Abstract: A magnetic recording medium is provided that includes, in the order recited, a substrate; a first seed layer; a second seed layer containing ZnO; a third seed layer containing MgO; and a magnetic recording layer containing an ordered alloy. The first seed layer contains Ru and at least one material selected from the group consisting of oxides, carbides, and nitrides. Employing seed layers enables the magnetic recording medium to be a perpendicular magnetic recording medium by having the magnetic recording layer contain an ordered alloy suitable for perpendicular magnetic recording. Recording density is improved thereby while ensuring required thermal stability. Further, the invention achieves an increased thickness of the magnetic layer and a reduced grain size.

Abstract: A transformer includes a magnetic core, a first coil unit and a second coil unit. The first coil unit is disposed within the magnetic core and includes a laminated board having layers laminated therein and conductive patterns. Respective ones of the conductive patterns are disposed on the laminated layers. The second coil unit includes a conductive wire spaced apart from the conductive patterns of the laminated board by an insulating distance. The conductive wire includes a triple-insulated wire surrounded by three sheets of insulating paper to maintain the insulating distance from the conductive patterns.

Abstract: An apparatus includes a slider configured for heat-assisted magnetic recording. An input coupler of the slider is configured to-receive light produced by a light source. A waveguide of the slider comprises a waveguide core tapering from a first portion having a first cross sectional width to a second portion having a second cross sectional width along the light propagation direction. The second cross sectional width being smaller than the first cross sectional width, and the second portion having an output end. The waveguide includes at least one cladding layer comprising a metallic material. The at least one cladding layer surrounds at least the core. The at least one cladding layer is configured to sink heat away from the waveguide core. The waveguide is configured to provide a surface plasmon-enhanced near-field radiation pattern proximate the output end in response to the light received at the transducer region.

Abstract: According to one embodiment, a magnetic recording and reproducing device includes a magnetic recording medium, a magnetic head, and a controller. The controller implements a first operation and a second operation. The first operation is implemented in a first information recording interval including a first recording interval and a first non-recording interval. The second operation is implemented in a second information recording interval including a second recording interval and a second non-recording interval. The first operation includes in the first recording interval, generating a first signal magnetic field from the magnetic head, and in the first non-recording interval, generating a first non-signal magnetic field from the magnetic head. The second operation includes in the second recording interval, generating a second signal magnetic field from the magnetic head, and in the second non-recording interval, generating a second non-signal magnetic field from the magnetic head.

Abstract: A magnetic pulse recording method is disclosed wherein a magnetic field is turned off for a portion (tOFF) of a bit duration before or after total recording time is completed for each bit. Typical bit lengths of 10 nm to 50 nm must be less than the main pole down-track length, and total recording time (tREC) must be less than the bit duration such that bit duration equals (tREC+tOFF). In a random bit sequence, tREC may be maintained for each bit while tOFF increases as bit duration increases. The method applies to mobile hard disk drives (HDD) with 2.5 inch disks, and to nearline HDD with 3.5 inch disks where bit durations vary from 0.3 to 1.2 ns for recording velocities between 10 and 47 m/sec. The time required to turn off the field may be <10 picoseconds, and comprise a linear or non-linear waveform.

Abstract: A combination of a semiconductor member and a metal member is selected appropriately from a view point of increasing an enhancement factor of a near-field light. A device (1) has a semiconductor member (101) and a metal member (102), a near-field light is generated at the metal member when an energy is supplied to the semiconductor member, the metal member is made of an alloy including a first metal and a second metal, a condition of Rm1<Rs<Rm2 is satisfied, wherein a resonance wavelength of the first metal is Rm1, a resonance wavelength of the second metal is Rm2, and a resonance wavelength of the semiconductor member is Rs.

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: According to one embodiment, a magnetic disk drive records and reproduces referential data and measures a referential characteristic value in a state in which supply of a STO voltage is stopped, executes control of reducing a temperature set value of a heater at a recording operation, based on the referential characteristic value, records and reproduces corrected data and measuring a corrected characteristic value in a state of supplying the STO voltage with a polarity opposite to a polarity at a general operation, while varying the temperature set value at a recording operation, compares the referential characteristic value with the corrected characteristic value and obtaining a difference, and corrects the temperature set value based on the difference.

Abstract: 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.

Abstract: Before writing to a heat-assisted magnetic recording medium, a DC signal modulated with an AC signal is applied to a laser of a read/write head. A modulation level of an optical power sensor is measured, the optical power sensor being coupled to detect optical output of the laser in response to the modulated current. A target value of the DC signal that causes the modulation levels to reach a predetermined value between zero and a maximum value is determined and used to set a bias current for subsequent activation of the laser based.

Abstract: 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.

Abstract: A magnetic disk device includes a magnetic disk, a head slider and a control circuit. The head slider includes a read element, a write element, a first heater and a second heater. The first heater is arranged nearer to the read element than the write element. The second heater is arranged nearer to the write element than to the read element. The control circuit controls a ratio of powers to be supplied to the first heater and the second heater to adjust a first spacing between the read element and the magnetic disk and a second spacing between the write element and the magnetic disk.

Abstract: Methods of forming a NFT the methods including forming a hard mask positioned over at least a portion of the rod, the hard mask including at least one layer; patterning a resist mask over the hard mask, the resist mask having an edge positioned over at least a portion of the rod; etching a portion of the hard mask to expose a back edge of the rod and to form a back edge of the hard mask, wherein the back edge of the rod is equivalent to the back edge of the peg; and wherein a forward portion of the rod which is the portion of the rod forward of the back edge is covered by the hard mask; forming a disc mask including a void configured to form a disc of a NFT, the disc mask being formed over at least a portion of the hard mask so that the exposed back edge of the rod is within the void configured to form the disc; etching an area exposed in the void of the disc mask to remove both a rear portion of the rod and the surrounding dielectric up to the back edge of the hard mask edge; depositing a disc material in th

Abstract: A device and a method of forming a device are presented. A substrate is provided. The substrate includes circuit component formed on a substrate surface. Back end of line processing is performed to form an upper inter level dielectric (ILD) layer over the substrate. The upper ILD layer includes a plurality of ILD levels. A magnetic tunneling junction (MTJ) stack is formed in between adjacent ILD levels of the upper ILD layer. The MTJ stack comprises a free layer, a tunneling barrier layer and a fixed layer. The fixed layer includes a polarizer layer, a composite texture breaking layer which includes a ruthenium layer and a synthetic antiferromagnetic (SAF) layer.

Abstract: Embodiments described herein involve a method comprising generating a seek command in a heat-assisted magnetic recording (HAMR) device. A first current is supplied to a laser diode of the HAMR device in response to the seek command to preheat the laser diode. The first current is insufficient to cause erasure of data on media of the HAMR device. A second current that is greater than the first current is supplied to the laser diode for writing to a magnetic recording medium of the HAMR device after executing the seek command. Preheating the laser diode reduces a likelihood of a laser mode hop occurring while writing to the medium.

Abstract: A slider configured for heat-assisted magnetic recording has an upper surface, an opposing air bearing surface (ABS), and a body defined between the upper surface and the ABS. The slider comprises a write pole and a near-field transducer (NFT) at or near the ABS. An optical waveguide is configured to receive light from a laser source and comprises a first cladding layer, a second cladding layer, and a core between the first and second cladding layers. The core has a width, a length, and a longitudinal axis oriented along the length of the core. A bolometer is situated within the body of the slider at a location that receives at least some of the light communicated along the waveguide used during a writing operation. The bolometer is spaced apart from the core and comprises a longitudinal axis that is oriented substantially parallel to the longitudinal axis of the core.

Abstract: A method and apparatus for increasing storage capacity on magnetic media. A dual-layer magnetic recording apparatus receives, a write operation instruction, bit position and bit value where the bit position includes a media surface position and magnetic media layer identifier. The dual-layer magnetic recording apparatus accesses a dual-layer magnetic media where the dual-layer magnetic media includes a first magnetic media layer with a thermally controllable coercivity, a second magnetic media layer and a separation layer. The magnetic layer identifier is determined to associated with be the first magnetic media layer or the second magnetic media layer. When the magnetic layer identifier is the second magnetic media layer, the bit value is written based on magnetically charging the second magnetic media layer and when the magnetic layer identifier is the first magnetic media layer the bit value is written based on heating and magnetically charging the first magnetic media layer.

Abstract: An apparatus, according to one embodiment, comprises a near field transducer; an adhesion layer on a media facing side of the near field transducer, the adhesion layer comprising Ni and Cr; and a protective layer on a media facing side of the adhesion layer. Other apparatuses, systems and methods are described in additional embodiments.

Abstract: Provided herein is an apparatus including a head over-coat and a depleted region in the head over-coat. A media over-coat is deposited in the depleted region. A near field transducer is adjacent to the head over-coat, wherein the near field transducer combusts the deposited media over-coat.

Abstract: 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.

Abstract: A recording head includes a layer of plasmonic metal deposited on a surface of the recording head. One or more non-self-supporting layers of crystalline material are attached to the plasmonic metal, the one or more layers of crystalline materials configured to form an active region of a laser. A waveguide is configured to receive plasmons from the laser and direct the plasmons to a recording medium.

Abstract: A method of magnetization reversal, time stable ferrimagnetic material, a product and a domain comprising said material, a system for magnetization reversal, and information storage. Therein, a ferrimagnetic material is one in which magnetic moments of the atoms on different sublattices are opposed, as in antiferromagnetism; however, in ferrimagnetic materials, the opposing moments are unequal and a spontaneous magnetization remains.

Abstract: A head includes a head body having a medium facing surface, and a protective film covering the medium facing surface. The head body includes a main pole, a waveguide, a plasmon generator, and a main light-blocking section. The waveguide has an entrance end face and an exit end face. The plasmon generator has a near-field light generating surface. The medium facing surface includes a first region including neither of the exit end face and the near-field light generating surface, and a second region including the exit end face and the near-field light generating surface. The protective film includes a first portion covering the first region, and a second portion covering the second region. The main light-blocking section is located to intersect an imaginary straight line connecting the entrance end face and the first region.

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: Scanning mechanisms that have application in confocal imaging use electromagnetic actuation to move elements in an optical system. An objective lens mounted to a flexure comprising a magnetic material is actuated in the axial direction by an electromagnet coil. An optical path may pass through the coil. Scanning in transverse directions may be provided using magnetically actuated flexible beams which move the tip of an optical fiber or other pinhole in one or more transverse directions. Actuators may be actuated using driving currents that include an AC component and a DC bias component. The scanning mechanisms may be miniaturized and may be constructed to provide real-time imaging.

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: A recording head includes a near-field transducer located an oblique angle to a media-facing surface. The near-field transducer includes an enlarged portion and a peg extending from the enlarged portion towards the media-facing surface at a normal angle. An input waveguide of the recording head receives energy from an energy source, and an output waveguide delivers the energy to near-field transducer at the oblique angle. The output waveguide is oriented at the oblique angle. A bent waveguide with a polynomial spiral shape joins the input waveguide and the output waveguide.

Abstract: Methods of forming a NFT the methods including forming a hard mask positioned over at least a portion of the rod, the hard mask including at least one layer; patterning a resist mask over the hard mask, the resist mask having an edge positioned over at least a portion of the rod; etching a portion of the hard mask to expose a back edge of the rod and to form a back edge of the hard mask, wherein the back edge of the rod is equivalent to the back edge of the peg; and wherein a forward portion of the rod which is the portion of the rod forward of the back edge is covered by the hard mask; forming a disc mask including a void configured to form a disc of a NFT, the disc mask being formed over at least a portion of the hard mask so that the exposed back edge of the rod is within the void configured to form the disc; etching an area exposed in the void of the disc mask to remove both a rear portion of the rod and the surrounding dielectric up to the back edge of the hard mask edge; depositing a disc material in th

Abstract: A heat-assisted magnetic recording (HAMR) disk drive has a disk with at least two independent data layers (RL1 and RL2), each data layer storing an independent data stream. At a high laser power both RL1 and RL2 are heated to above their respective Curie temperatures and a first data stream is recorded in both RL1 and RL2. At a lower laser power only upper RL2 is heated to above its Curie temperature and a second data stream is recorded only in RL2. The data layers are separated by a nonmagnetic spacer layer (SL) that prevents lower RL1 from being heated to above its Curie temperature at low laser power. The first and second data streams are typically asynchronous. Recorded data is read back from both data streams simultaneously as a composite readback signal. A joint Viterbi detector detects the asynchronous data streams simultaneously from the composite readback signal.

Abstract: An apparatus includes a slider body of a disk drive. The slider body is electrically coupled to a plurality of end bond pads. A voltage applied to one more of the end bond pads sets a surface potential of the slider body.

Abstract: When a simple magnification optical system is used in reproduction of a recording medium in which a large number of minute modified regions are three-dimensionally formed inside solid matter, contrast is insufficient and interlayer crosstalk is increased, and therefore, it is impossible to take a sufficient S/N ratio. Provided is a recording medium in which at least one layer is configured by a set of two adjacent sub-layers, and dots on a sub-layer correspond to a recording data ‘1’ and dots on the other sub-layer correspond to ‘0’. These data are played back.

Abstract: A mechanism is provided for fabricating a thermally assisted magnetoresistive random access memory device. A bottom thermal barrier is formed on a bottom contact. A magnetic tunnel junction is formed on the bottom thermal barrier. The magnetic tunnel junction includes a top ferromagnetic layer formed on a tunnel barrier. The tunnel barrier is formed on a bottom ferromagnetic layer. A top thermal barrier is formed on the top ferromagnetic layer. A top contact is formed on the top thermal barrier. The top contact is reduced to a first diameter. The tunnel barrier and the bottom ferromagnetic layer each have a second diameter. The first diameter of the top contact is smaller than the second diameter.

Abstract: A relatively larger nominal track spacing associated with a first write head is determined and a relatively smaller nominal track spacing associated with a second write head is determined. The first and second write heads simultaneously write to respective different first and second surfaces of a heat-assisted recording medium. A laser write power for a selected one of the first write head and the second write head is changed to enable the first write head and the second write head to operate at an equivalent nominal track spacing.

Abstract: Acoustically assisted magnetic recording can be used in a hard disk drive or a solid state medium. In the described embodiments, otherwise unwriteable high-coercivity media are made amenable to recording by lowering their coercivity via strain induced by acoustic waves. The use of acoustic waves temporarily and locally reduces the magnetic field required to record information on a magnetic recording medium. The process makes use of the magnetostrictive property of a magnetic material by which the magnetic anisotropy of the material is changed by strain. The result of such a change is a reduction in the coercive field, i.e., the magnetic field required to reverse the magnetization direction. Because acoustic waves cause strain, the passage of an acoustic wave through a magnetic material can be used to reduce its coercive field.

Abstract: A crystal film with one or more nitrogen vacancy centers is placed in close proximity to a recording head. A magnetic field or heat produced by the recording head as well as excitation illumination and an excitation field is applied to the crystal film. The magnetic field produced by the recording head, the heat produced by a thermal device on the recording head, and/or the excitation field may be varied. A confocal microscope or wide-field microscope optically detects a decrease in a spin dependent photoluminescence in response to the magnetic field or heat, excitation field and excitation illumination caused by electron spin resonance (ESR) of the at least one nitrogen vacancy center to measure Optically Detected Spin Resonance (ODMR). A characteristic of the recording head is determined using the ODMR.

Abstract: An air-bearing surface of a slider is coated with a photoresist having a high optical absorbance at or near an operational wavelength of the slider. Light is directed at a target wavelength through an entry of a waveguide integrated into the slider. The light exiting the waveguide forms a feature through the photoresist, the feature proximate a near-field transducer of the slider. A sub-micron pattern is formed using the feature.

Abstract: A light source is configured to produce light, a waveguide is optically coupled to the light source and configured to direct the light to an intended focus location, and a slider is configured to use the light as an energy source for heating a region of a magnetic recording medium. A thermal sensor is situated on the slider at a location outside of a light path that includes the intended focus location. The thermal sensor is configured for sensing a short time constant change in temperature resulting from light source heating of the thermal sensor, wherein the sensed change in thermal sensor temperature is representative of optical intensity of the light delivered to the intended focus location.

Abstract: A microwave assisted magnetic recording system includes a write pole that generates a write magnetic field, an element that generates a radio frequency assist magnetic field, and a recording medium that moves relative to the write pole. The recording medium is exposed to the radio frequency assist magnetic field before it is exposed to the write magnetic field. One possible element that generates the radio frequency assist magnetic field is an assist wire placed perpendicular to the write pole. Alternatively, the assist wire can be placed parallel to the write pole so that its radio frequency assist magnetic field couples with the write pole, which in turn generates its own coupled radio frequency magnetic field along with the write magnetic field.

Abstract: An apparatus with a slider body, a laser diode, and an isolator element. The slider body has an optical pathway extending therealong. The laser diode is configured to emit light along the optical pathway. The isolator element is disposed in the optical pathway to reduce optical feedback along the optical pathway back to the laser diode. In some embodiments, the isolator element is disposed in the optical pathway between the laser diode and the slider body.

Abstract: The embodiments disclosed generally relate to an STO structure for a magnetic head. The STO structure has an FGL having a greater thickness than the SPL. The SPL may have multiple layers. In one embodiment, a MAMR head comprises a main pole; a trailing shield; and an STO coupled between the main pole and the trailing shield. The STO includes: a first magnetic layer having a first thickness; a non-magnetic spacer layer coupled to the first magnetic layer; and a second magnetic layer having a second thickness and coupled to the non-magnetic spacer layer, wherein the first thickness is greater than the second thickness, wherein a current is charged from the first magnetic layer to the second magnetic layer, and wherein a vertical magnetic anisotropy field of the second magnetic film is less than 0 kOe.

Abstract: A testing method of a magnetic head includes: applying a first magnetic field with a constant intensity in a first direction that is the same with that of the longitudinal bias field to the magnetic head, simultaneously applying a second magnetic field with variant intensities in a second direction traversing the air bearing surface, and measuring a first noise; applying a third magnetic field with a constant intensity in a third direction that is opposite to the first direction to the magnetic head, simultaneously applying the second magnetic field with variant intensities in the second direction, and measuring a second noise; and analyzing noise change between the first noise and the second noise. The invention can screen out defective magnetic heads that possess poor noise characteristic and unstable performance.

Abstract: A method fabricates a heat assisted magnetic recording (HAMR) transducer having an air-bearing surface (ABS) and that is optically coupled with a laser. The method includes providing a waveguide for directing light from the laser toward the ABS and providing a write pole having a pole tip with an ABS location facing the surface. The pole tip is in a down track direction from the waveguide. The method also includes providing at least one shield including a shield pedestal. The shield pedestal is in the down track direction from the pole tip. At least one protective pad is provided adjacent to the write pole and between the ABS location and the shield pedestal.

Abstract: An apparatus including a waveguide input coupler, a tapered branch waveguide, and a waveguide adaptor physically connected to the waveguide input coupler proximal end and to the branch waveguide proximal end. The waveguide input coupler includes a distal end having a distal end width and a proximal end having a proximal end width. The tapered branch waveguide includes a distal end having a distal end width and a proximal end having a proximal end width, the branch waveguide distal end width being greater than the branch waveguide proximal end width. The waveguide input coupler, the branch waveguide, and the waveguide adapter are configured to convert input light having a base transverse waveguide mode to output light having a higher-order waveguide mode.

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: A plasmon generator includes a first portion and a second portion that are adjacent in a first direction orthogonal to the direction of travel of light propagating through a core. The second portion includes a front end face located in a medium facing surface of a magnetic head. The core has a concave portion recessed from the top surface of the core. At least part of the first portion is received in the concave portion. The concave portion has a surface including an evanescent light generating portion. The first portion includes a plasmon exciting portion opposed to the evanescent light generating portion. The evanescent light generating portion is inclined relative to a first surface.

Abstract: Using a thermally assisted magnetic recording head, reference signals are recorded into a magnetic recording medium; reproduction signal intensity of the reference signals is measured in a state where the thermally assisted magnetic head has been moved in the track width direction from the track width center of the track where the reference signals are recorded; a mean signal output of each sector in the track where the reference signals are recorded is calculated from the measurement results of the reproduction signal intensity of the reference signals; and the recording characteristics of a thermally assisted magnetic head are evaluated based upon the mean signal output of the sectors.

Abstract: A heat-assisted magnetic recording (HAMR) medium having improved signal-to-noise ratio capabilities includes a high-temperature exchange break layer (EBL) inserted between magnetic recording layers, where the high-temperature exchange break layer material is capable of maintaining its chemical properties at temperatures exceeding 300° C. The high-temperature EBL may include a non-metallic compound including at least one of an oxide, a carbide, and a nitride.

Abstract: Embodiments disclosed herein generally relate to a HAMR head. The HAMR head includes a main pole, a waveguide and a NFT disposed between the main pole and the waveguide. The NFT includes an antenna, and the antenna is made of a compound that has a composition that varies based on the location within the antenna. In one embodiment, the antenna has a surface at a media facing surface (MFS) and the surface has an apex, and the composition of the compound varies from the apex in a direction away from the apex. The apex has the highest temperature during the operation of the HAMR head, and having a composition that is thermally stable at the apex helps achieve higher reliability.

Abstract: Embodiments disclosed herein generally relate to a HAMR device for use in a magnetic reading system. The HAMR device has a primary waveguide extending from a media facing surface to a surface opposite the media facing surface. In one embodiment, the HAMR head has a secondary waveguide having a first and second end positioned within the HAMR head. The secondary waveguide is positioned near the primary waveguide, and the first and second ends of the secondary waveguide are non-reflecting. A thermal sensor is coupled to the secondary waveguide, and responds only to optical power fluctuations in the primary waveguide. In another embodiment, the HAMR head has a second thermal sensor rather than a secondary waveguide. The first thermal sensor and the second thermal sensor are coupled together to act as one optical power sensor and are disposed on the primary waveguide.

Abstract: There is disclosed a hard disk drive and a method of controlling a flying height of a magnetic head of the hard disk drive. A method of controlling a flying height of the magnetic head in a hard disk drive according to an embodiment of the present invention may include (a) providing a FOD sensitivity through a FOD test; (b) reading a preamble signal of a servo pattern; (c) calculating a flying height of the magnetic head from the preamble signal; and (d) applying FOD power for adapting the flying height of the magnetic head to a target flying height of the magnetic head based on the calculated flying height of the magnetic head and the FOD sensitivity.