Abstract: A method and system for determining slider-disk contact in a hard-disk drive (HDD) that has dual independent heaters for thermal fly-height control, and dual embedded contact sensors, includes dithering power to the two heaters at different frequencies. The HDD has the two contact sensors electrically connected to provide a single combined output signal in response to the dithering. The single combined output signal is analyzed to detect two signals at the two different frequencies. When either detected signal exceeds a predetermined touchdown threshold value, the values of heater power for the two heaters are recorded, indicating that that combination of heater power values corresponds to slider-disk contact.

Abstract: Disclosed herein are write heads for data storage devices, methods for making and using such write heads, and data storage devices comprising such write heads. A write head comprises a near-field transducer (NFT), a thermal sensor, and a shield disposed between the NFT and the thermal sensor, wherein the shield comprises a magnetic or conductive material, such as, for example, Cu, Ag, Au, Al, Rh, Ti, Cr, Mo, Fe, Co, or Ni or an alloy that includes Cu, Ag, Au, Al, Rh, Ti, Cr, Mo, Fe, Co, and/or Ni. In some embodiments, the thermal sensor comprises a first lead and a second lead, and the shield is connected to the first lead but not the second lead to provide heat sinking for the shield.

Abstract: Embodiments disclosed herein generally relate to a method for monitoring optical power in a HAMR device. In one embodiment, the method includes enhancing a thermal sensor bandwidth through advanced electrical detection techniques. The advanced electrical detection techniques include obtaining calibration waveform data for a thermal sensor by calibrating the thermal sensor, obtaining real-time waveform data for the thermal sensor that may deviate from the calibration waveform data, updating the calibration waveform data to include the real-time waveform data, repeating obtaining real-time waveform data and updating the calibration waveform data during writing operations. By updating the calibration waveform data, the bandwidth of the thermal sensor is determined by a fixed sampling time interval, and the thermal sensor rise time to steady state would not be a limitation to its response time.

Abstract: Disclosed herein are write heads for data storage devices, methods for making and using such write heads, and data storage devices comprising such write heads. A write head comprises a near-field transducer (NFT), a thermal sensor, and a shield disposed between the NFT and the thermal sensor, wherein the shield comprises a magnetic or conductive material, such as, for example, Cu, Ag, Au, Al, Rh, Ti, Cr, Mo, Fe, Co, or Ni or an alloy that includes Cu, Ag, Au, Al, Rh, Ti, Cr, Mo, Fe, Co, and/or Ni. In some embodiments, the thermal sensor comprises a first lead and a second lead, and the shield is connected to the first lead but not the second lead to provide heat sinking for the shield.

Abstract: Embodiments disclosed herein generally relate to a method for monitoring optical power in a HAMR device. In one embodiment, the method includes enhancing a thermal sensor bandwidth through advanced electrical detection techniques. The advanced electrical detection techniques include obtaining calibration waveform data for a thermal sensor by calibrating the thermal sensor, obtaining real-time waveform data for the thermal sensor that may deviate from the calibration waveform data, updating the calibration waveform data to include the real-time waveform data, repeating obtaining real-time waveform data and updating the calibration waveform data during writing operations. By updating the calibration waveform data, the bandwidth of the thermal sensor is determined by a fixed sampling time interval, and the thermal sensor rise time to steady state would not be a limitation to its response time.

Abstract: A data storage device is disclosed comprising a head actuated over a disk, wherein the head comprises a first sensor element and a second sensor element. When configured into a first single-ended mode, a bias signal is applied to the first sensor element to generate a first single-ended output signal based on a response of the first sensor element, and when configured into a second single-ended mode, the bias signal is applied to the second sensor element to generate a second single-ended output signal based on a response of the first sensor element. When configured into a differential mode, the bias signal is concurrently applied to the first sensor element and the second sensor element to generate a differential output signal based on a response of the first sensor element and the second sensor element.

Abstract: A data storage device is disclosed comprising a head actuated over a disk, wherein the head comprises a laser configured to heat the disk while writing data to the disk. A write power is applied to the laser in order to write data to the disk during a write operation. A determination is made as to whether the laser power should be in an off state after the write operation. After the write operation, the laser power is gradually decreased to the off state based on a first decrease function.

Abstract: A method for magnetic data recording that calibrates for magnetic thermal protrusion of elements of a magnetic data recording system. The method involves performing a series of burst mode magnetic data writings using a magnetic recording head that includes a write element, a thermal fly height control element and a near field transducer. The burst mode writings are performed at various levels of thermal fly height control power. This can be use to determine the relationship between signal amplitude and thermal fly height control power with thermal protrusion being affected only by the thermal fly height control element and not from thermal heating of the near field transducer or write element. Then, thermal fly height control can be adjusted to achieve the desired signal amplitude for recording with the near field transducer and write element operating at a thermal steady state.

Abstract: Embodiments disclosed herein generally relate to a method for monitoring optical power in a HAMR device. In one embodiment, the method includes enhancing a thermal sensor bandwidth through advanced electrical detection techniques. The advanced electrical detection techniques include obtaining calibration waveform data for a thermal sensor by calibrating the thermal sensor, obtaining real-time waveform data for the thermal sensor that may deviate from the calibration waveform data, updating the calibration waveform data to include the real-time waveform data, repeating obtaining real-time waveform data and updating the calibration waveform data during writing operations. By updating the calibration waveform data, the bandwidth of the thermal sensor is determined by a fixed sampling time interval, and the thermal sensor rise time to steady state would not be a limitation to its response time.

Abstract: The present disclosure generally relates a method for removing a smear from a write head in a HAMR system. The smear can be removed by sufficiently heating the smear in an oxidative atmosphere to oxidize the smear. The material buildup that forms the smear has carbon, that when oxidized, is a gaseous product that leaves the write head with a reduced and/or eliminated smear. The heating occurs when the head is disposed in the parking location on the ramp remote from the magnetic media. Heating is possible using the same heat source for the HAMR head that is used to write data to the magnetic media.

Abstract: Described herein is a magnetic storage device that includes a magnetic disk and an arm rotatably movable relative to the magnetic disk. The magnetic storage device also includes a head actuator that is co-movable with the arm. The head actuator includes at least one piezo-electric element and at least one electronic communication signal line. Additionally, the magnetic storage device includes a read-write head coupled to the head actuator. The head actuator is operable to move the read-write head relative to the arm responsive to a first electronic signal received from the at least one electronic communication signal line. The magnetic storage device further includes a sensor module that is configured to determine whether the read-write head has touched down against the magnetic disk based on, at least partially, a second electronic signal received from the head actuator via the at least one electronic communication signal line.

Abstract: A procedure for accurately determining thermal flying height control (TFC) touchdown power associated with a head-disk interface (HDI) in a hard disk drive (HDD) involves dithering the spacing corresponding to the HDI by applying an oscillating signal. The touchdown power with the HDI dithering applied is determined and, based on that and the dithering amplitude, the touchdown power without dithering applied, as well as the back-off power, is determinable.

Abstract: Embodiments disclosed herein generally relate to contact at the disk by the recording head in a hard disk drive. In one embodiment, a direct current is applied to an element in a HAMR head. An alternating current is then applied to the element over top of the direct current to cause the HAMR head to dither. By monitoring the head signal at the dither frequency, a touchdown or contact of a NFT on a disk may be detected based upon variations in the produced signal.

Abstract: Embodiments disclosed herein generally relate to contact at the disk by the recording head in a hard disk drive. In one embodiment, a direct current is applied to an element in a HAMR head. An alternating current is then applied to the element over top of the direct current to cause the HAMR head to dither. By monitoring the head signal at the dither frequency, a touchdown or contact of a NFT on a disk may be detected based upon variations in the produced signal.

Abstract: A method, apparatus, and system are provided for implementing dual partially independent flyheight control (TFC) for hard disk drives (HDDs). A dual thermal flyheight control (TFC) includes a series connected first heater resistor and a second heater resistor connected between a pair of wires. A capacitor is connected in parallel with the first heater resistor providing a frequency dependent shunt to the parallel connected first heater resistor. TFC electrical bias signals are applied to the first heater resistor and second heater resistor carried by the pair of wires. For example, the TFC electrical bias signals include high frequency electrical signals including a frequency range between 1 MHz and 100 MHz having a set amplitude in a voltage range between 0 and 7 Volts, and/or DC current signal.

Abstract: A method, apparatus, and system are provided for implementing in-situ monitoring of head overcoat burnishing and early detection of head failure in a hard disk drive (HDD). A voltage is applied across a slider-disk interface between the slider body and the disk. Realtime monitoring of electrical current flowing across the slider-disk interface is performed for determining an amount of burnishing of the slider.

Abstract: A method, apparatus, and system are provided for implementing dual partially independent flyheight control (TFC) for hard disk drives (HDDs). A dual thermal flyheight control (TFC) includes a series connected first heater resistor and a second heater resistor connected between a pair of wires. A capacitor is connected in parallel with the first heater resistor providing a frequency dependent shunt to the parallel connected first heater resistor. TFC electrical bias signals are applied to the first heater resistor and second heater resistor carried by the pair of wires. For example, the TFC electrical bias signals include high frequency electrical signals including a frequency range between 1 MHz and 100 MHz having a set amplitude in a voltage range between 0 and 7 Volts, and/or DC current signal.

Abstract: A method and apparatus for determining the wear on a hard disk drive. Specifically, determining the overcoat wear of a head and/or disk during operation. In one embodiment, the magnetic head is disposed adjacent to the disk. A slider voltage is applied between a disk having a first overcoat and a head having a second overcoat as the disk is spinning By monitoring in real time a change in both touchdown power and a change in an interfacial current at a head disk interface, an electrochemical oxidation of the first overcoat can be determined. Additionally, by changing the polarity of the slider voltage, an electrochemical oxidation of the second overcoat can be determined. Finally, by measuring a passivation current produced between the head and the disk, the precise location of a touchdown event can be determined.

Abstract: A procedure for accurately determining thermal flying height control (TFC) touchdown power associated with a head-disk interface (HDI) in a hard disk drive (HDD) involves dithering the spacing corresponding to the HDI by applying an oscillating signal. The touchdown power with the HDI dithering applied is determined and, based on that and the dithering amplitude, the touchdown power without dithering applied, as well as the back-off power, is determinable.

Abstract: A method for annealing a metal antenna of a near field optical transducer of a magnetic write element without inadvertently heat damaging the read element. A heating element is placed within a write head build in a cerf region outside of the active area of the read and write heads. A layer of thermally conductive, electrically insulating material is formed over the heating element to separate the heating element from the antenna. The thermally conductive, electrically insulating layer is preferably in contact with the antenna. A current can be applied to the heating element to heat the antenna to a temperature that is at or above the operating temperature of the optical transducer. After annealing, the heater element can be removed by the lapping process that is used to define the media facing surface of the head.