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: 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 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.

Abstract: A method for servoing when reading out a recorded holographic disk or recording in a preformatted holographic disk is disclosed. The method includes detecting a primary signal of a reflected primary beam from a target data track of a target data layer of the holographic disk, wherein the primary beam of radiation has a first wavelength. The method also includes comparing a power measurement of the primary signal with a threshold value of power. The method also includes detecting a tracking signal of a reflected tracking beam from a reference layer of the holographic disk in an event that the power measurement of the primary signal is below the threshold value of power, wherein the tracking beam of radiation has a second wavelength. The method also includes generating a servo error signal based upon the primary signal or the tracking signal.

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 data storage device including: a plastic substrate having a plurality of volumes arranged in tracks along a plurality of vertically stacked, laterally extending layers therein; and, a plurality of micro-holograms each contained in a corresponding one of the volumes; herein, the presence or absence of a micro-hologram in each of the volumes is indicative of a corresponding portion of data stored.

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 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.

Abstract: 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.

Abstract: 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.

Abstract: The present techniques provide methods and systems for alignment of a read head with data tracks on an optical data disk. 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 detector system may then combine the quantized values from each of the detector segments mathematically to determine the alignment of the read head with a target data track. If the read head drifts to one side or the other, detectors to the side of a center detector may start to pick up energy from the adjacent tracks. If this energy is continuously summed for the detectors on each side, the read head may be centered by balancing the sums from the detectors on each side.

Abstract: Provided are methods and systems of encoding and decoding techniques in an optical storage system having a multi-head detector. In one embodiment, source data may be encoded using error correction coding (e.g., turbo coding) techniques, and the encoded data may be interleaved and distributed to more than one detector head of the multi-head detector. Data recorded in an optical disc may be retrieved by the multi-head detector, and a read data from more than one detector head may be concurrently decoded to retrieve estimates of the original information in the source data. Further, more than one encoder/decoder may be used, and each encoder/decoder may encode or decode data from multiple data heads. Some embodiments also include replicating multiple discs.

Abstract: The present techniques provide systems and methods for modulation coding of data on optical disks, such as holographic data disks, and techniques for reading that data back from the disks. The techniques involve parsing a bit stream into a sequence of individual bit-patterns, and then using the individual bit patterns to select a symbol, or matrix, from a lookup table of previously selected matrices. The symbols are selected according to predetermined criteria that may help make the disk more resistant to interferences and errors, such as surface scratches, and the like. For example, criteria that may be used to select the symbols are the number of reflective and non-reflective regions within each matrix, and the number of sequential reflective regions, among others. The symbols may be written to the disk in a two-dimensional fashion, e.g., across adjacent tracks, or in a three-dimensional fashion, e.g., across adjacent data layers.

Abstract: A data storage device including: a plastic substrate having a plurality of data volumes arranged along tracks in a plurality of stacked layers; a plurality of micro-holograms each contained in a corresponding one of the data volumes; a plurality of complementary volumes, each corresponding to and being substantially aligned with one of the data volumes; a plurality of micro-holograms each contained in a corresponding one of the complementary volumes; wherein, the presence or absence of a micro-hologram in each of the data volumes is indicative of a corresponding portion of data stored; and, the ones of the complementary volumes corresponding to the ones of the data volumes containing a micro-hologram do not contain a micro-hologram; and the ones of the complementary volumes corresponding to the ones of the data volumes not containing a micro-hologram contain a micro-hologram.

Abstract: Provided are methods and systems of encoding and decoding techniques in an optical storage system having a multi-head detector. In one embodiment, source data may be encoded using error correction coding (e.g., turbo coding) techniques, and the encoded data may be interleaved and distributed to more than one detector head of the multi-head detector. Data recorded in an optical disc may be retrieved by the multi-head detector, and a read data from more than one detector head may be concurrently decoded to retrieve estimates of the original information in the source data. Further, more than one encoder/decoder may be used, and each encoder/decoder may encode or decode data from multiple data heads. Some embodiments also include replicating multiple discs.

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 device including a layer comprising a light emissive area and a light non-emissive area. A light-extracting feature is disposed over the light non-emissive area. The light-extracting features can include surface aberrations and reflective index matching elements. A method of forming the device is also provided.

Abstract: A new method that integrates electrochemical oxidation and flocculation processes for removing ammonia nitrogen in coking wastewater is disclosed in this invention. It comprises steps as follow: first, adjusting the PH of coking wastewater and adding Fe2+ into the wastewater; then leading the wastewater containing Fe2+ through such 5 areas as pulsed high-voltage discharge oxidation area, pulsed high-frequency DC electrolytic oxidation area, microbubble oxidation area, flocculation area and precipitation area in succession. High-voltage pulse and high-frequency pulse are two different mechanisms for achieving strong oxidation. With help of both solid and liquid catalysts, these two oxidations can work synergistically. The recalcitrant organic chemicals are effectively destroyed and satisfactorily removed out of wastewater. The high-concentration coking waster pretreated with this method will meet Chinese highest discharge standard as long as the routine biochemical treatment is applied thereafter.

Abstract: A communication system is enclosed. In one embodiment, the communication system includes a communication device configured to puts itself into an activated state or into a deactivated state at alternate times. The communication device receives time information in a first operating state of the activated state, takes the received time information as a basis for ascertaining the later time at which useful information is transmitted to the communication device, receives the useful information at the later time in a second operating state of the activated state, and with individual components of the communication device being able to be put into an activated state or into a deactivated state independently of one another.

Abstract: A system and method of controlling position of a pick-up head of an optical drive, including manipulating the position of the pick-up head as a primary variable in a cascade control scheme, and manipulating current flowing through the pick-up head as a secondary variable in the cascade control scheme.