Abstract: A data storage device includes a laser diode that heats an area of a disk near the read/write head. To mitigate mode hopping, the laser diode is preheated using the laser diode itself, such as by applying a reverse bias to the laser diode, during an interruption in writing of data to the disk. The laser diode is preheated to a temperature that maintains operation of the laser diode within a middle portion of a preselected gain mode and away from abrupt shifts in gain modes.

Abstract: A data storage device may include a media comprising a magnetic recording layer and a heat-assisted magnetic recording (HAMR) head for writing to the magnetic recording layer, the HAMR head comprising: a waveguide, a main pole comprising a main-pole surface facing the magnetic recording layer, a near-field transducer (NFT) situated between the main pole and the waveguide, and a transparent overcoat. The NFT comprises a main body and a micropillar. The micropillar comprises a micropillar surface facing the magnetic recording layer. A first distance between the micropillar surface and the media is less than a second distance between the main-pole surface and the media. The transparent overcoat is situated on the main-pole surface and the micropillar surface.

Abstract: A data storage device may include one or more disks, an actuator arm assembly comprising one or more magnetic recording heads, at least one laser diode, and one or more processing devices configured to: set the at least one laser diode to a first temperature; apply a first forward bias and supply a first current to the at least one laser diode such that it is in a lasing state; measure, for the at least one laser diode, a first output corresponding to the first temperature and current; set the at least one laser diode to a second temperature; measure, for the at least one laser diode, a second output corresponding to the second temperature and the first current; and determine an output profile for the at least one laser diode, based at least in part on the respective output at the first temperature and the second temperature.

Abstract: A data storage device may include a disk, an actuator arm assembly comprising a magnetic recording head, a laser diode, and one or more processing devices configured to: initiate a write operation, wherein the write operation is associated with a first temperature of the laser diode; measure a resistance of the laser diode, wherein the resistance corresponds to a temperature of the laser diode; detect, based at least in part on measuring the resistance, a change in the temperature of the laser diode relative to the first temperature; and in response to detecting the change, adjust the temperature of the laser diode during the write operation.

Abstract: A data storage device may include one or more disks, an actuator arm assembly comprising one or more magnetic recording heads, a laser diode positioned inside a laser diode cavity, and one or more processing devices configured to initiate a write operation, wherein initiating the write operation comprises activating a magnetic recording head corresponding to the laser diode, and applying a forward bias to the laser diode; apply a first reverse bias to the laser diode during at least one intervening event; and transition from applying the first reverse bias to the at least one laser diode to applying the forward bias to the at least one laser diode.

Abstract: A data storage device may include a media comprising a magnetic recording layer and a heat-assisted magnetic recording (HAMR) head for writing to the magnetic recording layer, the HAMR head comprising: a waveguide, a main pole comprising a main-pole surface facing the magnetic recording layer, a near-field transducer (NFT) situated between the main pole and the waveguide, and a transparent overcoat. The NFT comprises a main body and a micropillar. The micropillar comprises a micropillar surface facing the magnetic recording layer. A first distance between the micropillar surface and the media is less than a second distance between the main-pole surface and the media. The transparent overcoat is situated on the main-pole surface and the micropillar surface.

Abstract: A data storage device may include one or more disks, an actuator arm assembly comprising one or more disk heads, at least one laser diode positioned inside a corresponding laser diode cavity, a preamplifier, and one or more processing devices. The one or more processing devices are configured to: generate a reverse bias; apply, using the preamplifier, the reverse bias to the at least one laser diode to preheat a corresponding laser diode cavity to a target temperature prior to a write operation; control transition of the preamplifier from applying the reverse bias to applying a forward bias to the at least one laser diode; and activate the at least one laser diode to begin the write operation.

Abstract: Various illustrative aspects are directed to a data storage device, comprising one or more disks; an actuator system configured to position a selected head among one or more heads proximate to a corresponding disk surface among the one or more disks; and one or more processing devices. The selected head comprises a write element, an assistive energy emitter, an energizing interface coupled to the assistive energy emitter, and a detector. The assistive energy emitter is driven separately from driving of the write element. The one or more processing devices are configured to detect, via the detector, an energy anomaly at the energizing interface; detect, in response to detecting the energy anomaly, whether a previously written track yields an anomalous readback signal; and rewrite, in response to detecting that the previously written track yields an anomalous readback signal, data designated for the previously written track to the previously written track.

Abstract: A data storage device may include one or more disks, an actuator arm assembly comprising one or more magnetic recording heads, a laser diode positioned inside a laser diode cavity, and one or more processing devices configured to initiate a write operation, wherein initiating the write operation comprises activating a magnetic recording head corresponding to the laser diode, and applying a forward bias to the laser diode; apply a first reverse bias to the laser diode during at least one intervening event; and transition from applying the first reverse bias to the at least one laser diode to applying the forward bias to the at least one laser diode.

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 a corresponding disk surface of the one or more disks; and one or more processing devices. The one or more processing devices are configured to receive signals indicative of conditions of a write operation by the selected head. The one or more processing devices are further configured to determine, based on the signals, a verification status indicating whether the write operation was successful. The one or more processing devices are further configured to output the verification status within a selected time limit.

Abstract: The present disclosure generally relate to tape assembly implementations for magnetic recording devices, such as tape embedded drives (TEDs). In one or more embodiments, a first reel and a second reel are mounted at stationary positions. One or more of the first reel and/or the second reel includes a hub mounted to a spindle, and a single flange extending relative to the hub. In one or more embodiments, one or more of a first reel and/or a second reel each includes a flangeless hub mounted to a spindle.

Abstract: A data storage device may include one or more disks, an actuator arm assembly comprising one or more disk heads, at least one laser diode positioned inside a corresponding laser diode cavity, a preamplifier, and one or more processing devices. The one or more processing devices are configured to: generate a reverse bias; apply, using the preamplifier, the reverse bias to the at least one laser diode to preheat a corresponding laser diode cavity to a target temperature prior to a write operation; control transition of the preamplifier from applying the reverse bias to applying a forward bias to the at least one laser diode; and activate the at least one laser diode to begin the write operation.

Abstract: The present disclosure generally relates to a tape drive having a regenerative braking system. The tape drive comprises a first reel; a first spindle coupled to the first reel; a first motor coupled to the first spindle, wherein the first motor is configured to rotate the first spindle; a second reel; a second spindle coupled to the second reel; a second motor coupled to the second spindle, wherein the second motor is configured to rotate the second spindle; and a regenerative braking circuit coupled to the first motor and the second motor, wherein during a braking of the motors, the regenerative braking circuit and the motors convert a mechanical energy of the motors to electrical energy for a power storage mechanism, thereby providing resistance to the rotation of the spindles.

Abstract: The present disclosure generally relates to a multi-disk drive comprising a plurality of media surfaces and a plurality of heads, wherein a head of the plurality of heads is configured to be actuated over each surface of the plurality of media surfaces. The multi-disk drive further comprises control circuitry configured to write data to a first media surface of the plurality of media surfaces using a first head of the plurality of heads, and after all of an available memory of the first media surface has been filled, write data to a second media surface of the plurality of media surfaces using a second head of the plurality of heads. The control circuitry is further configured to permanently disable write access to one or more media surfaces of the plurality of media surfaces, while continuing to permit read access to the plurality of media surfaces.

Abstract: The present disclosure relates to pretreating a magnetic recording head. For a HAMR head, a NFT is present. Current can be applied to the NFT to condition the NFT. The current is applied in one of three ways: slowly ramping up the current from a starting level below a level capable of writing data to the optical laser current over a predetermined period of time, applying the current at a fixed value below the optical laser current for the predetermined period of time, or slowly ramping up the current from a starting level below a level capable of writing data to the optical laser current over the predetermined period of time while also intermittently removing the current. By conditioning the NFT in such a manner, the HAMR head can avoid thermal shock and thermal fatigue and thus increase the lifetime of the magnetic media drive.

Abstract: The present disclosure generally relates to a tape drive having a regenerative braking system. The tape drive comprises a first reel; a first spindle coupled to the first reel; a first motor coupled to the first spindle, wherein the first motor is configured to rotate the first spindle; a second reel; a second spindle coupled to the second reel; a second motor coupled to the second spindle, wherein the second motor is configured to rotate the second spindle; and a regenerative braking circuit coupled to the first motor and the second motor, wherein during a braking of the motors, the regenerative braking circuit and the motors convert a mechanical energy of the motors to electrical energy for a power storage mechanism, thereby providing resistance to the rotation of the spindles.

Abstract: The present disclosure generally relate to tape assembly implementations for magnetic recording devices, such as tape embedded drives (TEDs). In one or more embodiments, a first reel and a second reel are mounted at stationary positions. One or more of the first reel and/or the second reel includes a hub mounted to a spindle, and a single flange extending relative to the hub. In one or more embodiments, one or more of a first reel and/or a second reel each includes a flangeless hub mounted to a spindle.

Abstract: The present disclosure generally relates to a multi-disk drive comprising a plurality of media surfaces and a plurality of heads, wherein a head of the plurality of heads is configured to be actuated over each surface of the plurality of media surfaces. The multi-disk drive further comprises control circuitry configured to write data to a first media surface of the plurality of media surfaces using a first head of the plurality of heads, and after all of an available memory of the first media surface has been filled, write data to a second media surface of the plurality of media surfaces using a second head of the plurality of heads. The control circuitry is further configured to permanently disable write access to one or more media surfaces of the plurality of media surfaces, while continuing to permit read access to the plurality of media surfaces.

Abstract: Example preamplifier circuits, data storage devices, and methods to provide a preamplifier circuit with separate read and write power channels are described. The preamplifier circuit may include a write driver circuit configured to send a write signal to a writer element of a data storage device and a read driver circuit configured to receive a read signal from a reader element of the data storage device. The write driver circuit may receive a write power signal through a write power channel of a bus interface and the read driver circuit may receive a read power signal through a read power channel of the bus interface, where the write power signal and the read power signal are different. In some configurations, the different read and write power signals may be received from a switching regulator on the printed circuit board that mounts other data storage device electronics, such as the drive controller circuit and/or read/write channel circuit.

Abstract: Example systems, data storage devices, and methods to provide long-term spacing compensation for heat assisted magnetic recording are described. The data storage device includes a storage medium with data tracks and a head that can be positioned for reading and writing those tracks. The head includes a laser for heat assisted magnetic recording and a fly height actuator. Based on the operation of the laser, both a short-term fly height compensation parameter and a long-term fly height compensation parameter are determined based on different temperature state models. The operating power of the fly height actuator is determined, at least in part, based on the short-term and long-term height compensation parameters.