Abstract: A computer-implemented method, according to one embodiment, includes, for a particular data read clock value, generating a series of symmetrical square wave signals, each having a frequency that is a different fraction of the data read clock frequency. Anti-aliasing filtering is performed on each of the symmetrical square wave signals using predefined anti-aliasing settings. The filtered symmetrical square wave signals are passed through a band pass filter, the band pass filter being set to pass a single harmonic frequency of each of the symmetrical square wave signals. An amplitude of each of the band pass filtered symmetrical square wave signals is measured. In response to the amplitudes of the symmetrical square wave signals being within a predefined range, the anti-aliasing settings are stored. In response to the amplitudes of the symmetrical square wave signals being outside the predefined range, the anti-aliasing settings are changed, and the method is repeated.

Abstract: A first tone is written at a first frequency to outer tracks that surround an inner track of a magnetic recording medium. A second tone is written at a second frequency different from the first frequency to the inner track. The first and second frequencies are both lower than a frequency of an AC erase signal. A crosstrack profile of the inner track is determined based on reading amplitude of the second frequency via the read/write head.

Abstract: This application includes systems and techniques relating to storage devices, such as a device including: a first read channel to process a first input signal obtained from a storage medium using a first read head; a second read channel to process a second input signal obtained from the storage medium using a second read head, which is offset from the first read head in each of two dimensions; a single digital timing loop configured to control interpolation of timing of sampling for first and second analog to digital converters in the first and second read channels; and a two dimensional equalizer coupled with output lines of the first and second read channels; the device being configured to account for a fractional timing difference between the first input signal and the second input signal, the fractional timing difference being a fractional amount of a single clock cycle of the device.

Abstract: In one general embodiment, an apparatus includes a plurality of read transducers arranged in an array, and a plurality of biasing circuits. Each biasing circuit is coupled to a unique one of the read transducers. Each biasing circuit is configured to selectively reverse a direction of a read current applied to the read transducer associated therewith.

Abstract: A near-field transducer includes first and second stacked base portions having a common outline shape. The second base portion is proximate alight delivery structure. A peg extends from the first base portion towards a media-facing surface. The peg includes a material that is more thermally robust than a plasmonic material of the base portion. The peg has a peg thickness that is less than a thickness of the first base portion. The first base portion has a first recess proximate the peg. The first recess separates the first base portion from the media-facing surface and exposes at least a top side of the peg.

Abstract: Devices having air bearing surfaces (ABS), the devices include a near field transducer (NFT) that includes a disc configured to convert photons incident thereon into plasmons; and a peg configured to couple plasmons coupled from the disc into an adjacent magnetic storage medium, wherein the disc includes a disc material and the peg includes a peg material, wherein the disc material is different from the peg material and wherein the disc material has a first real part of the permittivity and a peg material has a second real part of the permittivity and the second real part of the permittivity is not greater than the first real part of the permittivity.

Abstract: Systems and methods for forward corrupted track detection and by-pass are described. In one embodiment, a storage system comprising a storage controller performs a read operation for a target track of a shingled magnetic recording (SMR) disk drive and detects a read operation failure of the read operation for the target track. The storage controller also performs a boundary track read operation on one or more tracks including or adjacent to the target track and detect a forward corruption area based on the boundary track read operation. In another embodiment, a method is provided that includes detecting a read operation failure of a read operation for a track of a disk drive and performing a boundary track read operation on one or more tracks including or adjacent to the target track. The method also includes detecting a forward corruption area based on the boundary track read operation.

Abstract: According to one embodiment, a magnetic disk device includes a disk including a tracks including a servo region, a light irradiator configured to irradiate the disk with light and heat the disk with the light, a head including a write head configured to write data in a range irradiated and heated with the light, and a read head configured to read data from the tracks, a controller configured to write first data to be used for offset detection in a first region of the tracks, read the first data from the first region with reference to servo data in the servo region, detect an offset of the read head based on an amplitude of a first signal of the first data, and control a position of the read head based on the offset.

Abstract: A heat-assisted magnetic recording (HAMR) head includes a reader, a writer, a writer heater, a laser, and a near-field transducer (NFT). A processor is coupled to the head and configured to perform laser writeability calibration of the head. The processor is also configured to concurrently while performing the laser writeability calibration, correct for laser induced writer protrusion (LIWP) at a writer/NFT region of the head using writer clearance calculations based on reader clearance measurements.

Abstract: A method and apparatus for detecting tightness of a pick-up head, and a method and apparatus for controlling the moving of the pick-up head are disclosed. The method for detecting the tightness of the pick-up head includes moving the pick-up head to an inner area of the disc reading device when then disc reading device is powered on, moving the pick-up head to an outer area of the disc reading device within a predetermined time period, moving the pick-up head from the outer area of the disc reading device to the inner area at a constant speed by a first fixed force, and recording the moving duration for moving the pick-up head from the outer area of the disc reading device to the inner area at the constant speed.

Abstract: Method and apparatus adaptively adjusting power levels of a data transducer in a data storage device. In some embodiments, an initial power value is applied to a powered element of a transducer to write user data from a host device to a rotatable data recording medium. An exception condition is declared responsive to a measured parameter. The transducer is used to read data from an evaluation track using a range of different input power values for the powered element. A different, new power value is selected for the powered element responsive to an error rate associated with each of the range of different input power values, with the new power value being lower than the initial power value. Thereafter, the new power value is applied to the powered element during a subsequent writing of user data to the rotatable data recording medium.

Abstract: An apparatus and method involves a writer configured for heat-assisted magnetic recording of data to a magnetic storage medium. A controller is coupled to the writer. The controller and writer are configured to write data to a plurality of concentric bands of the medium each comprising a plurality of partially overlapping narrow data tracks and a wide track. The wide tracks of successive bands are positioned adjacent to one another with no intervening narrow data track therebetween.

Abstract: An apparatus includes a waveguide that has a core between the first and second cladding layers. A near-field transducer in the first cladding layer is configured to receive the energy from the waveguide and deliver the energy to a recording medium. A reflector in the second cladding layer is configured to reduce reflection of the energy from the recording medium back to an energy source.

Abstract: Devices having air bearing surfaces (ABS), the devices including a near field transducer (NFT) that includes a disc configured to convert photons incident thereon into plasmons; and a peg configured to couple plasmons coupled from the disc into an adjacent magnetic storage medium, wherein at least one of a portion of the peg, a portion of the disc, or a portion of both the peg and the disc include a multilayer structure including at least two layers including at least one layer of a first material and at least one layer of a second material, wherein the first material and the second material are not the same and wherein the first and the second materials independently include aluminum (Al), antimony (Sb), bismuth (Bi), boron (B), barium (Ba), calcium (Ca), cerium (Ce), chromium (Cr), cobalt (Co), copper (Cu), erbium (Er), gadolinium (Gd), gallium (Ga), germanium (Ge), gold (Au), hafnium (Hf), indium (In), iridium (Ir), iron (Fe), lanthanum (La), magnesium (Mg), manganese (Mn), molybdenum (Mo), nickel (Ni), ni

Abstract: An integrated circuit connectable to a signal transmission path of a storage device includes an impedance setting circuit including a plurality of switches, a detector configured to detect an input signal level, and a decoder. The decoder controls one or more switches of the impedance setting circuit based on the detected input signal level so as to match an impedance of the integrated circuit with an impedance of the signal transmission path.

Abstract: Determining quality metrics of a magnetic tape recording medium. A production module that includes a write element that writes magnetic transitions to the magnetic tape is substantially in constant physical engagement with the magnetic tape. A supplemental module that includes one or more read elements periodically physically engages the magnetic tape, and the read elements generate an electrical signal corresponding to transitions written to the magnetic recording medium by a write element. A computer receives information representative of the electrical signal and determines if a quality metric of the magnetic recording medium derived from the electrical signal is within a defined range. If the quality metric is not within the defined range, a defined action is performed by the computer.

Abstract: A thermal assisted magnetic recording head has a magnetic head slider and a light source unit that is fixed to the magnetic head slider. A first surface of the light source unit and a second surface of the magnetic head slider face each other via a gap. The light source unit includes a light source that emits laser light from an emission part that is positioned on the first surface and a photodetector that detects the laser light. The magnetic head slider includes a waveguide through which the laser light that is incident on an incident part positioned on the second surface propagates, near-field light generation means for generating near-field light on an air bearing surface, the near-field light being generated from the laser light that propagates through the waveguide, and a recording magnetic pole that is provided adjacent to the near-field light generation means and that has an end part positioned on the air bearing surface.

Abstract: A magnetic recording device includes a magnetic recording medium, a microwave assisted magnetic head having a main magnetic pole for generating a recording magnetic field, and a spin torque oscillator provided near the main magnetic pole for generating a microwave magnetic field, a recording current supply part for supplying a recording current to recording coils according to recording current waveform data, a drive current supply part for supplying a drive current to the spin torque oscillator, and a drive current control part for controlling supply of the drive current by the drive current supply part based on the data. Taking into consideration as an indicator whether a polarity reversal interval included in the data exceeds a threshold time, the drive current control part controls the drive current supply part so as not to substantially lower the quality of signals recorded on the magnetic recording medium.

Abstract: An apparatus comprises a waveguide having an input end that receives energy in a transverse electric (TE00) mode from an energy source along a substrate-parallel plane. The apparatus also includes a near-field transducer located proximate an output end of the waveguide that receives the energy in the TE00 mode. The output end of the waveguide is at an oblique angle to a cross-track line at an intersection of a media-facing surface and the substrate-parallel plane. The near-field transducer includes an enlarged portion at the oblique angle to the cross-track line.

Abstract: Implementations disclosed herein provide a method comprising comparing high-latency data sectors of a storage band, the high-latency data sectors having latency above a predetermined threshold, with target sectors for storing new data to determine one or more of the high-latency data sectors that may be skipped during retrieval of at-rest data from the storage band.