Abstract: A method is provided for manufacturing a holographic medium by recording holograms in transmission geometry, and applying a reflective layer to one side of the holographic recording material after recording is completed (alternatively, for example, the playback system may contain a reflective surface or mirror). For readout, the reference beam is incident to the media from a side opposite the reflective layer. This beam propagates through the media to the reflective layer on the opposite side, and is reflected back through the media for readout of the transmission hologram. The diffracted hologram signal also exits the media on the side without the reflective layer, where it can be recovered by a detector on the same side as the laser source. Alternatively, the readout reference beam is positioned so that the incident beam reads out the hologram, and both the reference beam and diffracted hologram are reflected back through the media.

Abstract: In one aspect of the present invention, a device for sensing an absolute position of an encoded object, comprising: a position tracking module comprising: a track illumination module configured to illuminate the encoded object with one more light beams, and to detect one or more light beams resulting from said illumination of said encoded object; and an absolute position determinator configured to determine the absolute position of the encoded object based on said one or more light beams resulting from said illumination of said encoded object.

Abstract: Structures, subassemblies, devices, systems, and subsystems selected from: (1) a unitary holographic drive head assembly mounting structure; (2) an assembly including a unitary holographic drive head assembly mounting structure and a plurality of holographic drive head components and/or subassemblies; (3) a subassembly including a spatial light modulator, detector array, and a beam splitter; (4) a device including a spatial light modulator and a physical aperture positioned over or an imaged aperture projected onto the photoactive area of the spatial light modulator; (5) a system for optically aligning or pointing a laser in a holographic drive head assembly; (6) a light source subassembly including a laser, a fiber coupling lens; and an optical fiber having a fiber connector ready output end; and (7) a light source subsystem including a laser source, beam conditioning optics, fiber coupling optics for receiving the conditioned light beam, and a fiber optic connector for receiving the conditioned light beam f

Abstract: Systems and methods for recovering data in a holographic memory system. The systems and methods use homodyne detection to introduce a local oscillator beam into a reconstructed data beam of the recovered hologram. An image of the combined beam comprising the reconstructed data beam and local oscillator beam may be processed to obtain contrast level information for the pixels of the detected image. This contrast level information may then be used to obtain an increased contrast image of the recovered hologram, which may increase the SNR of the recovered data.

Abstract: Described are holographic storage mediums and method of making holographic storage mediums. The holographic storage mediums may have write components that bind to the matrix to form a pattern in the media. The holographic storage mediums may also be rewriteable.

Abstract: The present invention provides one or more books of holograms recorded in a recording medium, wherein two or more short stacks of the one or more books have locations that differ from each other by a movement difference. The present invention also provides methods and devices for recording and reading holograms from the one or more books of holograms.

Abstract: To provide an optical recording apparatus capable of effectively suppressing useless fixation to an information-unrecorded area during a fixing process with a simple structure, and an optical head. Upon recording information, a movable lens of an expander lens 104 is positioned in an information recording position. In an information fixing process, the movable lens of the expander lens 104 is positioned in a fixing-process position. In this case, a range of irradiation to the recording medium with the data light becomes somewhat wider than that in the information recording process. Accordingly, it is possible to fix the information to an area irradiated with the data light in the information recording process without fail. In addition, the irradiation range is only somewhat wider than that in the information fixing process, making it possible to minimize the region uselessly subjected to the fixing process.

Abstract: The present invention provides a scanner comprising: a reflector component; means supporting the reflector component for pivoting with respect to the MCR to provide a scan which is stationary with respect to the OCR; means for enabling the support means to provide controlled pivoting of the reflector component; a magnet component which causes pivoting of the reflector component when actuated; and means for actuating the magnet component to thereby cause pivoting of the reflector component. Also provided is a scanner comprising a reflective prism for providing a circularized scanning beam, a prism carrier and magnet suspension assembly, and flexure means connected to the assembly to enable the prism to controllably pivot: (1) with respect to the MCR axis to provide a scan which is stationary with respect to the OCR; and (2) with respect to a pitch axis orthogonal to the MCR to provide an orthogonal scan.

Abstract: Methods and systems are provided for obtaining a phase conjugate reconstruction beam for use in retrieving holographic information from a holographic storage medium. These methods and systems include generating a coherent light beam that is a reproduction of the reference beam used in storing the holographic information in the storage medium. This coherent light beam is then directed through the holographic storage medium at the same angle and location of the reference beam during recording of the hologram. The directed coherent beam is then reflected back through the storage medium so that the reflected coherent light beam provides a phase conjugate of the reference beam and passes through the storage medium at the same angle and location that the reference beam passed through the storage medium during recordation of the hologram.

Abstract: A new type of FT lens is provided that improves phase conjugation in holographic data systems. This type of FT lens has a uniquely large isoplanatic patch. This enables relaxed assembly tolerances, asymmetric reader/writer architectures, and compensation for tilted plate aberrations in the media.

Abstract: Described are holographic storage mediums and method of making holographic storage mediums. The holographic storage mediums may have write components that bind to the matrix to form a pattern in the media. The holographic storage mediums may also be rewriteable.

Abstract: A laser system comprising a laser assembly for generating a light beam, and collimation assembly movable axially with respect to the laser assembly and being positioned in the optical path of the light beam. The collimation assembly comprises a collimation lens group comprising a first lens component positioned within a first lens mounting cell, a second lens component positioned within a second lens mounting cell and provided with a central portion for receiving and cooperating with the first cell to thereby adjust the axial spacing between the first and second lens components, means for radially adjusting the position of the second cell with respect to the first cell to thereby radially adjust the optical axis of the second lens component with respect to the optical axis of the first lens component, and means formed in the central and flange portions of the second cell for creating flexure therein.

Abstract: Disclosed is a holographic data storage device including holographic media for containing data, writing data to and reading data from. The storage device also includes at least one supplemental memory for containing at least a portion of a directory of the data contained in the holographic media. By locating directory information for the holographic media in a supplemental memory, areas of the holographic media that have not yet been written to can be determined prior to accessing the holographic media. In this way, activating photo-sensitive agents in unwritten areas of the holographic media can be avoided unless these areas are being written to.

Abstract: Even when a tilt error is caused in a holographic memory in a direction perpendicular to a surface including optical axes of a signal beam and a reference beam, the signal beam and the reference beam are allowed to enter the holographic memory at adequate angles relative thereto at all times by suppression of the tilt error. During recording and reproducing operations, the reference incident angle of the reference beam in the radial tilt direction is detected based on a received light state. A tilt actuator for displacing the holographic memory medium in the radial tilt direction is driven to adjust an incident angle of the reference beam in the radial tilt direction to the reference angle Sr. Then, the signal beam and the reference beam are emitted to the holographic memory medium to execute the recording and reproducing operations.

Abstract: Aspects of the present invention are generally directed to a holographic system. Generally, aspects of the present invention are directed to allocating power of a light beam generated by a coherent light source among the various discrete light beams used in a holographic system. Specifically, a variable optical divider is incorporated into an optical steering subsystem of the holographic memory system to redirect the coherent light beam into one or more discrete light beams, and to dynamically allocate power of the coherent light beam among the discrete light beams.

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: A data storage cartridge is described. The cartridge may include a housing having a top, a bottom, a front side, a back side, a first lateral side, and a second lateral side, said housing having a first media access aperture on the top of the housing; and a data storage medium contained within the housing, the data storage medium including a disk with a top and a bottom; wherein the front side of the housing contains a first segment of reduced thickness adjacent to the first media access aperture.

Abstract: The present invention relates to embodiments of: (1) a unitary holographic drive head assembly mounting structure; (2) an assembly comprising a unitary holographic drive head assembly mounting structure and a plurality of holographic drive head components and/or subassemblies; (3) a subassembly comprising a spatial light modulator, detector array, and a beam splitter; (4) a device comprising a spatial light modulator and a physical aperture positioned over or an imaged aperture projected onto the photoactive area of the spatial light modulator; (5) a system for optically aligning or pointing a laser in a holographic drive head assembly; (6) a light source subassembly comprising a laser, a fiber coupling lens; and an optical fiber having a fiber connector ready output end; and (7) a light source subsystem comprising a laser source, beam conditioning optics, fiber coupling optics for receiving the conditioned light beam, and a fiber optic connector for receiving the conditioned light beam from the fiber couplin

Abstract: The present invention provides a scanner comprising: a reflector component; means supporting the reflector component for pivoting with respect to the MCR to provide a scan which is stationary with respect to the OCR; means for enabling the support means to provide controlled pivoting of the reflector component; a magnet component which causes pivoting of the reflector component when actuated; and means for actuating the magnet component to thereby cause pivoting of the reflector component. Also provided is a scanner comprising a reflective prism for providing a circularized scanning beam, a prism carrier and magnet suspension assembly, and flexure means connected to the assembly to enable the prism to controllably pivot: (1) with respect to the MCR axis to provide a scan which is stationary with respect to the OCR; and (2) with respect to a pitch axis orthogonal to the MCR to provide an orthogonal scan.

Abstract: 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.