Abstract: A storage device controller addresses consecutively-addressed portions of incoming data to consecutive data tracks on a storage medium and writes the consecutively-addressed portions to the consecutive data tracks in a non-consecutive track order. In one implementation, the storage device controller reads the data back from the consecutive data tracks in a consecutive address order in a single sequential read operation.

Abstract: A storage device disclosed herein stores data on a storage media using interlaced magnetic recording (IMR) and it includes a storage controller configured to determine power levels applied to the power source such that power levels applied to heat various tracks can be different from each other. An implementation of the storage device determines the track density, linear densities and power levels for even and odd tracks in IMR HAMR for the storage media.

Abstract: A storage device disclosed herein stores data on a storage media using interlaced magnetic recording (IMR) and it includes a storage controller configured to determine power levels applied to the power source such that power levels applied to heat various tracks can be different from each other. An implementation of the storage device determines the track density, linear densities and power levels for even and odd tracks in IMR HAMR for the storage media.

Abstract: A signal is recorded over at least part of a track a heat-assisted recording medium via a heat-assisted magnetic recording head. Symmetry of a cross-track profile of the recorded signal is determined, and the recording head is qualified based on the symmetry of the cross-track profile.

Abstract: A storage device includes a data degradation management module that tracks a risk of data degradation by incrementing a track write counter of a first data track responsive to each data write command to a second data track, such as a data track directly adjacent to the first data track. If a count of the track write counter exceeds a count threshold, one or more post-write scan operations are performed to assess and/or repair data degradation of the first data track.

Abstract: A data storage device and associated methods may provide at least a data storage medium that is separated from a heat assisted magnetic recording data writer and is connected to a controller. The controller can be configured to change a laser power of the heat assisted magnetic recording data writer in response to a tested bit error rate of a median data track of a plurality of adjacent data tracks reaching an identified threshold.

Abstract: A data storage device may employ a heat assisted magnetic recording data writer separated from a plurality of data bits stored on a media surface of a data storage medium. At least one controller and a prediction circuit that is connected to the heat assisted magnetic recording data writer can be configured to remap the media surface in response to a predicted heat assisted magnetic recording data writer failure.

Abstract: A method of controlling laser output in a heat assisted magnetic recording device can be performed by control circuitry in a data storage device. The method includes measuring a temperature, measuring laser output power of a laser, determining a power error by subtracting an optimal laser output power from the measured laser output power and comparing the power error to at least one threshold to determine whether an applied current to the laser needs to be adjusted. The at least one threshold is related to how great the power error can be while maintaining the integrity of data on a recording medium.

Abstract: At least one laser input current is applied to a laser in a heat assisted magnetic recording device. Laser output power of the laser is measured at the at least one applied laser current. A relationship is characterized amongst temperature, applied laser input current and laser output power. Laser current is set to an optimal laser current as determined at manufacturing. A metric of recording performance is measured to determine if the relationship is acceptable.

Abstract: A circuit may be configured to reduce the power consumption and extend the life of a near field transducer of a heat-assisted magnetic recording (HAMR) device by pulsing a laser. The current that drives the laser may be of a frequency and magnitude so as to approximate the value of a continuous current in a continuous, non-pulsed laser. A system on chip (SOC), which may include a HAMR channel, can generate a laser data signal that may be synchronous with, and offset from, a write signal by a certain period of time, and may calculate certain parameters such as peak current and pulse width that may be applied to the signals in a preamp. The preamp signals can be used to program data to a disc medium.

Abstract: A transducer is configured to interact with a magnetic storage medium, a first channel comprises a first sensor and first circuitry configured to adjust a plurality of first channel parameters, and a second channel comprises a second sensor and second circuitry configured to adjust a plurality of second channel parameters. The first and second channel parameters are independently adjustable by the first and second circuitry, respectively. A detector is coupled to the first and second channels, and configured to detect a head-medium interface event.

Abstract: An apparatus comprises a write transducer, an energy source, and a controller. The write transducer is configured to write data to a magnetic recording medium, and the energy source is configured to heat the magnetic recording medium while it is being written to by the write transducer. The controller is coupled to the write transducer and configured to adjust at least an operating power of the energy source to selectably cause bits having variable bit aspect ratios to be written to the magnetic media.

Abstract: An apparatus includes a write element configured to apply a magnetic field to write data on a portion of a heat-assisted magnetic recording media in response to an energizing current. An energy source is configured to heat the portion of the media being magnetized by the write element. A preheat energizing current is applied to the write element during an interval before writing the data to the portion of the media. The preheat energizing current does not cause data to be written to the media and brings at least one of the write element and driver circuitry into thermal equilibrium prior to writing the data on the portion.

Abstract: An apparatus comprises a write transducer, an energy source, and a controller. The write transducer is configured to write data to a magnetic recording medium, and the energy source is configured to heat the magnetic recording medium while it is being written to by the write transducer. The controller is coupled to the write transducer and configured to adjust at least an operating power of the energy source to selectably cause bits having variable bit aspect ratios to be written to the magnetic media.

Abstract: A transducer is configured to interact with a magnetic storage medium, a first channel comprises a first sensor and first circuitry configured to adjust a plurality of first channel parameters, and a second channel comprises a second sensor and second circuitry configured to adjust a plurality of second channel parameters. The first and second channel parameters are independently adjustable by the first and second circuitry, respectively. A detector is coupled to the first and second channels, and configured to detect a head-medium interface event.

Abstract: An apparatus includes an optical pathway configured to deliver energy to heat a magnetic recording medium via a slider body. The optical pathway generates heat in the slider body when delivering energy to the magnetic recording medium. The apparatus includes a compensating heater with a thermal characteristic that matches a thermal characteristic of the optical pathway. The compensating heater is activated at least part of the time when the optical pathway is not delivering the energy to the magnetic recording medium.

Abstract: An apparatus comprises a write transducer, an energy source, and a controller. The write transducer is configured to write data to a magnetic recording medium, and the energy source is configured to heat the magnetic recording medium while it is being written to by the write transducer. The controller is coupled to the write transducer and configured to adjust at least an operating power of the energy source to selectably cause bits having variable bit aspect ratios to be written to the magnetic media.

Abstract: A transducer is configured to interact with a magnetic storage medium, a first channel comprises a first sensor and first circuitry configured to adjust a plurality of first channel parameters, and a second channel comprises a second sensor and second circuitry configured to adjust a plurality of second channel parameters. The first and second channel parameters are independently adjustable by the first and second circuitry, respectively. A detector is coupled to the first and second channels, and configured to detect a head-medium interface event.

Abstract: An apparatus includes a write element configured to apply a magnetic field to write data on a portion of a heat-assisted magnetic recording media in response to an energizing current. An energy source is configured to heat the portion of the media being magnetized by the write element. A preheat energizing current is applied to the write element during an interval before writing the data to the portion of the media. The preheat energizing current does not cause data to be written to the media and brings at least one of the write element and driver circuitry into thermal equilibrium prior to writing the data on the portion.

Abstract: A device includes a body, a waveguide, and a near field transducer (NFT). The body has opposed first and second surfaces. The waveguide is adapted to receive light and convey the light to a distal end of the waveguide. The NFT is disposed proximate the distal end, and it has an output end proximate the first surface of the body. The device further includes a surface-emitting distributed feedback (SE-DFB) laser that is mounted on and attached to the body and positioned to inject laser light into the waveguide. The device may be a recording head, and the laser, the waveguide, and the NFT may cooperate to provide electromagnetic heating to a substrate for heat assisted magnetic recording.