Using a high sample rate dPES, together with pulsed heater and lock-in technique, to improve dPES SNR for contact detection between the head and media surface. Steps of powering a transducing head actuator with pulsed input signal at a select data track offset from a previously-written to data track of the storage medium, where the pulsed input signal has select amplitude and duty cycle to simulate a response signal, and further locking in an amplitude with respect to the heater frequency, can lead to a determination of level of heater power for initiating contact between the transducing head and the storage medium.

A slider of a heat-assisted recording head comprises electrical bond pads coupled to bias sources and a ground pad, an air bearing surface, and a waveguide configured to receive light from a laser source. A contact sensor proximate the air bearing surface is coupled between a first bond pad and a second bond pad. A bolometer is coupled to a reference thermal sensor. The bolometer is situated at a slider location that receives at least some of the light communicated along the waveguide. The reference thermal sensor is situated at a slider location unexposed to the light communicated along the waveguide. The bolometer and reference thermal sensor are coupled between the first and second bond pads and in parallel with the contact sensor. A ground connection is coupled to the ground pad and at a connection between the bolometer and the reference thermal sensor.

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. At least four different laser powers are applied to the laser and a fly height of the head over the disk is measured at each laser power. A lasing threshold power for the laser is detected based on the measured fly heights.

A data storage device is disclosed comprising a head actuated over a disk, wherein the head comprises a fly height actuator (FHA). A FHA control signal is applied to the FHA, wherein the FHA control signal comprises a DC component and an AC component. A fly height metric is measured representing a fly height of the head over the disk for different levels of the DC component. A modulation amplitude of the fly height metric is detected, and a minimum in the modulation amplitude of the fly height metric is detected.

A slider of a magnetic recording head comprises a media-facing surface, an upper surface opposing the media-facing surface, a leading edge, and a trailing edge. A plurality of electrical bond pads is disposed in a spaced-apart relationship on the trailing edge of the slider. An interconnect interposer is connected to the trailing edge of the slider. The interposer comprises a back side comprising a plurality of electrical contacts in contact with the plurality of bond pads on the trailing edge of the slider. The interposer also comprises a front side comprising a plurality of electrical interposer pads corresponding in number to the plurality of electrical contacts on the back side. The interposer further comprises a plurality of conductors each of which electrically couples one of the plurality of electrical contacts on the back side with one of the plurality of interposer pads on the front side.

A system, according to one embodiment, includes: a near field transducer, a return pole, a main pole, a waveguide adjacent the near field transducer, wherein the waveguide extends away from the near field transducer along a direction perpendicular to a media facing surface, at least one cladding layer adjacent to the waveguide, an underlayer positioned behind the near field transducer with respect to the media facing surface, the underlayer extending away from the near field transducer along the direction perpendicular to the media facing surface, and a fill material at least partially surrounding the underlayer, the waveguide and the at least one cladding layer. The underlayer has a lower coefficient of thermal expansion than the fill material. Other systems, and methods are described in additional embodiments,

A read/write head has a set of components that at least include: at least one clearance actuator; at least one read transducer configured to read from a magnetic recording medium; and at least one write transducer configured to write to the magnetic recording medium. A switch network is coupled to the set of components and configured to, in response to a control signal, couple a selected sub-combination of the components to a common set of signal lines. The coupling of the selected sub-combination facilitates operation in a selected mode of the read/write head.

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 storage device includes a disk, a head configured to carry out data writing and data reading with respect to the disk, and including a heater that generates heat to cause the head to thermally expand towards the disk, a non-volatile semiconductor memory, and a controller configured to set an amount of expansion of the head, based on data read from the disk during a predetermined period of time after the storage device has been turned on, and write data from a host in the disk or the non-volatile semiconductor memory during the predetermined period of time, based on the amount of expansion.

A magnetic head for perpendicular magnetic recording includes a read head unit, a write head unit disposed forward of the read head unit along the direction of travel of a recording medium, a heater that generates heat for causing the medium facing surface to protrude in part, an expansion layer that makes part of the medium facing surface protrude, and a sensor that detects contact of the part of the medium facing surface with the recording medium. The write head unit includes a main pole, a write shield, and a return path section. The return path section includes a yoke layer located backward of the main pole along the direction of travel of the recording medium, a first coupling part that couples the yoke layer and the write shield to each other, and a second coupling part that is located away from the medium facing surface and couples the yoke layer and the main pole to each other.