摘要:
An optical disc for micro-holographic data storage, including: optically-enabled material configured to store holographic data; guide grooves; a first coating disposed on the guide grooves and configured to reflect a tracking beam and to transmit a read or record beam; and a second coating disposed to cover the guide grooves and disposed on the first coating.
摘要:
A system and method for controlling tracking in a holographic data storage system, including: impinging a beam on a holographic data disc, wherein the beam is reflected from a micro-hologram disposed within the holographic data disc; detecting the reflected beam from the holographic data disc by a multi-element detector; and analyzing a pattern detected by multi-element detector to generate a tracking error signal.
摘要:
An optical disc for micro-holographic data storage, including: optically-enabled material configured to store holographic data; guide grooves; a first coating disposed on the guide grooves and configured to reflect a tracking beam and to transmit a read or record beam; and a second coating disposed to cover the guide grooves and disposed on the first coating.
摘要:
A system and method for controlling tracking in a holographic data storage system, including: impinging a beam on a holographic data disc, wherein the beam is reflected from a micro-hologram disposed within the holographic data disc; detecting the reflected beam from the holographic data disc by a multi-element detector; and analyzing a pattern detected by multi-element detector to generate a tracking error signal.
摘要:
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.
摘要:
A method for calculation of recording depth in a holographic disk is disclosed. The method includes applying a first external voltage to one or more actuators coupled to an objective lens to focus a tracking beam of radiation having a first wavelength on a reference layer of the disk, wherein the reference layer comprises at least one of a partially dichroic coating or a partially metallized coating. The method also includes applying a second external voltage to the one or more actuators coupled to the objective lens to focus a recording beam of radiation on the reference layer of the disk, wherein the recording beam comprises a second wavelength different from the first wavelength of the tracking beam. The method further includes computing a difference between the first external voltage and the second external voltage. The method also includes calculating a lens-shift distance based upon the difference using a voltage-distance calibration curve, wherein the lens-shift distance refers to a shift in distance of the objective lens in order to focus the tracking beam of radiation and the recording beam of radiation on the reference layer respectively. The method also calculates the recording depth based upon the lens-shift distance.
摘要:
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.
摘要:
The present techniques provide methods and systems for recording micro-holograms on a holographic disk using a plurality of counter-propagating light beams in parallel. The parallel counter-propagating light beams overlap to form interference patterns on a data layer and over multiple data tracks in the holographic disk. Rotating the disk enables the parallel recording of micro-holograms over multiple data tracks, thus reducing recording time. Further, the illumination pattern may include illuminated spots and non-illuminated regions, such that each illumination spot may cover a relatively small fraction of the data layer plane, possibly controlling the depth spread of the recorded micro-hologram. In some embodiments, data in the parallel signal beams may be retrieved from a master holographic disk or may be modulated into the parallel signal beams.
摘要:
The present techniques provide methods and systems for controlling the recording of micro-holograms using multiple counter-propagating light beams over multiple data tracks of a holographic disk. Imperfections in a holographic disk or movement of the disk during a recording process may cause signal beams to deviate from target data tracks. In some embodiments, a tracking beam is directed to a reference layer in the disk. Deviation of the reference beam from a target groove in the reference layer may be indicative of tracking errors. A detector may detect reflections of the tracking beam and generate an error signal in response to detected tracking errors. Servo-mechanical devices may actuate (e.g., radially, tangentially, or axially translate, rotate, and/or tilt) one or more optical components through which the counter-propagating light beams are emitted to compensate for tracking errors.
摘要:
A method for processing information is provided. The method includes directing a laser beam to a first track of a first layer of a holographic storage medium. The method also includes recording a base voltage based on a look-up table. The method includes directing the laser beam to a target track in the first layer, based on position information in tracks. Further, the method includes recording an offset voltage for the target track into the look-up table. Still further, the method includes directing the laser beam to a target layer based on position information in vertical wobbles. The method also includes recording an offset voltage for the target layer into the look-up table. Finally, the method includes determining a final voltage based on the look-up table and applying the final voltage to an actuator for moving the laser beam to a final target position in the holographic storage medium for recording and retrieval of information.