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: The present techniques provide methods and systems reading a data bit of interest on an optical data disc with a reduced error rate. The data bit estimation may be improved by reducing deterministic noise resulting from an optical reader system and/or the optical data disc. The reader may adjust the position of a detector to detect light scattered from the disc based on parameters of known noise sources. In one embodiment, the detector may be moved vertically in relation to the data bit of interest on the optical disc. In another embodiment, more than one detector may be used to detect light scattered from a data bit of interest. In embodiments, the positioning of the detector(s) may be based on system or disc parameters, and the detected scatterings may provide a data reading, improved for an optical return from a present micro-hologram.

Abstract: An optical article is provided. The optical article includes a first layer. The first layer includes an active holographic layer configured to store holographic data. The first layer has a first surface and a second surface. A second layer includes a low birefringence material. The second layer also has a first surface and a second surface. Guide grooves are present in any one of the first layer or the second layer. In certain embodiments, the article may further include a reflective layer, an anti-reflective layer, a barrier layer, and a combination thereof.

Abstract: The present techniques provide methods and systems reading a data bit of interest on an optical data disc with a reduced error rate. The data bit estimation may be improved by reducing deterministic noise resulting from an optical reader system and/or the optical data disc. The reader may adjust the position of a detector to detect light scattered from the disc based on parameters of known noise sources. In one embodiment, the detector may be moved vertically in relation to the data bit of interest on the optical disc. In another embodiment, more than one detector may be used to detect light scattered from a data bit of interest. In embodiments, the positioning of the detector(s) may be based on system or disc parameters, and the detected scatterings may provide a data reading, improved for an optical return from a present micro-hologram.

Abstract: A method of making a holographic data storage medium is provided. The method comprises: (a) providing an optically transparent substrate comprising at least one photochemically active dye; and (b) irradiating the optically transparent substrate at least one wavelength at which the optically transparent substrate has an absorbance in a range from about 0.1 to 1, to produce a modified optically transparent substrate comprising at least one optically readable datum and at least one photo-product of the photochemically active dye. The at least one wavelength is in a range from about 300 nanometers to about 800 nanometers. The optically transparent substrate is at least 100 micrometers thick, and comprises the photochemically active dye in an amount corresponding to from about 0.1 to about 10 weight percent based on a total weight of the optically transparent substrate.

Abstract: A system and method of operating a dual-beam detection system of a holographic data storage disc, including: impinging a data beam on a data layer of the holographic data storage disc; impinging a tracking beam on a tracking element of the holographic data storage disc; detecting a reflection of the tracking beam from the tracking element; and coordinating position of the data beam relative to the tracking beam.

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 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: 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.

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.

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: A data storage device including: a plastic substrate having a plurality of volumes arranged along a plurality of depth-extending, concentrically stacked tracks; and, a plurality of micro-holograms each contained in a corresponding one of the tracks; wherein, the presence or absence of a micro-hologram in each of said volumes is indicative of a corresponding portion of data stored.

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: 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: A data storage device comprises a substrate having oppositely disposed surfaces and a plurality of volumes arranged along tracks between the surfaces; a plurality of micro-holograms each contained in a corresponding one of the volumes; and, at least one groove in at least one of the surfaces and being operative to diffract light through the at least one surface and into the volumes; wherein, the presence or absence of a micro-hologram in a stacked layer in each of the volumes is indicative of a corresponding portion of data stored.

Abstract: A system for use with a data storage media having at least one groove proximate a surface thereof and a plurality of volumes therein, including: objective lensing; a first tracking error detector optically coupled to the objective lensing and being responsive to reflections from the at least one groove; a first actuator coupled and responsive to the first tracking error detector; a second tracking error detector optically coupled to the objective lensing and responsive to reflections from micro-holograms contained in at least some of the volumes; and, a second actuator coupled and responsive to the second tracking error detector; wherein the first and second actuators cooperate to selectively position the objective lensing to focus a light beam into a target one of the volumes.

Abstract: The present techniques present methods and systems for increasing a data reading rate on optical data disks using a single reading head. The methods take advantage of the difference between a mean focal distance (MFD), or minimum spacing that the detector can distinguish between bits, and the minimum separation of bits in a single track to increase the reading speed. As the bits may be more closely spaced across adjacent tracks or layers, these techniques may be used to increase the reading speed of the disk. Specifically, the data symbols that make up a single bit-stream may be stored in a pattern horizontally across adjacent tracks, or vertically across adjacent layers. Accordingly, the focal point of the detector is scanned across the disk in the same pattern to read the individual data symbols.

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: 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: 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.