Abstract: The disclosure provides a self-biased magneto-optical non-reciprocal metasurface device. The device includes substrate layer and a sub-wavelength structure layer. The substrate layer is a material layer with a refractive index of 1 to 5 in a microwave frequency band. The sub-wavelength structure layer includes a plurality of square columnar elements arranged in a matrix period with equal period in row and column directions. The square columnar elements include magneto-optical material. The adjustment of phase and amplitude of a circularly polarized electromagnetic wave is achieved by changing the length, width and height of the square columnar elements, and thus the device attains a desired isolation and insertion loss at a center frequency f0. The parameters of the magneto-optical material are: coercivity Hc?1000 A/m; remanence Br?1 kGs; a voigt parameter of a permittivity tensor or permeability tensor in a working frequency band?0.01.

Abstract: An apparatus includes a substrate. A laser is formed on a non-self supporting structure and bonded to the substrate. A waveguide having a gap portion is deposited proximate the laser. The waveguide is configured to communicate light from the laser to a near-field transducer (NFT) that directs energy resulting from plasmonic excitation to a recording medium. An optical isolator is disposed over the gap portion.

Abstract: A system for conductive atomic force microscopy measurements includes a function generator that drives a light source as well as current provided to a sample, designed sample holder for local charge dynamics measurements and output circuitry that includes both a frequency response analysis as well as a bypass circuit analysis portion. Bypass circuit with external preamplifier helped to overcome the obstacles of commercially available AFM circuit bandwidth (e.g. 100 kHz) to see the local characteristics with high temporal resolution. By obtaining the data output of the frequency response analyzer and the bypass circuitry, local mobility map, local carrier lifetime and transport time map, local carrier density map, and a nanoscale impedance map can be made of complex solid state devices at high temporal and spatial resolutions.

Abstract: A heat-assisted magnetic recording medium includes a substrate, an underlayer, and a magnetic layer including an alloy having a L10 crystal structure and first and second layers, arranged in this order. Each of the first and second layers has a granular structure including C, SiO2, and BN at grain boundaries. Vol % of the grain boundaries in each of the first and second layers is 25 to 45 vol %. Vol % of C in the first layer is 5 to 22 vol %, and a volume ratio of SiO2 with respect to BN in each of the first and second layers is 0.25 to 3.5. Vol % of SiO2 in the second layer is greater than that of the first layer by 5 vol % or more. Vol % of BN in the second layer is smaller than that in the first layer by 2 vol % or more.

Abstract: A computer-implemented method according to one embodiment includes identifying an erasure code storage policy for an unified file and object storage system, determining a plurality of storage disks associated with the erasure code storage policy, retrieving disk health parameters for each of the plurality of storage disks, identifying a number of available outer partition storage blocks for each of the plurality of storage disks, and determining a number of erasure code fragments to be stored for a file within the unified file and object storage system before initiating an objectization process on the file, utilizing the disk health parameters for each of the plurality of storage disks and the number of available outer partition storage blocks for each of the plurality of storage disks.

Abstract: A method involves determining bit aspect ratios for interlaced tracks written to a magnetic recording medium. The interlaced tracks include top tracks that are written partially overlapping with bottom tracks. Isolated test tracks are written at first different bit aspect ratios to determine a top bit aspect ratio that achieves a first target areal density for the isolated test tracks. Test tracks are written at second different bit aspect ratios to determine a bottom bit aspect ratio that achieves a second target areal density for the test tracks. Top test tracks of the test tracks are written at the top bit aspect ratio. The top and bottom bit aspect ratios are selected to subsequently write partially-overlapping tracks on the magnetic recording medium.

Abstract: The magnetic tape device includes a magnetic tape; and a servo head, in which the servo head is a TMR head, the magnetic tape includes a servo pattern in the magnetic layer, a center line average surface roughness Ra measured regarding a surface of the magnetic layer is equal to or smaller than 2.0 nm, a logarithmic decrement acquired by a pendulum viscoelasticity test performed regarding the surface of the magnetic layer is equal to or smaller than 0.050, and a ratio (Sdc/Sac) of an average area Sdc of a magnetic cluster of the magnetic tape in a DC demagnetization state and an average area Sac of a magnetic cluster thereof in an AC demagnetization state measured with a magnetic force microscope is 0.80 to 1.30.

Abstract: A method involves determining bit aspect ratios for interlaced tracks written to a magnetic recording medium. The interlaced tracks include top tracks that are written partially overlapping and interlaced with bottom tracks. Isolated test tracks are written at first different bit aspect ratios to determine a top bit aspect ratio that achieves a first target areal density for the isolated test tracks. Interlaced test tracks are written at second different bit aspect ratios to determine a bottom bit aspect ratio that achieves a second target areal density for the interlaced test tracks. Top test tracks of the interlaced test tracks are written at the top bit aspect ratio. The top and bottom bit aspect ratios are selected to subsequently write interlaced tracks on the magnetic recording medium.

Abstract: A heat-assisted magnetic recording (HAMR) medium includes a substrate, a split heat-sink structure (SHSS) and a magnetic recording layer. The SHSS includes a first heat-sink layer disposed on the substrate, a heat-sink break layer (HSBL) disposed on the first heat-sink layer, and a second heat-sink layer disposed on the HSBL. The magnetic recording layer is disposed on the SHSS. The SHSS is configured to enable use of a reduced operating current of the laser while maintaining about the same write performance properties as a thermal barrier layer, heat-assisted magnetic recording (TBLHAMR) medium that includes a thermal barrier layer (TBL) and a heat-sink layer that is greater than about 20% thicker than the thickness of the SHSS. A HAMR data storage device that incorporates the HAMR medium within a HAMR disk, and a method for making the HAMR medium are also described.

Abstract: Embodiments are related to systems and methods for data processing, and more particularly to systems and methods for multi-dimensional signal equalization. In one case, a data processing system is discussed that includes: a first equalizer governed at least in part by a first coefficient; a second equalizer circuit governed at least in part by a second coefficient; and a constraint circuit operable to force a sum of at least the first coefficient and the second coefficient to equal a defined value.

Abstract: A method of testing a TAMH includes providing a slider body having a waveguide embedded therein with an incidence end extending toward a back surface of the slider body; providing a light source unit including a light source and a unit substrate; coating a bonding material layer on the back surface, under the bottom, or both on the back surface and under the bottom of the unit substrate; coating a localization material layer on the back surface; aligning the light source unit to the slider body; causing a light emitted from the light source and allowed to be incident on the incidence end to anneal the localization material layer to generate an annealing mark; removing the light source unit or the light source from the slider body; and measuring a position offset between the annealing mark and the incidence end. The method can evaluate alignment accuracy of a slider body and a light source unit in two dimensional directions.

Abstract: A system including a magnetic tape processing system that includes a read/write head to write to a top surface of a magnetic tape. The read/write head provides a write head field gradient of at least 40 Oersteds per nanometer at the top surface of the magnetic tape. The magnetic tape processing system and the read/write head provide a track density of greater than 8000 tracks per inch, a bit density of greater than 440 kilo-bits per inch, and an aspect ratio of less than 70.

Abstract: An audio signal processing apparatus does not drive a drive unit in a period during which an audio signal used for noise reduction processing is acquired, or does not stop a recording operation until the audio signal used for noise reduction processing is acquired.

Abstract: An operating device (1) for light-emitting device (5), where the operating device (1) has an interface circuit (2) and a drive circuit (3), where the interface circuit (2) generates an interface signal (21, 31, 41, 51) depending on a control signal (Vn, 10), and where the drive circuit (3) drives at least one light-emitting device (5) depending on the interface signal (21, 31, 41, 51). The control signal (Vn, 10) is an AC voltage control signal generated outside the operating device (1). The interface circuit (2) detects overshooting of an upper threshold value of only one of two half-waves of the control signal (Vn, 10), and the interface circuit (2) generates a first signal pulse (22, 55) in the interface signal (21, 31, 41, 51) for each detection of overshooting of an upper threshold value and identifies overshooting of a lower threshold value for the other half-wave.

Abstract: A laser diode device is affixed to a mounting face of a slider, opposite the air bearing surface. The laser includes a submount having an electrically conductive surface layer that is normal to the mounting face. The electrically conductive surface layer is a patterned metal layer that includes a lateral probing region and a laser mounting region to which a laser is soldered. The laser mounting region is connected to the lateral probing region by a bridge portion of the patterned metal layer. The laser mounting region is otherwise separated from the lateral probing region by a solder blocking gap in which the submount lacks the patterned metal layer, and which is adjacent to the laser. The solder blocking gap defines a solder blocking gap height normal to the mounting face that is in the range of ?rds to ?ths of a total height of the laser mounting region.

Abstract: An apparatus includes a near-field transducer at or near an air bearing surface of the apparatus. A write pole is disposed at or near the air bearing surface and proximate the near-field transducer, respectively. A thermal sensor is disposed at the air bearing surface and within a protrusion region of the air bearing surface defined relative to at least one of the near-field transducer and the write pole. The thermal sensor is configured to produce a signal indicative of a temperature at the protrusion region.

Abstract: The present invention relates to a plasmon generator, in which a surface plasmon is excited by application of light. The plasmon generator extends along one direction. The plasmon generator includes a first end surface that is positioned on one end in the one direction and at which near-field light is generated along with the excitation of the plasmon; and a second cross section that is substantially parallel to the first end surface and is away from the first end surface. The first end surface has a polygonal shape that does not have a substantially acute inner angle. The second cross section has an upper part that has a shape substantially the same as or similar to that of the first end surface and a flare shaped lower part that is connected to the upper part and has a width that increases as it is far from the upper part.

Abstract: A flex circuit including a dual sided interconnect structure to connect electrical components on a head or suspension assembly to head circuitry is described. The dual sided interconnect structure described has application for providing an electrical connection to one or more transducer elements on a slider and one or more elements of a heat assisted magnetic recording HAMR unit. In an illustrated embodiment, a flexible structure or insulating base layer includes one or more slider and heat assisted magnetic recording traces coupled to one or more slider or HAMR bond pads on an interconnect portion. As disclosed, the slider bond pads are on the obverse side of the flexible structure and the HAMR bond pads include a reverse side bonding surface to form reverse side bond pads to connect to one or more electrical or heating elements on the HAMR unit.

Abstract: An electrical lapping guide has a body with a thickness along a wafer axis, the body comprising a layer of conductive material having a resistivity. The conductive material layer comprises a first contact region and a second contact region, the first and second contact regions configured to electrically connect the electrical lapping guide to electrical leads. A lapping edge comprises an air-bearing plane axis perpendicular to a lapping axis, and a back edge opposite the lapping edge, the back edge comprising a plurality of notches.

Abstract: An apparatus comprises a write transducer comprising a write pole having a tip portion proximate a media-facing surface and a return pole spaced apart from the write pole in a downtrack direction. The apparatus further includes first and second heat sink portions. The first heat sink portion surrounds a first side of the tip portion that faces the return pole and extends outwards from the tip portion in a cross-track direction. The second heat sink portion comprises a first surface proximate the first heat sink portion and a second surface proximate the return pole and extends outwards in the cross-track direction further than the first heat sink portion.

Abstract: A system comprises a writer to form a plurality of color mits on a base material, wherein at least one of the color mits may represent computer-readable instructions comprising data other than pixel-image data. The plurality of color mits may include a first color mit and a second color mit, wherein the first color mit represents information data, and the second color mit represents that the first color mit contains a particular type of information data. The system also may include a reader to read colors of the plurality of color mits on the base material. The system may comprise a device to map at least one of the color mits to computer-readable instructions. The system may further comprise a processor configured to transmit signals using a colored light.

Abstract: A medium may be provided. The medium includes a servo layer, a data recording layer, and a heat sink layer disposed between the servo layer and the recording layer.

Abstract: An aspect of the present invention relates to glass for a magnetic recording medium substrate, which comprises essential components in the form of SiO2, Li2O, Na2O, and one or more alkaline earth metal oxides selected from the group consisting of MgO, CaO, SrO, and BaO wherein a molar ratio of a content of CaO to a combined content of MgO, CaO, SrO, and BaO (CaO/(MgO+CaO+SrO+BaO)) is equal to or less than 0.20, and which has a glass transition temperature of equal to or higher than 650° C.

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 near-field transducer at or near an air bearing surface of the apparatus. A write pole is disposed at or near the air bearing surface and proximate the near-field transducer, respectively. A thermal sensor is disposed at the air bearing surface and within a protrusion region of the air bearing surface defined relative to at least one of the near-field transducer and the write pole. The thermal sensor is configured to produce a signal indicative of a temperature at the protrusion region.

Abstract: Magnetic write heads for heat-assisted magnetic recording (HAMR) are disclosed that include a laser diode having a light emitting edge or surface mounted on a slider, an optical waveguide, and a printed bonding agent disposed in an air gap between the laser diode and the slider. The printed bonding agent can be applied by ink jet printing or aerosol jet printing. Also included is a method that includes attaching a laser diode to a slider of a magnetic write head and depositing a bonding agent into the air gap using a focused stream of bonding agent. A light-emitting edge or surface of the laser diode is adjacent to an optical waveguide. The light-emitting edge or surface of the laser diode and the optical input of the waveguide define an aligned direction and an air gap extends from the light-emitting edge or surface of the laser diode in a direction perpendicular to the aligned direction. The bonding agent can be applied by ink jet printing or aerosol jet printing.

Abstract: A disk drive is disclosed comprising a head actuated over a disk, wherein the head comprises a write element, a read element, and a laser operable to heat the disk while writing data to the disk. The disk is magnetized by writing a first test pattern to the disk using the write element and a first power applied to the laser. The magnetization of the first test pattern is destabilized by heating the disk using a second power applied to the laser, wherein the second power is less than the first power. After destabilizing the magnetization of the first test pattern, the first test pattern is read with the read element to generate a read signal, and the read signal is evaluated to detect a defect on the disk.

Abstract: A magnetic device including: a magnetic reader; a magnetic writer; and a variable overcoat, the variable overcoat positioned over at least the magnetic reader and writer, the variable overcoat having an overcoat layer, the overcoat layer having a substantially constant thickness and material; and at least one disparate overcoat portion, the disparate overcoat portion having a different thickness, a different material, or both, than the overcoat layer.

Abstract: Systems and methods related to writing data to a storage medium. In some cases, a heat assisted loopback circuit is used that includes: a read circuit, a magnetic write circuit, a heat write circuit, and a loopback circuit. The loopback circuit is operable to selectively couple a derivative of a heat output to a read output and to selectively couple a derivative of a write output to the read output.

Abstract: A method performed by a disk drive, comprising: receiving a plurality of signal samples over a channel in the disk drive; executing a forward pattern-dependent noise prediction (PDNP) operation on the plurality of the signal samples; generating, based on execution of the forward PDNP operation, a first detection of recorded data bits in the plurality of received signal samples; executing a backward PDNP operation on the plurality of the received signal samples; generating, based on execution of the backward PDNP operation, a second detection of recorded data bits in the plurality of received signal samples; comparing the first detection to the second detection; identifying, based on comparing, one or more erasures in the received plurality of signal samples; and generating one or more sequences of bits that promote correction of the one or more erasures.

Abstract: A magnetic data recording system employing a slider having a laser diode mounted to a side surface of the slider rather than to a back surface opposite the air bearing surface. The laser diode provides a light source for thermal assisted recording. Locating the laser diode at the side surface eliminates the possibility of contact between laser diodes of adjacent sliders and allows larger, more powerful laser diodes to be employed. In addition, placing the laser diode at the side allows a micro-actuator to be attached to the back side surface of the slider, thereby allowing both thermally assisted recording and micro-actuation to be used in the same recording system.

Abstract: A method of writing binary data comprising (i) heating a magnetic microstructure from an initial temperature to an above-ambient temperature that is not less than a transition temperature for the magnetic microstructure, which causes a phase transition interlayer of the magnetic microstructure to transition from an antiferromagnetic phase to a ferromagnetic phase; and (ii) reversing an orientation of magnetization of a magnetic storage layer of the magnetic microstructure with a magnetic field while the phase transition interlayer is in the ferromagnetic phase.

Abstract: An apparatus according to one embodiment includes a near field transducer comprising a conductive metal film; and an optical waveguide for illumination of the near field transducer, a light guiding core layer of the optical waveguide being spaced from the near field transducer by less than about 100 nanometers and greater than 0 nanometers, wherein a longitudinal axis of the optical waveguide is substantially perpendicular to an air bearing surface.

Abstract: An aspect of the present invention relates to glass for a magnetic recording medium substrate, which comprises essential components in the form of SiO2, Li2O, Na2O, and one or more alkaline earth metal oxides selected from the group consisting of MgO, CaO, SrO, and BaO wherein a molar ratio of a content of CaO to a combined content of MgO, CaO, SrO, and BaO (CaO/(MgO+CaO+SrO+BaO)) is equal to or less than 0.20, and which has a glass transition temperature of equal to or higher than 650° C.

Abstract: A thermally-assisted magnetic recording (TAMR) medium of the present invention includes: a magnetization direction arrangement layer on a substrate; and a magnetic recording layer on the magnetization direction arrangement layer, wherein the magnetization direction arrangement layer is made of at least one selected from a group consisting of Co, Zr, CoZr, CoTaZr, CoFeTaZrCr, CoNbZr, CoNiZr, FeCoZrBCu, NiFe, FeCo, FeAlN, (FeCo)N, FeAlSi, and FeTaC so that a spreading of the heating spot applied from the magnetic head for thermally-assisted recording to the film surface of the magnetic recording medium is suppressed, and that an SN is improved by arranging the magnetization direction of the perpendicularly written recording magnetization to become identical to a perpendicular direction, and realizing the higher recording density.

Abstract: A system comprises a writer to form a plurality of color mits on a base material, wherein at least one of the color mits may represent computer-readable instructions comprising data other than pixel-image data. The plurality of color mits may include a first color mit and a second color mit, wherein the first color mit represents information data, and the second color mit represents that the first color mit contains a particular type of information data. The system also may include a reader to read colors of the plurality of color mits on the base material. The system may comprise a device to map at least one of the color mits to computer-readable instructions. The system may further comprise a processor configured to transmit signals using a colored light.

Abstract: A display device includes a display portion, a cantilever, a rotating disc unit, a base, and two cables. The cantilever has an upper end connected with the display portion, allowing the display portion to rotate relative to the cantilever about a first axis. The rotating disc unit is connected with a bottom of the cantilever, allowing the cantilever to pivot relative to the rotating disc unit about a second axis, which is parallel with the first axis. The base is connected to the rotating disc unit in a manner allowing the same to rotate relative to the base about a third axis, which is vertical to the first and second axes. The cables extend downward from the display portion along the cantilever and are inserted into the rotating disc unit. The cables enter the base after being placed adjacent to one another within the rotating disc unit.

Abstract: A TAMR (thermal assisted magnetic recording) equipped DFH (dynamic flying height) type slider ABS design, when operating in a HDD (hard disk drive) produces exceptional low pressure/stiffness for improved touch down detection and back-off efficiency as well as wear and damage reduction due to the improved capabilities as well as reduction in heat transfers. The supplementation of the slider with multiple heaters, three herein, disposed about the write-head in the cross-track direction provides the slider with enhanced dynamic stability that would normally not be achievable with the exceptional low pressure/stiffness.

Abstract: An apparatus that includes a near field transducer, the near field transducer including silver (Ag) and at least one other element or compound, wherein the at least one other element or compound is selected from: copper (Cu), palladium (Pd), gold (Au), zirconium (Zr), zirconium oxide (ZrO), platinum (Pt), geranium (Ge), nickel (Ni), tungsten (W), cobalt (Co), rhodium (Rh), ruthenium (Ru), tantalum (Ta), chromium (Cr), aluminum (Al), vanadium (V), iridium (Ir), titanium (Ti), magnesium (Mg), iron (Fe), molybdenum (Mo), silicon (Si), or combinations thereof oxides of V, Zr, Mg, calcium (Ca), Al, Ti, Si, cesium (Ce), yttrium (Y), Ta, W or thorium (Th), Co, or combinations thereof; or nitrides of Ta, Al, Ti, Si, indium (In), Fe, Zr, Cu, W, boron (B), halfnium (Hf), or combinations thereof.

Abstract: A flex circuit including a multiple layer structure is disclosed. The multiple layered structure includes a first or top layer and a second or base layer. Top traces and bond pads are fabricated on the top or obverse layer and interlayer traces and bond pads are fabricated between the first and second layers to provide an electrical interconnect to electrical components on a head assembly. In an illustrated embodiment, the flex circuit includes portions including the first or base layer and the second or top layer and one or more reduced thickness portion including the first or base layer and not the second layer.

Abstract: A flex circuit including a dual sided interconnect structure to connect electrical components on a head or suspension assembly to head circuitry is described. The dual sided interconnect structure described has application for providing an electrical connection to one or more transducer elements on a slider and one or more elements of a heat assisted magnetic recording HAMR unit. In an illustrated embodiment, a flexible structure or insulating base layer includes one or more slider and heat assisted magnetic recording traces coupled to one or more slider or HAMR bond pads on an interconnect portion. As disclosed, the slider bond pads are on the obverse side of the flexible structure and the HAMR bond pads include a reverse side bonding surface to form reverse side bond pads to connect to one or more electrical or heating elements on the HAMR unit.

Abstract: Instead of using discontinuous step functions or pulses to drive a laser of a TAR enabled disk drive between on and off, a fixed modulation frequency may be used that alternates between a high and low laser power such that the radiation source is always delivering heat to the magnetic media when writing data to the magnetic disk. The magnetic field of the write pole may be synchronized to the modulation frequency of the radiation source to ensure that the radiation source heats the magnetic media proximate to the write pole above the grain freezing temperature when the Zeeman energy produced by the magnetic field of the write pole exceeds the thermal energy of the magnetic media.

Abstract: In accordance with one embodiment, a method is disclosed that comprises disposing an antireflection material in juxtaposition with a top surface of a slider. In accordance with another embodiment, a method is disclosed that comprises disposing an antireflective material between a facet edge of a laser and an incident surface of a waveguide. In yet another embodiment, an apparatus is disclosed that comprises a slider and an antireflection material in juxtaposition with a top surface of the slider.

Abstract: A heat assisted magnetic recording (HAMR) assembly includes a slider, a laser diode and solder connections between the laser diode and the slider. The solder connections mechanically and electrically attach the laser diode to the slider. Each solder connection has a total volume per unit area (i.e., height) of less than or equal to about 15 ?m. The solder connections have a first intermetallic zone adjacent to the laser diode, a second intermetallic zone adjacent to the slider, and a eutectic zone of eutectic material between the first and second intermetallic zones. The eutectic zone occupies greater than or equal to about 35% of the total volume per unit area of the solder connection.

Abstract: Magnetic write heads for heat-assisted magnetic recording (HAMR) are disclosed that include a laser diode having a light emitting edge or surface mounted on a slider, an optical waveguide, and a printed bonding agent disposed in an air gap between the laser diode and the slider. The printed bonding agent can be applied by ink jet printing or aerosol jet printing. Also included is a method that includes attaching a laser diode to a slider of a magnetic write head and depositing a bonding agent into the air gap using a focused stream of bonding agent. A light-emitting edge or surface of the laser diode is adjacent to an optical waveguide. The light-emitting edge or surface of the laser diode and the optical input of the waveguide define an aligned direction and an air gap extends from the light-emitting edge or surface of the laser diode in a direction perpendicular to the aligned direction. The bonding agent can be applied by ink jet printing or aerosol jet printing.

Abstract: Various embodiments of the present invention provide systems and methods for data writing. As an example, a heat assisted loopback circuit is discussed that includes: a read circuit, a magnetic write circuit, a heat write circuit, and a loopback circuit. The read circuit is operable to sense data from a storage medium, and to provide the sensed data as a read output. The magnetic write circuit is operable to provide a write output corresponding to an excitation signal of a write head. The heat write circuit is operable to provide a heat output corresponding to an excitation signal of a heat source. The loopback circuit is operable to selectively couple a derivative of the heat output to the read output and to selectively couple a derivative of the write output to the read output.

Abstract: A voice coil motor (VCM) includes a lens carrier physically connected to a magnetic device, an electromagnetic driving apparatus, constructed by a coil, a magnetic sensing element, a storage media and a controller. The magnetic sensing element detects a location of the lens carrier and outputs the location value relating to the location of the lens carrier via an amplifier. The storage media stores a gain value and an offset compensation value relating to the amplifier. The controller can make the lens carrier move between a top position and a bottom position in which the lens carrier can be moved within the voice coil motor. The lens carrier is moved using the coil interaction with a magnetic field of the magnetic device when current is applied to the coil.

Abstract: A manufacturing method of a light source chip for a thermally assisted head comprises steps of (a) providing a light source bar with a surface coating formed thereon; (b) forming several blind holes on the predetermined positions of the light source bar by etching, the blind hole having a top hollowed on the surface coating and a bottom hollowed on the light source bar, and the blind hole having a first biggest width at its top; (c) cutting the light source bar along every two adjacent blind holes by a cutting machine. The cutting machine has a cutting means with a second biggest width that is smaller than the first biggest width of the blind hole, thereby cutting down an individual light source chip without contacting the side edges of the blind hole.

Abstract: A microwave assisted magnetic recording head includes a recording magnetic pole unit that produces a recording field for writing to a perpendicular magnetic recording medium, and a high-frequency magnetic field oscillator that produces a high-frequency magnetic field. The recording magnetic pole unit includes a magnetic core with a write gap portion at which a main recording field component is concentrated, and the high-frequency magnetic field oscillator is disposed in the write gap.

Abstract: A thermally-assisted recording (TAR) disk has an improved insulating layer beneath the chemically-ordered FePt (or CoPt) alloy recording layer. The insulating layer is a solid substitution crystalline alloy MgXO, where the element X is selected from nickel (Ni) and cobalt (Co). The composition of the MgXO crystalline solid substitutional alloy is of the form (Mg(100-y)Xy)O where y is between 10 and 90, and more preferably between 20 and 80. An optional layer of crystalline “pure” MgO may be located between the MgXO layer and the FePt recording layer and in contact with the recording layer, or between an underlayer and the MgXO layer.