Abstract: There is herein defined optics (e.g. an array of optics) forming an optical beam to either produce a collimated or diverging/converging beam emerging from a virtual source point to illuminate a hologram. There is also described an optical beam illuminating a reflection hologram from the front and a further configuration where an optical beam combined with a holographic optical element (HOE) minor enables rear illumination of a reflection hologram.

Abstract: There is herein defined optics (e.g. an array of optics) forming an optical beam to either produce a collimated or diverging/converging beam emerging from a virtual source point to illuminate a hologram. There is also described an optical beam illuminating a reflection hologram from the front and a further configuration where an optical beam combined with a holographic optical element (HOE) minor enables rear illumination of a reflection hologram.

Abstract: An apparatus and method for displaying holograms. A compact and self-contained lighting system for a display hologram, which can produce high quality images and which is substantially insensitive to stray light.

Abstract: An apparatus and method for displaying holograms. A compact and self-contained lighting system for a display hologram, which can produce high quality images and which is substantially insensitive to stray light.

Abstract: There is herein described apparatus and methods for displaying holograms. At least one aspect of the invention is to provide a compact and self-contained lighting system for a display hologram, which can produce high quality images and which is substantially insensitive to stray light.

Abstract: An optical data storage disk includes a central substrate and on each side of the substrate a pair of metal/alloy recording layers separated by a transparent layer.

Abstract: There is herein described apparatus and methods for displaying holograms. At least one aspect of the invention is to provide a compact and self-contained lighting system for a display hologram, which can produce high quality images and which is substantially insensitive to stray light.

Abstract: The present invention relates to: stabilizing a holographic disk medium against vibrations by engaging at least one of surface of a disk medium when coupled to a disk medium coupler and during recording or reading holograms to or from the disk; stabilizing the disk medium proximate the outer peripheral portion thereof, coupling and uncoupling the disk medium to and from the disk medium coupler and causing the stabilizing means to engage the disk medium when coupled to the disk medium coupler; imparting an axial offset proximate the peripheral portion to deflect a record and/or read portion of the disk medium towards a normal record and/or read plane when coupled to the disk medium coupler, and optionally stabilizing the disk medium against vibrations; and stabilizing the disk medium against vibrations when rotatably mounted on or within a data storage cartridge.

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 (radial tilt direction), 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. A reference tilt hologram for specifying a reference incident angle of the reference beam in a radial tilt direction is recorded in advance on a holographic memory medium. During recording and reproducing operations, the reference beam is emitted to a recording position of the reference tilt hologram and the reference incident angle (reference angle Sr) of the reference beam in the radial tilt direction is detected based on a received light state. A tilt actuator (19) 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.

Abstract: An optical head of a type useable in a optical disk reader/writer is provided. The optical head has a low profile, e.g., in a vertical direction parallel to the disk spin axis, such as less than about 5 mm preferably less than about 3 mm. Substantially all components of the optical system, including a laser source, objective lens, intervening optics and photo detector are provided in the optical head and mounted in a fixed position with respect to one another. Substantially all optical components of the optical head are moved as a unit, e.g., during tracking and/or focusing. Preferably, the optical head is fabricated using wafer scale and/or stacking technologies, e.g., stacking substantially planar components to achieve the final optical head configuration.

Abstract: To properly reproduce information from a holographic memory even when a tilt error occurs in a direction vertical to a surface including optical axes of data light and reference light. During reproduction, a holographic memory (10) is fed stepwise from an initial access position with respect to a reproduction target block within a fixed back and forth range in a disk circumferential direction. In each stepwise-fed position, an SNR of a reproduction signal is calculated by an SNR calculation circuit (19) to detect the quality of the reproduction signal. A disk circumferential direction position in which an SNR becomes best is set in a circumferential direction position with respect to the reproduction target block.

Abstract: The present invention relates to a system comprising a holographic data storage drive that records holographic digital data in a holographic recording medium, and which comprises: a data beam path having a first optical path length; and a reference beam path having a second optical path length; wherein one of the data beam and reference beams paths comprise an optical delay line so that the difference between the first and second optical path lengths is less than the laser coherence length. The present invention further relates to a method for operating a laser in the holographic data storage drive in a multi-mode state during the recording of holographic digital data the holographic medium without adverse effects on the strength of the interference patterns formed.

Abstract: A user-removable optical data storage system is provided. A rotatable first-surface medium is enveloped in a cartridge. The cartridge provides relatively large data capacity such as about 0.25 Gbytes or more despite a relatively small size such as about 35 mm×35 mm×3 mm. Preferably the cartridge substantially seals the data surfaces of the medium when the cartridge is withdrawn from a drive and at least a portion of one surface is automatically exposed to the objective of an optics arm when said cartridge is inserted in the drive. Tracking involves rotating an optic arm about an axis parallel to the disk rotation axis. Focus can involve pivoting the arm about an axis parallel to the disk surface.

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: The present invention relates to embodiments of a process for subjecting a holographic storage medium to illuminative treatment to: (1) enhance or optimize recording of holographic data; (2) enhance or optimize reading of recorded holographic data; and/or (3) erase recorded holographic data. The present invention also relates to embodiments of a system comprising: (a) an illuminative treatment beam; (b) means for reducing the coherence of the beam and (c) means for transmitting the reduced coherence beam to cause illuminative treatment of: (1) an unrecorded portion of a holographic storage medium to provide pre-cured portions having increased ability to stably record holographic data; (2) a recorded portion of a holographic storage medium to provide a post-cured portion having reduced residual sensitivity; and/or (3) a recorded portion of a holographic storage medium having holographic data to provide an erased portion wherein at least some of the recorded holographic data is erased.

Abstract: The present invention relates to embodiments of a process for subjecting a holographic storage medium to illuminative treatment to: (1) enhance or optimize recording of holographic data; (2) enhance or optimize reading of recorded holographic data; and/or (3) erase recorded holographic data. The present invention also relates to embodiments of a system comprising: (a) an illuminative treatment beam; (b) means for reducing the coherence of the beam and (c) means for transmitting the reduced coherence beam to cause illuminative treatment of: (1) an unrecorded portion of a holographic storage medium to provide pre-cured portions having increased ability to stably record holographic data; (2) a recorded portion of a holographic storage medium to provide a post-cured portion having reduced residual sensitivity; and/or (3) a recorded portion of a holographic storage medium having holographic data to provide an erased portion wherein at least some of the recorded holographic data is erased.

Abstract: Systems and methods are provided or use with a light source which generates a light beam. These systems may include a detector which detects light beam information regarding a light beam exiting an etalon. The system then uses the detected information to determine whether multiple modes are present in the light beam so that the light source may be adjusted to return the light source to single mode operation.

Abstract: Systems and methods are provided or use with a light source which generates a light beam. These systems may include a detector which detects light beam information and which determines whether multiple modes are present in the light beam so that the light source may be adjusted. These systems may further include a beam splitting device, such as an optical wedge, to provide two sample beams that intersect to provide a fringe pattern. The detector may then detect this fringe pattern and compute a visibility value that may be used to determine whether multiple modes are present.

Abstract: The present invention relates to embodiments of a process for subjecting a holographic storage medium to illuminative treatment to: (1) enhance or optimize recording of holographic data; (2) enhance or optimize reading of recorded holographic data; and/or (3) erase recorded holographic data. The present invention also relates to embodiments of a system comprising: (a) an illuminative treatment beam; (b) means for reducing the coherence of the beam and (c) means for transmitting the reduced coherence beam to cause illuminative treatment of: (1) an unrecorded portion of a holographic storage medium to provide pre-cured portions having increased ability to stably record holographic data; (2) a recorded portion of a holographic storage medium to provide a post-cured portion having reduced residual sensitivity; and/or (3) a recorded portion of a holographic storage medium having holographic data to provide an erased portion wherein at least some of the recorded holographic data is erased.

Abstract: An optical head of a type useable in a optical disk reader/writer is provided. One of the optical elements is provided in a fashion that one or more optical parameters or characteristics of the system are invariant, regardless of whether the one optical element is used, or not. In one embodiment the optical element is a beamshaper. In order to provide the desired invariant property, the surfaces of the optical element are preferably formed with high accuracy. One manner of economically achieving high accuracy is to measure errors or imperfections in a first formed, preferably etched, surface and adjust the shape or position of a second aligned etched surface so as to at least partially compensate for the errors or imperfections.