Abstract: An optical information recording/reproducing apparatus and an optical information recording/reproducing method that record information using holography, wherein the optical information recording/reproducing apparatus includes a signal generation unit that generates two-dimensional data by a two-dimensional encoding method in which a lower-limit value of a number of continuous ON/OFF pixels in an array in one direction of pixels in a two-dimensional spatial light modulator is K(K?2, K: natural number); and a pickup that records the two-dimensional data, generated by the signal generation unit, on a hologram disc.

Abstract: An apparatus and method for recording a micro-hologram are provided. The micro-hologram recording apparatus includes a first light source configured to emit a first light, the first light being coherent, a first optical system configured to divide the first light into a signal beam and a reference beam, and supply the signal beam and the reference beam to a location on a hologram recording medium, a second light source configured to emit a second light, the second light being incoherent and not interfering with the signal beam and the reference beam, and a second optical system configured to supply the second light to the same location as the signal beam and the reference beam on the hologram recording medium.

Abstract: In order to record an interference fringe pattern in a recording layer of a medium, a plurality of laser beams are caused to interfere so as to form interference fringes in the recording layer; and during a time period over which the plurality of laser beams are caused to interfere, the following steps are continuously performed: (1) producing a signal varying according to a shift of a specific position in the recording layer; and (2) shifting a fringe-forming position in the recording layer by changing a phase of at least one of the laser beams or moving the recording layer based upon the signal produced in the step (1).

Abstract: An acoustic hologram imaging system constructed from a machined housing having folded optics. Various surfaces of the housing are machined to provide a precise alignment to the optical members to be connected thereto, such as a mirror, a lens assembly, a light emitting laser diode, a camera, and the like. A three-part lens is described having different materials with different indexes of refraction in order to provide a desired focus of the light. In addition, an optical spatial filter is disclosed in which, according to various embodiments, all, some, or none of the light passing therethrough is attenuated for recording of the optical image of the hologram.

Abstract: There is provided an optical pickup including: an optical-system having an object-lens illuminating a first light for information recording or reproducing on a recording layer as a target and a second light on an optical-recording medium including a reference plane having a reflection-layer and the recording-layer at a layer position different from that of the reference-plane and on which information recording is performed through mark formation, and a focus-aligned-position-adjusting unit adjusting a focus-aligned position of the first light through the object-lens by changing collimation thereof incident to the object-lens; and a focusing-mechanism driving the object-lens in a focusing direction, wherein, when a depth of focus ?/NA2 defined by a wavelength ? of the first light and a numerical aperture NA of the object lens is set to ? and the maximum-surface-blur range is denoted by D, the optical-system is designed so that a use magnification ratio ? satisfies |?|??(D/?).

Abstract: A method and apparatus to control a position in which data is to be recorded on a holographic data recording medium by using interference between a reference light and a signal light, the method including: irradiating the reference light and the signal light on the holographic data recording medium; generating a focus error signal that indicates a distance difference between a first focus corresponding to a focus of the reference light on the holographic data recording medium and a second focus corresponding to a focus of the signal light on the holographic data recording medium, based on information about a reflective signal light generated when the irradiated signal light is reflected from a reflective transmission layer of the holographic data recording medium; and moving the second focus to a position of the first focus, based on the focus error signal.

Abstract: Techniques are provided for increasing storage capacity in a holographic storage system. While typical holographic storage systems involve binary storage for each data position in a holographic disk, present techniques involve storing data such that more than two data levels may be recorded in each data position. In some embodiments, a recording beam directed to the disk may be adjusted to different power levels depending on the data level to be recorded. Furthermore, the recording time at a data position may be adjusted to increase the energy directed to the data position by increasing the amount of time the recording beam is impinged on the data position. Embodiments are suitable for different types of holographic storage, including dye-based medium.

Abstract: A system and method for replicating optical data storage discs (e.g., holographic data storage discs) having multiple layers of data. Master discs providing for respective single layers of data are utilized, and each respective single layer of data from the master discs are replicate onto the optical data storage disc.

Abstract: An optical information recording/reproducing apparatus using holography comprises a signal generation unit that modulates input data, adds at least one control bit to each group of N bits, performs an NRZI-modulation on the modulated data, determines the at least one control bit such that a digital sum value of the NRZI-modulated data is 0, performs NRZI modulation on the data whose at least one control bit was determined, and rearranges the data to generate 2-dimensional data; a pickup that records the 2-dimensional data in a hologram disc and reproduces the 2-dimensional data from the hologram disc; and a signal processing unit that corrects the 2-dimensional data reproduced by the pickup, performs NRZI-modulation on the 2-dimensional data that has undergone a binarization operation, removes the at least one control bit added during the recording, and demodulates the data according to a modulation rule used during the recording.

Abstract: In case of reproducing a hologram recorded on an optical information recording medium, adjusting beam with the amplitude distribution and phase distribution at least partially the same as those of a signal beam upon recording is radiated to the optical information recording medium which records information. The diffracting beam diffracted by the hologram is detected by a photodetector. Based on the detected information, an incident angle of the reference beam to the optical information recording medium is appropriately controlled.

Abstract: A modular routing node includes a single input port and a plurality of output ports. The modular routing node is arranged to produce a plurality of different deflections and uses small adjustments to compensate for wavelength differences and alignment tolerances in an optical system. An optical device is arranged to receive a multiplex of many optical signals at different wavelengths, to separate the optical signals into at least two groups, and to process at least one of the groups adaptively.

Abstract: The present techniques provide methods and systems for reading and processing a data signal read from an optical data disc. In embodiments, an optical reader system may read data bits from a data ring in the disc. The data rings may be concentric, and a beginning of a sequence of data on the data ring may be in substantially the same position as an ending of the sequence. The reader may identify a data ring and begin the read process on the targeted data ring, and may end the read process when the reader reaches the starting point. The data sequence read from the data ring may be decoded to form a bit stream, which may be provided to various output devices. A circular trellis formed from the bit stream may enable the reading of a targeted data sequence without additional tail bits to improve data transmission efficiency.

Abstract: A method for irradiating a medium with a wave which is designed to focus on a particular portion in the medium, the method includes: irradiating the medium with an electromagnetic wave which is scattered in the medium, and is not designed to focus on the particular portion in the medium; detecting a first signal caused by irradiating the medium with the electromagnetic waver; irradiating the medium with a reconstructed wave which is designed to focus on the particular portion in the medium; detecting a second signal caused by irradiating the medium with the reconstructed wave; and monitoring, based on the first and second signals, that the particular portion is irradiated by the reconstructed wave.

Abstract: Methods and systems are provided for recording micro-holograms in a holographic disk. Disk tilting or disk imperfections may cause counter-propagating recording and reference beams to deviate from the target data position in the disk. In some embodiments, a tracking beam is directed to a tracking position in the disk, and deviation of the tracking beam from the tracking position may indicate tracking and/or focusing errors of the recording and/or reference beams. A detector may generate an error signal in response to such errors. A first servo-mechanical system may actuate a first optical head (e.g., transmitting the reference and tracking beams) to compensate for such errors, and a second servo-mechanical system may actuate a second optical head (e.g., transmitting the recording beam) to follow the actuation of the first servo system, such that an interference of the reference beam and the recording beam may be maintained in the target data position.

Abstract: An optical pick-up is provided. The optical pick-up includes a light source, a first objective lens configured to focus light emitted from the light source on a high-density optical information storage medium, a photo-detector configured to detect a signal by receiving light reflected from the high-density optical information storage medium, an optical-path changer configured to convert a travel path of incident light to allow the light emitted from the light source to proceed toward the high-density optical information storage medium, and to allow the light reflected from the high-density optical information storage medium to proceed toward the photo-detector, and a blocking device disposed in an optical path of signal light reflected from a target reproducing/recording layer of the high-density optical information storage medium, passes through the first objective lens, and proceeds toward the photo-detector.

Abstract: The optical information recording and reproducing device utilizing holography requires the optical system to generate the signal beam and the reference beam to be irradiated to the holographic storage medium as well as another optical system to generate the curing light beam to be irradiated to the holographic storage medium. Furthermore, from the viewpoint of backward compatibility, if the same device is used for recording or reproduction on the conventional optical discs represented by Blu-ray Disc, another optical system adaptable to recording and reproduction on these optical disks is required. This means the optical system configurations become complicated and larger in size. One solution for downsizing is to use the reference beam also as the curing light beam. Another way is sharing of optical path for curing light beam and for the reference beam. Furthermore, it is possible to share the light source for generating the curing light beam and for generating the recording or reproducing light beam.

Abstract: According to one embodiment, an optical information recording apparatus includes a spatial light modulator, an optical mechanism, a driving module, and a controller. The spatial light modulator converts an irradiation beam emitted from a light source to plural partial information beams that carry information by causing the irradiation beam to pass through plural modulation areas. The optical mechanism collects the partial information beams onto an optical information recording medium and applies a reference beam onto the recording medium such that the reference beam and the partial information beams intersect with each other on an information recording layer. The driving module drives the recording medium or the optical mechanism. The controller performs angle multiplex recording of information on the information recording layer by controlling the driving module and causing the light source to emit the irradiation beam while switchingly supplying the modulation areas with the information.

Abstract: There is provided an optical multiplexer including: a substrate having a plurality of beam transmitting portions; and diffraction gratings diffracting beams irradiated to the beam transmitting portions at different angles, each diffraction grating being formed in the corresponding beam transmitting portion. Accordingly, it is possible to reduce an alignment error and manufacturing cost and to reduce the entire size of a recording apparatus or a reproducing apparatus.

Abstract: A holographic memory apparatus comprises first phase modulation means that adds phase information to each pixel of a signal beam to generate page data at recording time; oscillator light generation means that generates an oscillator light that is superimposed on, and interferes with, a diffracted light from a holographic recording medium at reproduction time; second phase modulation means that adds phase information to the oscillator light; and light detection means that detects an interference light generated by superimposing the oscillator light and the diffracted light from the holographic recording medium.

Abstract: Provided is an objective lens for recording a hologram that condenses an recording beam on a hologram recording medium, and the objective lens is configured so as to condense, in the case where the recording beam is incident upon the objective lens in a form of a parallel beam flux, an on-axis beam flux and an off-axis beam flux contained in the parallel flux so as to form a beam waist in the hologram recording medium, and such that a distance between an off-axis image point of the off-axis beam flux that defines a largest field angle among the off-axis beam fluxes gradually converging ahead of the beam waist and the hologram recording medium becomes minimal.

Abstract: The present invention relates to an apparatus for reading from and/or writing to holographic storage media, and more specifically to an apparatus for reading from and/or writing to holographic storage media having an improved overlap between one or more reference beams and an object beam or a reconstructed object beam. According to the invention, the apparatus has a common aperture arrangement of a reference beam and an object beam or a reconstructed object beam, wherein the focus of the reference beam is shifted relative to the focus of the object beam or the reconstructed object beam within a focal plane of the object beam or the reconstructed object beam inside or close to the holographic storage medium.

Abstract: A recording apparatus for performing information recording using formation of marks by focusing a first light with an objective lens at a given position in a recording layer included in an optical disc recording medium, includes: a rotation driving unit for rotating the optical disc recording medium; a focus servo control unit for condensing a second light which is different from the first light on a reflection film, and for controlling a position of the objective lens so that a focal position of the second light follows the reflection film; a recording position setting unit for setting an information recording position of the first light in a focus direction by changing the collimation of the first light; a surface wobbling amount estimating unit; and a surface wobbling estimation amount acquisition control unit for acquiring a surface wobbling estimation amount for each rotation angle within one revolution of the disc.

Abstract: Methods and systems for equalizing a holographic image page and for compensating nonlinearity of a holographic data storage channel are disclosed. In one embodiment, a method for equalizing a holographic image page includes receiving the holographic image page and dividing the holographic image page into a plurality of local image regions. The method further includes generating a local alignment error vector for each local image region, computing a local finite impulse response kernel for each local image region according to the corresponding local alignment error vector, and adjusting misaligned pixels of each local image region using the corresponding local finite impulse response kernel.

Abstract: Disclosed is an optical disc device that is able to increase accuracy in reproducing information from an optical disc. The optical disc device 10 calculates a focus error signal SFE2 and a sum signal SS1 while reciprocating an objective lens 21 in a focus direction until a distance between a focal point FS and a focal point FM1 becomes close to the depth d of a target position PG at the time of a pull-in operation, and when a trigger signal ST1 generated on the basis of the sum signal SS1 is at low level, starts focus control on the basis of the focus error signal SFE2. Therefore, focus control can start in a state where the focus error signal SFE2 curves in an S shape with sufficient amplitude.

Abstract: An apparatus, system, and method are disclosed to locate a group of units of digital information in a volume, optical-storage disk. The apparatus includes a first optical recording layer, a second optical recording layer, and an optical disk reading sled. The first optical recording layer stores a first group of units of digital information in a distinct region of the optical disk. The second optical recording layer stores a first locator for the first group of units of digital information in substantially the same distinct region of the optical disk. A first laser in the optical disk reading sled reads the first locator stored in the second optical recording layer, which indicates the contents of the units of digital information stored in the first optical recording layer being read by a second laser, also in the optical disk reading sled.

Abstract: An optical recording apparatus comprises: a focusing section that focuses to a transmission type recording medium a recording light beam including a signal light beam and a reference light beam which are radiated from a same direction with a common optical axis; and a focused-position moving section that moves with respect to a direction of the optical axis a focused position where the recording light beam is focused to the transmission type recording medium by the focusing section, wherein an interference fringe formed by the recording light beam is recorded in the transmission type recording medium at each position which is moved by the focused-position moving section.

Abstract: An optical pickup device is provided with a spectral element which imparts diffraction in such a manner that four light fluxes of the first laser light are separated from each other, when a light flux of the first laser light and a light flux of the second laser light reflected on a recording medium having laminated recording layers and servo layers are divided into four by a first straight line in parallel to a converging direction by an astigmatism element, and a second straight line perpendicular to the first straight line, and that the four light fluxes of the first laser light propagate on an outer side than the light flux of the second laser light; and a photodetector including a first sensor group which receives the first laser light, and a second sensor group which receives the second laser light.

Abstract: A holographic read only memory card which can be coupled to and read by a card reader to which electronic read only memory cards can also be coupled to and read by the card reader is disclosed. The holographic read only memory card comprises: a housing having a compartment for receiving a holographic storage medium; a holographic storage medium having stored thereon holographic data; and optionally a an electronics panel member having an electronic memory component which can be read by the card reader when the holographic read only memory card is coupled to the electronic card reader. The housing comprises one or more card locating members to thereby repeatedly position the holographic read only memory card each time the holographic read only memory card is coupled to the electronic card reader so that the holographic data can be read.

Abstract: Techniques are provided for controlling the reading of optical data from a master disk in a holographic replication system. Imperfections in the master disk or movement of the disk during a recording process may cause source beams to deviate from target data tracks. In some embodiments, a detector system is used to determine the focus and alignment of the source beams on the master disk, as well as the tilt and rotation of the disk with respect to the holographic replication system. The detector system may detect deviations in the intensity distribution of the reflections of the source beams and generate an error signal corresponding to focusing, tracking, tilt, and/or rotational errors. Servo-mechanical devices may actuate optical components to compensate for such errors.

Abstract: A system for processing information is provided. The system includes multiple micro-holograms contained in multiple volumes arranged along multiple tracks in one or more storage mediums. Each of the micro-hologram includes a data. The system also includes one or more pick-up head devices with optical lenses for directing laser beams on the multiple tracks. Further, the system includes a subsystem for arranging the one or more pick-up head devices for recording and retrieving of the data from the one or more storage mediums.

Abstract: A hologram recording apparatus (300) is provided with: a recording device (100) for recording record information into a hologram recording medium (1); a measuring device (325) for measuring a time elapsed from when the recording of the record information is stopped to when the recording of the record information is restarted; a first controlling device (354) for controlling the recording device to multiplex-record the record information, if the measured elapsed time is shorter than a time length in which the record information can be multiplex-recorded; and a second controlling device (354) for controlling the recording device not to multiplex-record the record information, if the measured elapsed time is longer than the time length in which the record information can be multiplex-recorded.

Abstract: An optical pickup head is provided, which includes a silicon substrate, in which an aperture and an objective lens are disposed on the silicon substrate; and a laser diode (LD), a 135-degree tilted reflector, and a 135-degree tilted holographic reflector are disposed on the silicon substrate. The two 135-degree tilted reflectors and a holographic optical element (HOE) are fabricated on a slant face structure of an optical platform using a semiconductor process, so all the elements are disposed at a straight zone, and then in combination with bonding of the LD and an optical sensor element, an miniaturization objective is achieved and an optical path is shortened.

Abstract: An optical disc apparatus can highly accurately record a hologram representing information on or reproduce such a hologram from an optical disc. When recording information on an optical disc 100, the optical disc apparatus controls the position of an objective lens OL1 according to the outcome of detection of a red reflected light beam Lr2 so as to make the focus Fr thereof follow a target track and it also makes the focus Fb1 of a blue light beam Lb1 agree with a target mark position by the objective lens OL1 and also the focus Fb2 agree with the target mark position by controlling the position of another objective lens OL2 according to the outcome of detection of the blue light beam Lb1 by way of the objective lenses OL1 and OL2 so as to make the focus Fb1 of the blue light beam Lb1 and the focus Fb2 of the blue light beam Lb2 agree with the target mark position and the blue light beam Lb1 and the blue light beam Lb2 interfere with each other.

Abstract: The present techniques provide techniques for outputting counter-propagating parallel light waves to pre-record a holographic data disk. The parallel light waves are transmitted through a holographic system via a fiber optic bundle including a plurality of polarization-maintaining (PM) optical fibers. Each of the PM optical fibers in the fiber optic bundle may have one or more of a different wavelength, a different coherence length, and a different polarization orientation to reduce crosstalk in the disk. Furthermore, the fiber optic bundle array is rotated to produce interference spots indicative of micro-holograms according to the data track pitch of the holographic disk over which the fiber optic bundle is outputting the light waves.

Abstract: The present techniques provide methods and systems for enhancing a data signal in reading optical discs, such as holographic data discs. The techniques involve adjusting the position of a detector, or multi-pixel detector, such that the reflection corresponding to a micro-hologram or micro-reflector is enhanced. For example, the detector position may be adjusted to a position where the surface reflection and the micro-hologram reflection constructively interfere, resulting in an amplified micro-hologram reflection signal. Other parameters such as disc reflectivity and detector pinhole size may be adjusted to increase signal enhancement. Furthermore, the detector position may be adjusted to a position where the phases of the surface reflection and the micro-hologram reflection result in a weaker cross term.

Abstract: An optical unit is provided with a light source; a light dividing means for dividing light emerging from the light source into a first light and a second light; a light converging means for converging the first and second lights at the same position in the recording layer in the manner that they face each other; a polarization state switching means for switching the polarization states of the first and second lights at the convergence point in the recording layer; and a light irradiation state switching means for switching between the state in which the optical cording medium is irradiated with both the first light and the second light and the state in which the optical recording medium is irradiated with only one of the first and second lights.

Abstract: Provided is a holographic recording/reproducing apparatus including an aperture device having aperture of variable size. The holographic recording/reproducing apparatus includes a light source, an optical system to divide light emitted from the light source into a recording reference beam and a recording signal beam, and direct the recording reference beam and the recording signal beam to a same location of a holographic recording medium, a spatial light modulator (SLM) to modulate the recording signal beam into a two-dimensional signal pattern, a two-dimensional photodetector to detect a reproducing signal beam that is refracted via the holographic recording medium, and the aperture to limit a size of a spot of the reproducing signal beam, wherein the size of the aperture is variable.

Abstract: The present techniques provide methods and systems for more reliable reading of optical data disks. In embodiments, a multi-pixel detector that is segmented into multiple areas, or detector segments, may be used to detect a pattern in the light reflected from an optical data disk. The pattern may include light scattered from a single bit that may be under a center detector, as well as light scattered from proximate bits. The detector system may then combine the quantized values from each of the detector segments mathematically to determine the presence or absence of a bit or bits of data. The mathematical combination may also use data that is known about the status of adjacent data bits (such as previously read bits, or bit patterns which are allowed or not allowed by specific data encoding schemes) to improve the accuracy of the bit prediction.

Abstract: Exemplary embodiments are provided for recording and reading optical information using holography in which a first recording operation is performed in a first recording region in an overlapping manner by allowing a reference beam and a signal beam with data loaded to interfere with each other in the first recording region, the reference beam being angularly multiplexed at predetermined intervals. And a second recording operation is performed in a second recording region located adjacent to the first recording region or overlapped with the first recording region by allowing the reference beam and the signal beam to interfere with each other in the second recording region, the reference beam being angularly multiplexed between the predetermined intervals.

Abstract: The present invention relates to a holographic recording medium adapted to store additional information for the recorded holograms, and to a holographic pickup for a holographic storage system for use with the holographic recording medium. According to the invention, the holographic recording medium has a holographic layer for storing holograms and a servo layer for positioning a light beam for reading and/or recording of a hologram relative to the holographic recording medium, wherein the servo layer is recordable or rewritable. A holographic pickup for use with such a holographic recording medium includes a light source for recording additional data in the servo layer of the holographic recording medium.

Abstract: An initialization apparatus that has a simplified configuration and that forms an initial hologram in an information recording medium is provided. An initialization apparatus (10) rotates an optical disk (100) and emits blue light beams (Lb1) and (Lb2) to either side of the optical disk (100) while causing a red light beam (Lr1) to follow a track formed in a reference layer (102). Thus, the initialization apparatus (10) can perform an initialization process in which a linear initial hologram IH is formed in a recording layer (101) in a spiral pattern that corresponds to the track formed in a reference layer (102). Accordingly, the initialization apparatus (10) can form a planar initial hologram layer (YH) with significantly reduced optical energy or thermal energy emitted to the optical disk (100) at one time.

Abstract: An optical information recording/reproducing apparatus and an optical information recording/reproducing method that record information using holography, wherein the optical information recording/reproducing apparatus includes a signal generation unit that generates two-dimensional data by a two-dimensional encoding method in which a lower-limit value of a number of continuous ON/OFF pixels in an array in one direction of pixels in a two-dimensional spatial light modulator is K(K?2, K: natural number); and a pickup that records the two-dimensional data, generated by the signal generation unit, on a hologram disc.

Abstract: Methods and systems are provided for recording micro-holograms in a holographic disk. Disk tilting or disk imperfections may cause counter-propagating recording and reference beams to deviate from the target data position in the disk. In some embodiments, a tracking beam is directed to a tracking position in the disk, and deviation of the tracking beam from the tracking position may indicate tracking and/or focusing errors of the recording and/or reference beams. A detector may generate an error signal in response to such errors. A first servo-mechanical system may actuate a first optical head (e.g., transmitting the reference and tracking beams) to compensate for such errors, and a second servo-mechanical system may actuate a second optical head (e.g., transmitting the recording beam) to follow the actuation of the first servo system, such that an interference of the reference beam and the recording beam may be maintained in the target data position.

Abstract: Techniques are provided for controlling the reading of micro-holograms from a holographic disk based on a target data layer to be read in the disk. Reading a target data layer which is relatively deeper in the disk (e.g., farther from an optical head emitting a reading beam) may involve using a higher power reading beam to compensate for power attenuation of the returned reading beam. For example, a power adjustment module may be used to dynamically adjust a reading laser emitting the reading beam, based on the dynamically changing target data layer. By compensating for power attenuation in deeper target data layers, the variance of power in the returned reading beams may be decreased, possibly improving the bit error rate in micro-hologram reading techniques.

Abstract: Techniques are provided for increasing storage capacity in a holographic storage system. While typical holographic storage systems involve binary storage for each data position in a holographic disk, present techniques involve storing data such that more than two data levels may be recorded in each data position. In some embodiments, a recording beam directed to the disk may be adjusted to different power levels depending on the data level to be recorded. Furthermore, the recording time at a data position may be adjusted to increase the energy directed to the data position by increasing the amount of time the recording beam is impinged on the data position. Embodiments are suitable for different types of holographic storage, including dye-based medium.

Abstract: An optical pickup of a holographic data recording/reproducing apparatus that emits light to a reflective holographic data storage medium in which a substrate, a reflection layer, a recording layer, and a cover layer are sequentially stacked, and receives the emitted light, the optical pickup including: a first light source unit to emit, during a recording operation, a signal beam having a first polarization and a reference beam having a second polarization perpendicular to the first polarization along the same optical path; and a main lens unit having a refractivity that varies according to a polarization of a passing light, so as to cause the signal beam to be reflected from the reflection layer then focused on a focal point, and to cause the reference beam to pass through the cover layer then be directly focused on the focal point.

Abstract: In reproduction of a two-dimensional page data from an optical information recording medium utilizing holography, a reproduced two-dimensional page data is divided into a plurality of areas each of which has a predetermined size, the divided two-dimensional areas are individually subjected to adaptive equalizing, and then are coupled to restore the condition of the original two-dimensional page data.

Abstract: There is provided an optical information recording/reproducing apparatus having an optical disc drive unit for driving an optical disc mounted, a hologram disc drive unit for driving a hologram disc mounted, a disc discrimination device for discriminating which of an optical disc and a hologram disc was mounted, a selection device of the disc drive unit for selecting an optical disc drive unit, when discriminated to be an optical disc, by the disc discrimination device, while selecting a hologram disc drive unit, when discriminated to be a hologram disc, by the disc discrimination device, and a drive device of the disc drive unit for driving the disc drive unit selected by the selection device of the disc drive unit.

Abstract: An optical data storage medium is provided. The optical data storage medium includes a polymer matrix; a reactant capable of undergoing a change upon triplet excitation, thereby causing a refractive index change; and a non-linear sensitizer capable of absorbing actinic radiation to cause upper triplet energy transfer to said reactant. The refractive index change capacity of the medium is at least about 0.005. The non-linear sensitizer comprises a triarylmethane dye.

Abstract: The present invention provides a holographic storage apparatus comprising a polarizing beam splitter configured to split an incoming beam into an object beam and a reference beam; a first spatial light modulator configured to modulate the object beam with an array of data; a second spatial light modulator configured to phase modulate the reference beam with an orthogonal phase function; a holographic medium configured to record an interference pattern between the modulated object beam and the modulated reference beam; a first image sensor configured to read an image of the modulated object beam; and a second image sensor configured to read an image of the modulated reference beam.