Abstract: A holographic data storage system comprises an emitter system, a holographic recording medium, and an input waveguide network formed of one or more multimode optical waveguides. The holographic recording medium has multiple recording regions, each optically coupled to a corresponding one of multiple out-coupling regions of the input waveguide network, the holographic data storage system arranged to persistently write data of an input beam, received at any one of the out-coupling regions, to the corresponding recording region. A controller is coupled to at least one of the emitter system and at least one controllable guiding element of the input waveguide network and controls at least one optical characteristic of the input beam or the at least one guiding element, so as to guide the input beam from an in-coupling region to any selected one of the multiple out-coupling regions. Similar waveguide networks are provided for carrying reference and output beams.

Abstract: A heat-assisted magnetic recording (HAMR) head has a slider with a gas-bearing-surface (GBS). The slider supports a near-field transducer (NFT) with an output tip at the GBS and a main magnetic pole that has a recess in the NFT-facing surface that contains plasmonic material. The plasmonic recess has a front edge at the GBS that has a cross-track width equal to or less than the cross-track width of the widest portion of the NFT output tip, and a back edge recessed from the GBS. A thermal shunt is located between the NFT and the main pole to allow heat to be transferred away from the optical spot generated by the NFT output tip, and is in contact with a region of the plasmonic recess near the back edge.

Abstract: A multi-slope load/unload ramp for a hard disk drive includes an inner first portion having a non-horizontal first slope and an adjacent outer second portion having a different non-horizontal second slope. The first slope may be steeper than the second slope, and the ramp may further include a third portion adjacent to the second portion and also having a third slope steeper than the second slope, with the ramp configured for positioning the first and second portions to overlap the disk while the third segment may be in part outside the disk. The second slope may be steeper than the first slope, with the ramp configured for positioning the first portion to overlap the disk while the second portion may be in part outside of the disk. Hence, any slider rebound from the steeper portions would occur outside of the disk and avoid a slider-disk crash.

Abstract: A heat-assisted magnetic recording (HAMR) disk has a magnetic recording layer (typically a FePt chemically-ordered alloy), a seed-thermal barrier layer (typically MgO) below the recording layer, a heat-sink layer, and an optical-coupling multilayer of alternating plasmonic and non-plasmonic materials between the heat-sink layer and the seed-thermal barrier layer. Unlike a heat sink layer, the multilayer has very low in-plane and out-of-plane thermal conductivity and thus does not function as a heat sink layer. The multilayer's low thermal conductivity allows the multilayer to also function as a thermal barrier. Due to the plasmonic materials in the multilayer it provides excellent optical coupling with the near-field transducer (NFT) of the HAMR disk drive.

Abstract: A magnetic tape device. The angle ? formed by the axis of the element array of the magnetic head with respect to a width direction of the magnetic tape is changed during running of the magnetic tape in the magnetic tape device. In a case where predetermined storage is defined as one cycle, a maximum value of an absolute value of a difference between a servo band spacing obtained before performing the storage and a servo band spacing obtained after the storage of N cycles is defined as A, and N is set to 1, 2, 3, 4, or 5, a medium life calculated by a linear function of A and a logarithm loge T of T, that are derived from a value of A and a value of the logarithm loge T of total storage time T of the storage of N cycles is 5 years or longer.

Abstract: According to one embodiment, a magnetic disk device comprises an actuator, a controller that controls the actuator, a loop shaping filter connected in parallel with the controller, the loop shaping filter having a parameter for suppressing a rotation asynchronous disturbance affecting the actuator, the parameter of the loop shaping filter being determined using a transfer function from an output of the loop shaping filter to before an input of the rotation asynchronous disturbance, and a notch filter that suppresses mechanical resonance of the actuator.

Abstract: According to one embodiment, a magnetic disk device which includes two or more independently drivable actuator blocks and performs seek control with a low jerk in which a jerk that is a derivative of acceleration is limited, wherein in a state where a first actuator block is not accessing a data sector of a disk, a second actuator block that is not the first actuator block accesses the data sector of the disk by seek control with a high Jerk.

Abstract: A method reduces the effect of accelerating/decelerating an “aggressor actuator” in a multi-actuator drive on a “victim actuator” in the drive. Measurements of fractional-wedge timing-offsets for an aggressor head are used to adjust the aggressor actuator commands that are inputted to a victim disturbance feedforward signal generator when a timing offset exists between the currently-used aggressor head and the aggressor head that was used to measure transfer functions for determining victim feedforward signals. When such a timing offset is equivalent to a specific fraction of the time period separating servo wedges, values of the aggressor actuator commands that are inputted to the victim disturbance feedforward signal generator may be modified based on the specific fraction. Feedforward signals may be modified when a timing offset exists between and the current timing of the currently-used victim head and an original timing of the currently-used victim head.

Abstract: A file system 130 has a function of integrally managing a first recording region 9a in a first auxiliary storage device and a second recording region 9b in a second auxiliary storage device. A reception section 110 receives information indicating the type of the file to be recorded. A place information acquisition section 114 acquires information regarding a recording place corresponding to the received information indicating the type of the file. A metadata processing section 134 defines metadata regarding a recording place of the file in reference to the acquired information regarding the recording place. A recording processing section 132 records the file into the first recording region 9a and/or the second recording region 9b according to the defined metadata.

Abstract: According to one embodiment, a magnetic disk device includes a power supply, a magnetic disk, a magnetic head, a communication unit that is communicable with a host computer and transmits a signal to the host computer at a first interval, a power supply monitor, a volatile memory that stores data related to read/write processing on the magnetic disk by the magnetic head, a non-volatile memory, and a controller that controls the communication unit to start processing of backing up the data stored in the volatile memory to the non-volatile memory and transmit the signal at a second interval longer than the first interval if power supplied from the power supply is detected to be disconnected based on monitoring of the power supply monitor.

Abstract: Provided are a tape erase element, tape erase device, and method for forming a tape erase element to erase content of a tape medium. The tape erase element comprises a housing forming a gap extending along a length of an outer surface of the housing. The gap extends from the outer surface of the housing to open into an inner space formed within the housing. A magnet is positioned within the inner space of the housing and having a surface extending across the gap. The magnet produces a magnetic flux that extends through a tape contact zone extending across a portion of the outer surface of the housing and the gap to erase content on the tape medium as the tape guide rollers guide the tape medium across the housing through the tape contact zone.

Abstract: According to one embodiment, a disk device includes two magnetic disks opposing each other at intervals of 1.2 to 1.5 mm, and at least two suspension assemblies movable respectively between the two magnetic disks. Each of the suspension assemblies includes a base plate, a load beam extending from the base plate, a tab extending from a distal end of the load beam, a wiring member on the load beam and the base plate, including a gimbal portion, and a magnetic head on the gimbal portion, abutting on a dimple of the load beam via the gimbal portion. The ratio of a distance from a bendable location of the load beam to a center of the dimple with respect to a distance from the center of the dimple to a tip of the tab is 2.8 to 3.8.

Abstract: A recording head has a near-field transducer proximate a media-facing surface of the recording head. A waveguide overlaps and delivers light to the near-field transducer, the light having a near-infrared wavelength. Two subwavelength focusing mirrors are at an end of the waveguide proximate the media-facing surface. The subwavelength mirrors are on opposite crosstrack sides of the near-field transducer and separated from a peg of the near-field transducer by a gap. The subwavelength focusing mirrors each include a core having a first edge exposed at the media-facing surface. The core formed of a core material that is resistant to mechanical wear and corrosion, such as a dielectric or robust metal. A liner covers a second edge of the core facing the near-field transducer. The liner includes a plasmonic metal that is has a plasmonic frequency in the ultraviolet range.

Abstract: Various illustrative aspects are directed to a data storage device, comprising one or more disks; an actuator mechanism configured to position one or more heads proximate to one or more disk surfaces of the one or more disks; and one or more processing devices, comprising an actuator mechanism control system configured for controlling the actuator mechanism. The processing devices are configured to: apply coefficients for a multi-rate notch filter to a servo control loop; measure a multi-rate error rejection transfer function; determine whether a peak of the multi-rate error rejection transfer function is greater than a multi-rate error rejection transfer function threshold; and modify, responsively to determining that the peak of the multi-rate error rejection transfer function is not greater than the multi-rate error rejection transfer function threshold, the parameters of the multi-rate notch filter based at least in part on the peak of the multi-rate error rejection transfer function.

Abstract: The present disclosure generally relates to a tape drive including a tape head. The tape head comprises one or more modules, each module comprising a plurality of writers disposed in a first row, a plurality of readers disposed in a second row parallel to the first row, a first servo reader aligned with either the first row or the second row, and a second servo reader aligned in a third row parallel to the first and second rows. The first servo reader and the second servo reader are offset from one another in a first direction and in a second direction perpendicular to the first direction, the first direction being a cross-track direction. The first servo reader and the second servo reader are spaced apart in the first direction about 1 ?m to about 20 ?m.

Abstract: Various embodiments of the present disclosure provide a read/write device for a hard-disk memory system. The read/write device includes a fixed structure; a membrane region including a first and a second membrane, which are constrained to the fixed structure, and a central portion, interposed between the first and second membranes; a first and a second piezoelectric actuator, mechanically coupled, respectively, to the first and second membranes; and a read/write head, which is fixed to the central portion of the membrane region. The first and second piezoelectric actuators can be controlled so as to cause corresponding deformations of the first and second membranes, said deformations of the first and second membranes causing corresponding movements of the read/write head with respect to the fixed structure.

Abstract: A magnetic tape cartridge includes a case that accommodates a magnetic tape on which a plurality of servo bands and a plurality of data bands are formed, servo patterns being recorded in the servo bands, and a memory provided in the case. The memory stores servo pattern interval-related information related to a servo pattern interval determined for each of the plurality of data bands included in the magnetic tape. The servo pattern interval is commonly used for a plurality of division areas obtained by dividing the data band in a width direction of the magnetic tape, and is a representative interval between a first servo pattern and a second servo pattern.

Abstract: Various illustrative aspects are directed to a data storage device comprising: a voice coil motor (VCM) and one or more processing devices, configured to actuate the VCM, switch on measuring a back electromotive force (BEMF) from the VCM for intervals of an initial BEMF measurement that are free of spikes in the initial BEMF measurement, and process a measured BEMF signal from the intervals of the initial BEMF measurement that are free of spikes in a change of current term of the initial BEMF measurement.

Abstract: Systems and methods are disclosed for an actuator device or actuator control device to implement a low power savings mode. For example, a device can comprise an actuator arm including a first actuator and a second actuator, the second actuator configured to refine a movement of the actuator arm to a more precise position than use of merely the first actuator. A device can also comprise a control system configured to determine when the device is in an idle state and, when the device is in the idle state, disable the second actuator and perform a positional seek operation with the second actuator disabled. Power savings can occur from disabling the second actuator, which may also include disabling associated circuitry, such that it does not consume power or consumes a nominal (e.g., negligible or insignificant) amount of power during the associated seek operation.

Abstract: A heat-assisted magnetic recording head includes a near-field transducer (NFT). The NFT includes a near-field emitter configured to heat a surface of a magnetic disk, and a plasmonic disk. The plasmonic disk is coupled to the near-field emitter and includes rhodium or iridium.