Abstract: This application discloses a model training method, which may be applied to the field of artificial intelligence. The method includes: when training a first neural network model based on a training sample, determining N parameters from M parameters of the first neural network model based on a capability of affecting data processing precision by each parameter; and updating the N parameters. In this application, on a premise that it is ensured that the data processing precision of the model meets a precision requirement, because only N parameters in M parameters in an updated first neural network model are updated, an amount of data transmitted from a training device to a terminal device can be reduced.

Abstract: A device and method for detecting an absolute multi-turn rotation angle. The device includes a housing, a cover plate and a rotating shaft. The rotating shaft is fixed with a main gear, which is meshed with driven gears including a large driven gear and a small driven gear. The main gear is externally meshed with the large driven gear. The driven gears are connected with a two-stage speed reduction device which enables the rotating shaft to rotate multiple circles to slow down to a circle-number gear and enables the circle-number gear to rotate one circle only. Both driven gears and the circle-number gear are provided with bearings. The bearings have magnets therein, and the two magnets are relatively fixed with the driven gears and the circle-number gear, respectively. The top edges of the bearings fit with a printed circuit board, angle sensing chips which are fixed on the printed circuit.

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: 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: 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 method for servoing when reading out a recorded holographic disk or recording in a preformatted disk includes detecting a primary signal of a reflected primary beam from a target data track of a target data layer of the disk, wherein the primary beam of radiation has a first wavelength; comparing a power measurement of the primary signal with a threshold value of power; detecting a tracking signal of a reflected tracking beam from a reference layer of the disk in an event that the power measurement of the primary signal is below the threshold value, wherein the tracking beam of radiation has a second wavelength; generating a servo error signal based upon the primary signal or the tracking signal; actuating an optical sub-system based upon either of the primary servo error signal or the tracking servo error signal such that the primary beam focuses on the target data layer.

Abstract: A sensor system for measuring a clearance parameter between a stationary component and a rotating component of a rotating machine is provided. The system includes a clearance sensor to output a clearance measurement signal. A sensor memory is attached to the sensor for storing a first sensor information. A second sensor information is stored in a electronics interface memory. The first and the second sensor information are read and the clearance sensor is matched with a respective plurality of calibration data by an electronic interface based on the first and the second sensor information.

Abstract: 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.

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: Techniques are provided for using a multi-stage actuator to actuate one or more optical components of an optical head. The multi-stage actuator includes a cross-layer displacement component which actuates an optical component to change the beam focus in a displacement range corresponding to the thickness of the data layers in a holographic disk, such that a beam is impinged on the target data layer. The multi-stage actuator also includes a intra-layer focusing component which actuates the optical component in a smaller range to focus the beam on the target data position. The cross-layer displacement component and the intra-layer focusing component may each include more than one actuator. In some embodiments, the focusing component also actuates the optical component in a tilting motion to compensate for movement or imperfections of the disk during a reading or recording process.

Abstract: Techniques are provided for increasing storage capacity in a holographic storage system. While typical holographic storage systems involve binary storage for each data position in a holographic disk, present techniques involve storing data such that more than two data levels may be recorded in each data position. In some embodiments, a recording beam directed to the disk may be adjusted to different power levels depending on the data level to be recorded. Furthermore, the recording time at a data position may be adjusted to increase the energy directed to the data position by increasing the amount of time the recording beam is impinged on the data position. Embodiments are suitable for different types of holographic storage, including dye-based medium.

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: 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: Self-calibration of a multiple channel clearance sensor system, which in one embodiment includes at least one sensor for measuring at least one clearance parameter signal between a stationary object and a rotating object of a rotating machine. The sensor output is processed as a clearance parameter by an offset correction section configured to determine an offset error in the clearance parameter signal which is used by a level shifter. The level shifter is also switchably coupled to the clearance parameter signal wherein the output of the level shifter, which may be amplified and digitally converted, is processed by a signal level analyzer to determine a channel gain 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: 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: Techniques are provided for increasing storage capacity in a holographic storage system. While typical holographic storage systems involve binary storage for each data position in a holographic disk, present techniques involve storing data such that more than two data levels may be recorded in each data position. In some embodiments, a recording beam directed to the disk may be adjusted to different power levels depending on the data level to be recorded. Furthermore, the recording time at a data position may be adjusted to increase the energy directed to the data position by increasing the amount of time the recording beam is impinged on the data position. Embodiments are suitable for different types of holographic storage, including dye-based medium.

Abstract: Techniques are provided for using a multi-stage actuator to actuate one or more optical components of an optical head. The multi-stage actuator includes a cross-layer displacement component which actuates an optical component to change the beam focus in a displacement range corresponding to the thickness of the data layers in a holographic disk, such that a beam is impinged on the target data layer. The multi-stage actuator also includes a intra-layer focusing component which actuates the optical component in a smaller range to focus the beam on the target data position. The cross-layer displacement component and the intra-layer focusing component may each include more than one actuator. In some embodiments, the focusing component also actuates the optical component in a tilting motion to compensate for movement or imperfections of the disk during a reading or recording process.

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.