The second surface is adhered to a surface of the substrate. The multilayer polymeric film includes a plurality of coextruded alternating polymeric active data storage layers and polymeric buffer layers.

A reproduction apparatus dividing a cross section of superposed light into a plurality of regions in a tangential and/or radial direction includes: an optical system configured to generate each of a first set of signal light and reference light having a phase difference of approximately 0°, a second set of signal light and reference light having a phase difference of approximately 180°, a third set of signal light and reference light having a phase difference of approximately 90°, and a fourth set of signal light and reference light having a phase difference of approximately 270°, using a plurality of superposed light beams corresponding to the divided regions; an optical receiver configured to output signals corresponding to the sets of the signal light and the reference light; and a circuit configured to compute signals as differences between the signals, and obtain a reproduction signal by computation from the computed signals.

According to a positioning method for a hologram in a disk-type holographic storage medium, a guide groove is formed in advance in the disk-type storage medium and is scribed with a positioning marker that includes index information, position information and crossing angle information. The positions of a positioning laser beam and a recording/reproducing laser beam are applied to the same medium position. When an optical head accesses a recording/reading position at a high speed, the shift multiplex recording/reading is performed starting from a marker position. A servo system controls the laser beams to move along the guide groove and ensures that a focused beam is focused on the medium. According to the method, the position and angular information can be quickly positioned in process of performing cross-shift multiplex recording/reading, the recording/reading speed of the system is improved, and random access is achieved.

A reproduction apparatus dividing a cross section of superposed light into a plurality of regions in a tangential and/or radial direction includes: an optical system configured to generate each of a first set of signal light and reference light having a phase difference of approximately 0°, a second set of signal light and reference light having a phase difference of approximately 180°, a third set of signal light and reference light having a phase difference of approximately 90°, and a fourth set of signal light and reference light having a phase difference of approximately 270°, using a plurality of superposed light beams corresponding to the divided regions; an optical receiver configured to output signals corresponding to the sets of the signal light and the reference light; and a circuit configured to compute signals as differences between the signals, and obtain a reproduction signal by computation from the computed signals.

An optical disk (100) of the present invention includes (i) a medium information region (101) (a) in which type identification information is recorded by recesses and/or protrusions which are formed by a given modulation method and whose lengths are longer than a length of an optical system resolution limit of a playback device and (b) in which first address information is recorded in a first address data format and (ii) a data region (102) (a) in which content data is recorded by recesses and/or protrusions which are formed by the given modulation method and which include a recess and/or a protrusion whose length is shorter than the length of the optical system resolution limit and (b) in which second address information is recorded in a second address data format.

An optical information storage medium includes a substrate and a multilayer polymeric film. The multilayer polymeric film has a first surface and an opposite second surface that extend the length of the multilayer polymeric film. The second surface is adhered to a surface of the substrate. The multilayer polymeric film includes a plurality of coextruded alternating polymeric active data storage layers and polymeric buffer layers.