A diamond probe is suitable to be attached to an Atomic Force Microscope and is created with a tip that incorporates a one or more Nitrogen Vacancy (NV) centers located near the end of the tip. The probe arm acts as an optical waveguide to propagate the emission from the NV center with high efficiency and a beveled end directs excitation light to the NV center and directs photoluminescence light emanating from the NV center into the probe arm. The probe tip is scanned over an area of a sample with an electric charge, such as a field effect transistor or flash memory. Optically Detected Spin Resonance (ODMR) is measured as the probe tip is scanned over the area of the sample, from which a characteristic of the area of the sample with the electric charge may be determined.

A system for compensating for heat induced transient phase shift in a heat assisted magnetic recording system. A heat assisted magnetic data recording system includes a near field thermal transducer that locally heats the media during writing. The thermal transducer, when activated, results in a change in size of a magnetic transition written to the magnetic media. This change in size of the thermal transition results in a transient phase shift of the data recorded on the magnetic media. The system includes circuitry for predetermining an anticipated amount of transient phase shift and adjusting a subsequent read signal to compensate for the known transient phase shift, thereby eliminating signal errors resulting from the transient phase shift.

An apparatus comprises a slider having an air bearing surface (ABS) and a near-field transducer (NFT) at or near the ABS. An optical waveguide is configured to couple light from a laser source to the NFT. A resistive sensor comprises an ABS section situated at or proximate the ABS and a distal section extending away from the ABS to a location at least lateral of or behind the NFT. The resistive sensor is configured to detect changes in output optical power of the laser source and contact between the slider and a magnetic recording medium.

A data storage device is disclosed comprising a first head actuated over a first disk surface, wherein the first head comprises a laser configured to heat the first disk surface while writing data to the first disk surface. A write power is applied to the laser when executing a first write operation, and the first write operation is paused when a transient increase in the output power of the laser is detected. In another embodiment, a write-verify of the written data is executed when a transient decrease in the output power of the laser is detected.

A sequential storage media system may include a head for reading or writing data to sequential storage media and a controller communicatively coupled to the head. The controller may be configured to control winding of a tape comprising sequential storage media and cleaning media between reels of a cartridge comprising the tape in order to clean a head of a sequential storage media system by passing the cleaning media over the head, after cleaning the head of the sequential storage media system, monitor a bit error rate of input/output communication between the head and the sequential storage media, and repeat the cleaning and the monitoring steps responsive to the bit error rate exceeding a threshold.

A sequential storage media system may include a head for reading or writing data to sequential storage media and a controller communicatively coupled to the head. The controller may be configured to control winding of a tape comprising cleaning media between reels of a cartridge comprising the tape in order to determine an occurrence of an event indicative of a need to clean a head of a sequential storage media system, issue to a user an indication of the occurrence of the event, determine an amount of cleaning for the head based on a bit error rate of input/output communication associated with the head, and responsive to receiving a cleaning cartridge in the sequential storage media system, clean the head of a sequential storage media system in accordance with the amount of cleaning by passing cleaning media of a cartridge over the head.

A sequential storage media system may include a head for reading or writing data to sequential storage media and a controller communicatively coupled to the head. The controller may be configured to control winding of a tape comprising sequential storage media and cleaning media between reels of a cartridge comprising the tape in order to clean a head of a sequential storage media system by passing the cleaning media over the head, after cleaning the head of the sequential storage media system, monitor a bit error rate of input/output communication between the head and the sequential storage media, and repeat the cleaning and the monitoring steps responsive to the bit error rate exceeding a threshold.

A sequential storage media system may include a head for reading or writing data to sequential storage media and a controller communicatively coupled to the head. The controller may be configured to control winding of a tape comprising cleaning media between reels of a cartridge comprising the tape in order to determine an occurrence of an event indicative of a need to clean a head of a sequential storage media system, issue to a user an indication of the occurrence of the event, determine an amount of cleaning for the head based on a bit error rate of input/output communication associated with the head, and responsive to receiving a cleaning cartridge in the sequential storage media system, clean the head of a sequential storage media system in accordance with the amount of cleaning by passing cleaning media of a cartridge over the head.

A method includes moving a heat-assisted magnetic recording head relative to a magnetic recording medium comprising a plurality of tracks, the head comprising a reader and a writer including a near-field transducer (NFT) optically coupled to a laser diode, the writer comprising a center which is laterally offset relative to a center of the reader to define a writer-reader offset (WRO) therebetween. Patterns are written to a particular track at a plurality of laser diode current levels. The patterns are read and a WRO value is calculated at a peak amplitude position for each of the laser diode current levels. A slope of the WRO values is determined with the laser current diode levels. A health condition of the NFT is determined by determining if the slope is greater than a predetermined threshold indicative of non-uniform activation across the NFT.

A data storage device is disclosed comprising a disk, a head for accessing the disk, and a sensor for generating an alternating sensor signal. The sensor is disconnected from an input of a sensing circuit and while the sensor is disconnected an alternating calibration signal is injected into the input of the sensing circuit, wherein the alternating calibration signal comprises a predetermined offset and amplitude. A response of the sensing circuit to the alternating calibration signal is evaluated to detect at least one of an offset and a gain of the sensing circuit.

A disk drive is operable to determine degradation associated with writing to a disk surface by a head which has written existing data at a first areal density. A second areal density less than the first areal density is determined that remediates the degradation. The disk drive performs subsequent writes to the disk surface at the second areal density, and continues to read the existing data at the first areal density.

A disk drive is operable to determine degradation associated with writing to a disk surface by a head which has written existing data at a first areal density. A second areal density less than the first areal density is determined that remediates the degradation. The disk drive performs subsequent writes to the disk surface at the second areal density, and continues to read the existing data at the first areal density.