Abstract: A thermally-assisted magnetic recording head includes: a pole that generates a writing magnetic field from an end surface that forms a part of an air bearing surface that opposes a magnetic recording medium; a waveguide that propagates light to excite surface plasmon; and a plasmon generator that is provided between the pole and the waveguide and that generates near-field light from a near-field light generating end surface that forms a part of the air bearing surface by coupling with the light in a surface plasmon mode. The plasmon generator includes a flat plate part and a projection part that projects from the flat plate part to the waveguide side and is provided closer to a trailing side than the pole is.

Abstract: A head assembly including one or more transducer elements for controlling head-media spacing is disclosed. The assembly includes detection circuitry configured to receive an input detection signal responsive to the spacing between the head and the data storage media and provide an output measure indicative of the head-media spacing. The output signal is utilized by control circuitry to provide a control input to one of a plurality of transducer elements on the head to protrude a localized portion of the head to adjust head-media spacing.

Abstract: A method of manufacturing a thermally-assisted magnetic recording head includes: providing a light source unit including a laser diode; providing a slider having a thermally-assisted magnetic recording head section thereon, the thermally-assisted magnetic recording head section including a magnetic pole, an optical waveguide, and a plasmon generator, the magnetic pole and the optical waveguide both extending toward an air bearing surface, the plasmon generator being located between the magnetic pole and the optical waveguide; driving the laser diode to allow a light beam to be emitted therefrom, the light beam including both a TE polarization component and a TM polarization component; performing an alignment between the light source unit and the thermally-assisted magnetic recording head section, based on a light intensity distribution of the TE polarization component in the light beam which has been emitted from the laser diode and then passed through the optical waveguide; and bonding the light source unit

Abstract: An apparatus includes a slider including an air bearing surface and a waveguide configured to receive light from a light source, a sensor positioned to receive a portion of light emitted by the light source prior to the light exiting the slider at the air bearing surface, and a controller controlling the light source power in response to a characteristic of the sensor.

Abstract: A magnetic head includes a medium facing surface that faces a surface of a recording medium, a write head section, a contact sensor that detects contact of the medium facing surface with the surface of the recording medium, and a heat sink adjacent to the contact sensor. The write head section has a magnetic pole that produces a write magnetic field for writing data on the recording medium. The contact sensor and the heat sink have respective end faces located in the medium facing surface. The contact sensor varies in resistance in response to temperature variations, and is to be energized. The heat sink includes an intermediate layer made of a nonmagnetic metal material, and two ferromagnetic layers made of a metal-based magnetic material, the two ferromagnetic layers being disposed with the intermediate layer therebetween, and being antiferromagnetically exchange-coupled to each other via the intermediate layer.

Abstract: A thermally-assisted recording (TAR) disk drive that uses “shingled” recording and a rectangular waveguide as a “wide-area” heat source includes a controller that counts the number of writes to each annular band of data tracks. The wide-area heater generates a heat spot that extends across multiple tracks, so that each time an annular band is written, the data in tracks in adjacent bands are also heated. Because the bands are written independently, the number of passes of the heat spot and thereby the number of times the data tracks in a band are exposed to elevated temperatures without being re-written is related to the number of re-writes of the adjacent bands. The number of writes to each band is counted and when that count reaches a predetermined threshold value, one or more tracks in an adjacent band are re-written to avoid reaching an unacceptable level of magnetization decay in the tracks of the adjacent band.

Abstract: A plasmon generator positioned away from the substrate and extending to the air bearing surface (ABS) as facing a part of the waveguide. The plasmon generator has a propagation edge extending in a longitudinal direction. The propagation edge has an overlapping part overlapping the waveguide in the longitudinal direction, and a near field light generator positioned on the ABS and located in the vicinity of the edge part of the recording magnetic pole. The overlapping part of the propagation edge is coupled with the laser light propagating through the waveguide in a surface plasmon mode so that a surface plasmon is generated. The propagation edge propagates the surface plasmon generated in the overlapping part to the near field light generator. The magnetic recording element further has a grounding element electrically connecting the plasmon generator and the substrate.

Abstract: A near-field light generating element has a core that guides a laser light in a direction of a disk while reflecting the laser light, and a cladding that encapsulates the core in an inner portion, and lengths of a longitudinal direction and a transverse direction of an incident side end surface of the laser light in the core are formed so as to match the lengths of a long axis direction and a short axis direction of the laser light that is entered to the core.

Abstract: According to one embodiment, a magnetic head for recording magnetic data by changing the magnetization direction of a magnetic recording layer of a magnetic medium comprises a magnetic pole for generating a magnetic field to change the magnetization direction of the magnetic recording layer, and a facing electrode pair for generating an electromagnetic field and applying energy to the magnetic recording layer to assist the change of the magnetization direction of the magnetic recording layer caused by the magnetic field from the magnetic pole. Other embodiments are also presented.

Abstract: Disclosed are a method and system for distinguishing spatial and thermal defects on perpendicular media. The magnetic domains of the perpendicular media are oriented to have a first polarity, scanned using a read head, oriented to have a second polarity and scanned again. The signals from the read head are combined to produce output signals having improved signal to noise ratios from which the locations of spatial and thermal defects can be identified and distinguished.

Abstract: A hard disk drive includes a chassis which supports a “sealed” housing containing a data storage magnetic disk, and read/write heads and actuator. The housing also contains an erasure device which generates a magnetic or other field or emanation for erasing the disk, so that the erasing field or emanation need not penetrate the sealed housing to effectuate erasure. A backup power supply provides power to the erasing device so that erasure can occur even in the absence of external power. A bus- or network-actuated arrangement couples power to the erasure device so that many hard drives may be simultaneously erased.

Abstract: A thermally-assisted recording (TAR) disk drive that uses “shingled” recording and a rectangular waveguide as a “wide-area” heat source includes a controller that counts the number of writes to each annular band of data tracks. The wide-area heater generates a heat spot that extends across multiple tracks, so that each time an annular band is written, the data in tracks in adjacent bands are also heated. Because the bands are written independently, the number of passes of the heat spot and thereby the number of times the data tracks in a band are exposed to elevated temperatures without being re-written is related to the number of re-writes of the adjacent bands. The number of writes to each band is counted and when that count reaches a predetermined threshold value, one or more tracks in an adjacent band are re-written to avoid reaching an unacceptable level of magnetization decay in the tracks of the adjacent band.

Abstract: Embodiments of the present invention help to suppress the effects of thermal fluctuation in a thermally assisted magnetic field recording, and improve recording density. According to one embodiment, a recording area of a magnetic disk is heated and the full width at half maximum of an optical power distribution of a near field light generator is controlled to be 100 nm or less. Thereby, the cooling time of the magnetic disk is made 2 nm or less and the effects of thermal fluctuation are suppressed. Moreover, although an incomplete area of the magnetization reversal at the rear end of the magnetic domain is created with rapid cooling, by creating an overshoot at the rising end of the magnetic field waveform of the magnetic recording head, the incomplete area of the magnetization reversal can be overwritten, which is created at the rear end of the magnetic domain previously recorded by the overshoot magnetic field.

Abstract: A near-field light generator includes: a waveguide; a clad layer having a penetrating opening and disposed on the waveguide; a plasmon generator accommodated in the opening; and a dielectric film interposed between the plasmon generator and each of the waveguide and the clad layer. In a method of manufacturing the near-field light generator, an initial clad layer is initially formed on the waveguide, and then the initial clad layer is taper-etched by RIE to form a recess that does not reach the top surface of the waveguide. Subsequently, the recess is etched by wet etching until the top surface of the waveguide is exposed in part. Next, the dielectric film is formed in the opening, and the plasmon generator is formed on the dielectric film.

Abstract: In one embodiment, there is provided a head controller for controlling a head of a read/write device which reads/writes data from/into a recording medium. The head controller includes: a controller configured to adjust a gap between the head of the read/write device and a surface of the recording medium by increasing/decreasing a power supplied to a heater, wherein the heater is configured to heat and expand the read/write device; and an acquisition unit configured to acquire output differences of the read/write devices for two or more rotation speeds of the recording medium, wherein the controller is configured to increase or decrease the power supplied to the heater based on the output differences of the read/write device.

Abstract: High density-information storage is accomplished by the use of novel, near-field optical devices in combination with high-density storage media. The near-field optical devices are configured to focus light to nanoscale spot sizes and may employ negative index of refraction materials for focusing. The high-density storage media may include protein-based storage media, such as photochromic proteins, and high-coercivity magnetic storage media. Light energy provided the optical devices may enable exposed protein molecules to transition between stable molecular states that may be distinguished on the basis of their respective spectral maxima. Light energy provided by the optical device may also be used to heat localized regions of magnetic media to a selected temperature, effecting local changes in coercivity of the magnetic media.

Abstract: A head using heaters or actuators to control head media spacing is disclosed. In embodiments disclosed the heaters are selectively energized to control a close point of the head for read and/or write operations. As disclosed power is supplied to multiple heaters to generate heat induced protrusion data and the heat induced protrusion data is used to apply power to the multiple heaters for head media spacing control.

Abstract: Information storage devices using magnetic domain wall movement, methods of operating the same, and methods of manufacturing the same are provided. An information storage device includes a first magnetic layer, a heating unit and a magnetic field applying unit. The heating unit heats a first region of the first magnetic layer. The magnetic field applying unit applies a magnetic field to the first region to form a magnetic domain. A wall of the magnetic domain is moved by a current applied to the first magnetic layer.

Abstract: A system that is capable of monitoring tribological data, such as friction, in a data storage device. In accordance with various embodiments, a magnetoresistive head is separated from a rotating data storage media by an air bearing and attached to a slider that is adjusted through deformation controlled by a heating element. A measurement circuit concurrently monitors friction from the head and power applied to the heating element to determine an MR head clearance. The measurement circuit includes at least a phase filter that eliminates off-phase friction from contributing to the determination of the MR head clearance.

Abstract: A magnetic head for data recording having a pair of heating elements that self regulate in response to temperature to distribute heat for thermal actuation. The head includes a first heating element located adjacent to the read sensor and away from the writer, and a second heating element located adjacent to the writer. The first and second heating elements have different coefficients of thermal resistance that cause the heating of the second heating element to increase relative to that of the first heating element when the overall temperature increases or when power provided by a power source increases. There, thereby prevents the read sensor from extending too much and possibly contacting the disk.

Abstract: Provided is a head slider that can heat a recording medium with a simple structure. In the head slider (10), a hole portion (14h) having an opening in a medium facing surface (10a) facing a disk-shaped recording medium (2) is formed, and a heating element (32) that is heated by being energized and a reflection portion (43) for reflecting heat radiated from the heating element (32) toward the disk-shaped recording medium (2) are disposed in the hole portion (14h).

Abstract: A method of manufacturing a thermally-assisted magnetic recording head includes: providing bar including, arranged in a first direction, a plurality of thermally-assisted magnetic recording head sections each including a waveguide, and a plurality of light source units each including a substrate with a light source mounted on a first surface of the substrate; bonding a second surface of the substrate to the bar with a bonding layer while allowing a light emitting position of the light source to be in opposition to the waveguide and allowing the first surface to be parallel to the first direction; and separating the bar for each of the thermally-assisted magnetic recording head sections. The substrate is bonded to the bar by radiating each laser beam from a dead angle direction where the first surface on which the light source units are provided is hidden from view.

Abstract: A thermal-assisted magnetic recording (TAMR) system is described which generates laser-pulse signals from the write data line. Additionally, training signals for initial synchronization are fed to the preamp IC using the write data line during servo read cycle. This requires no increase in the number of wires going to read-write driver chip (R/W IC) (preamp). In embodiments of the invention the R/W IC also includes registers that are set using serial data from the system electronics to influence the characteristics of the drive signal to the laser.

Abstract: A microwave assisted magnetic recording writer is disclosed with an octagonal write pole having a top portion including a trailing edge that is self aligned to a spin transfer oscillator (STO). Leading and trailing edges are connected by two sidewalls each having three sections. A first section on each side is coplanar with the STO sidewalls and is connected to a sloped second section at a first corner. Each second section is connected to a third section at a second corner where the distance between second corners is greater than the distance between first corners. A method of forming the writer begins with a trapezoidal shaped write pole in an insulation layer. Two ion beam etch (IBE) steps are used to shape top and middle portions of the write pole and narrow the pole width to <50 nm without breakage. Finally, a trailing shield is formed on the STO.

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: Various embodiments of the present invention provide systems and methods for data writing. As an example, a heat assisted data write circuit is discussed that includes a heat write output, a magnetic write output, and a variable phase shift circuit operable to modify a relative phase of the heat write output to the magnetic write output.

Abstract: A gap between a main pole and auxiliary pole composing a thin film magnetic head having a microwave assisted function of the present invention is filled with a nonmagnetic dielectric layer to embed a microwave radiator. The nonmagnetic dielectric layer has an inclined surface at a end on a side of an opposing medium surface by which the microwave radiated from the microwave radiator to be bent toward the main pole, whereby the microwave magnetic field generated from the microwave generator can be gathered immediately below the main pole, further improving the microwave assisted effect.

Abstract: The thermally assisted magnetic head comprises a medium-opposing surface; a magnetic recording device whose distance from a main magnetic pole to a medium is set longer than a distance from the medium-opposing surface to the medium; a first core for receiving light; and a second core positioned between a first light exit surface of the first core and the medium-opposing surface, having a second light exit surface on the medium side; while a distance between positions where an optical intensity distribution center within the first light exit surface and a center of the main magnetic pole are orthographically projected onto a reference plane including the second light exit surface is greater than a distance between an optical intensity distribution center within the second light exit surface and the position where the center of the leading end of the main magnetic pole is orthographically projected onto the reference plane.

Abstract: A curved waveguide is a curved waveguide that propagates laser light entering from the laser diode as propagating light.

Abstract: A thermally actuated head for magnetic head for magnetic data recording having a contact sensor for detecting contact between the head and a magnetic disk. The contact sensor includes a thermal sensor film and first and second leads, wherein the leads extend at least as far from the ABS as the thermal sensor film. More preferably the leads extend slightly further from the ABS than the sensor film so that contact between the magnetic disk and the contact sensor occurs at the leads rather than at the sensor film. The sensor film can be constructed of NiFe, preferably having 30-70 atomic percent Ni or more preferably 40-60 atomic percent Ni or most preferably 40-50 atomic percent Ni. The leads are preferably constructed of one or more of Ru, Rh or Ta or an alloy whose primary constituents are Ru, Rh or Ta.

Abstract: A magneto-optical transducer including a magnetic layer on a transparent, non-magnetic substrate is used to characterize the performance of a write head based on optically detected magnetization in the magnetic layer. The write head sample is held in contact with or near the magnetic layer, which is illuminated through the substrate with linearly polarized light. Magnetization in the write head produces a magnetization in the magnetic layer, which alters the polarization state in reflected light. The reflected light is analyzed and the intensity detected using an optical detector, such as one or more photo-detectors or a camera. The performance of the write head can then be characterized using the detected intensity.

Abstract: A magnetic media for heat assisted magnetic data recording. The magnetic media includes a thermal insulation layer structure formed near the substrate of the media provide more efficient heating of the write layer by allowing less heat dissipation to the substrate. The thermal insulation layer structure can be one or more layers of an oxide such as SiO2 and one or more layers of a material such as NiTa. Increasing the number of oxide layers and NiTa layers increases the thermal insulation of the thermal insulation layer structure thereby further increasing the efficiency of the heat assisted writing.

Abstract: A microwave oscillation element of the present invention includes a lamination main part in which an oscillating layer that is a magnetization free layer and that generates a high frequency electromagnetic field by an excitation of a spin wave, a nonmagnetic intermediate layer, a polarizer layer, and a reference layer that is to be a base magnetic layer of a spin transfer due to application of current are layered in this order. The oscillating layer is made of CoIr, the polarizer layer is configured of CoCr or CoRu; and the nonmagnetic intermediate layer is configured of Cr or Ru. As a result, the efficiency of the spin injection is improved and the microwave oscillation element where the oscillation efficiency is excellent can be realized.

Abstract: An apparatus and associated method is presently disclosed for a control circuitry capable of managing a heat source used in data storage applications. Various embodiments of the present invention are generally directed to a heat source directed at a data storage medium with a synchronization signal and a serial interface that are each selectively activated via a demultiplexed write gate signal. The selective activation allows for pulsed operation of the heat source resulting in reduced duty cycle and temperature during a write operation.

Abstract: An object is to provide a magnetic recording method that demonstrates an additional high assistance effect to magnetic recording by applying an alternate current magnetic field in the in-plane direction to a magnetic recording medium having a large coercive force, and a method of the present invention for magnetic recording using a magnetic recording head to a recording layer of a magnetic recording medium arranged to oppose the magnetic recording head, the magnetic recording head including a main pole, an auxiliary pole, a main coil for generating a perpendicular recording magnetic field to the main pole, and either a sub-coil for generating an in-plane alternate current magnetic field of a microwave band to the main pole or a microwave radiator that is arranged in vicinity of the main pole and that radiates microwaves, the method including: a step for modulating an amplitude of the in-plane alternate current magnetic field by modulating an amplitude of microwave alternating current that is applied to either

Abstract: A thermally-assisted magnetic recording method includes first and second steps. The first step applies heat to part of a hard disk medium and forms a moving high-temperature region in a magnetic recording layer of the hard disk medium. The high-temperature region is higher in temperature than a region therearound and has a temperature equal to or higher than the maximum coercivity vanishing temperature of a plurality of magnetic grains contained in the magnetic recording layer. At least one magnetic grain that is adjacent to the rear end of the high-temperature region in the direction of movement of the high-temperature region has a coercivity of a value other than 0. The second step applies a write magnetic field to the hard disk medium such that the write magnetic field applied to the at least one magnetic grain adjacent to the rear end of the high-temperature region is 3 kOe or smaller in magnitude.

Abstract: An apparatus includes a recording media including a substrate, a plurality of tracks of magnetic material on the substrate, and a non-magnetic material between the tracks; a recording head having an air bearing surface positioned adjacent to the recording media, and including a magnetic pole, an optical transducer, and a near-field transducer, wherein the near-field transducer directs electromagnetic radiation onto tracks to heat portions of the tracks and a magnetic field from the magnetic pole is used to create magnetic transitions in the heated portions of the tracks; and a plasmonic material positioned adjacent to the magnetic material to increase coupling between the electromagnetic radiation and the magnetic material.

Abstract: One purpose of the invention according to one embodiment is to provide a magnetic recording apparatus of high recording density in which magnetization transition curvature amount of a recording pattern is small. In one embodiment, the center of a heating area is arranged at a track edge side of a recording pattern as compared with the width-direction center position of a main magnetic pole of a recording head, and a recording magnetic field is applied while a medium is locally heated at the time of signal recording. A switching magnetic field of the medium is locally reduced by heating, so that a line where the switching magnetic field of the medium is equal to the recording magnetic field from the head approaches the heating center position, and a desired recording pattern in which the transition curvature amount is reduced can be realized. Other systems and methods are also presented.

Abstract: A magnetic device that includes a write pole having a write pole tip; a read pole having a read pole tip; an optical near field transducer; and a contact pad. The contact pad includes Ni100-aXa, wherein X is chosen from Ru, Re, Zr, Cr, and Cu; and a is the atomic percent of the element X, and can range from about 20 to about 90. The optical near field transducer is positioned between the read pole and the write pole and the contact pad is positioned adjacent the write pole opposite the optical near field transducer.

Abstract: A method of detecting a contact between a transducing head and a storage medium is provided. The method applies an input signal, having a select power level and known frequency, to an actuator for actuating the head. An output signal is obtained in response to the input signal. At least one signal component is extracted from the output signal at the same or a harmonic of the same known frequency as the input signal applied to the actuator. Whether the at least one extracted signal component indicates a contact between the head and the medium is determined. The power level of the applied wave pattern is increased incrementally until the extracted signal component indicates a contact between the head and the storage medium.

Abstract: A near-field light generating device includes a substrate, a semiconductor laser device, a light absorbing device, and a near-field light generator. The semiconductor laser device is formed on the substrate and emits the laser light polarized in a first direction. The light absorbing device is formed on the substrate to be close to a light emission part of the semiconductor laser device and absorbs light polarized in a second direction orthogonal to the first direction. The near-field light generator is formed on the substrate to be close to a light emission part of the light absorbing device.

Abstract: A method for manufacturing a thermally-assisted magnetic recording head is provided, in which a light source unit including a light source and a slider including an optical system are bonded. A unit substrate is made of a material transmitting light having a predetermined wavelength, and a unit adhesion material layer that contains Sn, Sn alloy, Pb alloy or Bi alloy is formed on the light source unit and/or the slider. The manufacturing method includes: aligning the light source unit and the slider in such a way that a light from the light source can enter the optical system and the unit adhesion material layer is sandwiched therebetween; and causing a light including the predetermined wavelength to enter the unit substrate to melt the unit adhesion material layer. The unit adhesion material layer melted by the light including the predetermined wavelength can ensure high alignment accuracy as well as higher bonding strength and less change with time.

Abstract: Provided is a head gimbal assembly (HGA) in which the electrodes for a thermally-assisted magnetic recording head comprising a light source, a photodetector and a magnetic head element, can be reliably electrically connected to wiring members by solder ball bonding (SBB). The HGA comprises a suspension comprising: a base; a first wiring member for the light source and the photodetector, provided on a side of one surface of the base; and a second wiring member for the magnetic head element, provided on the same surface side. The first and second wiring members protrude from the base toward the head to be fixed. As a result, the end portions (connection pads) of the first and second wiring members can be located close to electrodes for light-source and photodetector and electrodes for magnetic head element, respectively. This arrangement enables the end portions of the first and second wiring members to be reliably electrically connected to the electrodes by SBB.

Abstract: An apparatus includes a waveguide shaped to direct light to a focal point, and a near-field transducer positioned adjacent to the focal point, wherein the near-field transducer includes a dielectric component and a metallic component positioned adjacent to at least a portion of the dielectric component. An apparatus includes a waveguide shaped to direct light to a focal point, and a near-field transducer positioned adjacent to the focal point, wherein the near-field transducer includes a first metallic component, a first dielectric layer positioned adjacent to at least a portion of the first metallic component, and a second metallic component positioned adjacent to at least a portion of the first dielectric component.

Abstract: In a head for thermal assisted magnetic recording device, a semiconductor laser is mounted so that the total height of the head does not become larger and light power fluctuation due to wavelength fluctuation occurs less frequently. In addition, the rise in temperature of the mounted semiconductor laser is suppressed. A semiconductor laser is placed on a side surface which is different from surfaces on an inflow end side and a trailing side, of four side surfaces of a floating slider. An entrance of a waveguide is placed on the side surface of the floating slider, to thereby cause emitted light from the semiconductor laser to directly enter the waveguide. A curved line part or a reflective mirror is formed in the middle of the waveguide so that the light which has entered the waveguide travels toward an optical near-field generating element.

Abstract: Changes in the thermal boundary condition near a close point of an ABS to a media indicate proximity of the ABS with the media. Before contact, heat conduction from the ABS is primarily through convective and/or ballistic heat transfer to air between the ABS and the media. After contact, heat flux primarily flows from the ABS to the media through solid-solid conductive contact. Further, a light source within a HAMR transducer head may create additional thermal variations within the transducer head. These thermal variations create temperature variations within the transducer head. Two resistance temperature sensors on the transducer head at varying distances from the close point and/or light source measure these temperature variations. A temperature difference between the two resistance temperature sensors indicates proximity of the close point to the media and/or light output.

Abstract: An apparatus includes a non-metallic interlayer between a magnetic data storage layer and a heat sink layer, wherein interface thermal resistance between the interlayer and the heat sink layer is capable of reducing heat flow between the heat sink layer and the magnetic data storage layer. The apparatus may be configured as a thin film structure arranged for data storage. The apparatus may also include thermal resistor layer positioned between the interlayer and the heat sink layer.

Abstract: A TAMR (Thermal Assisted Magnetic Recording) write head uses the energy of optical-laser generated plasmons in a plasmon antenna to locally heat a magnetic recording medium and reduce its coercivity and magnetic anisotropy. To enable the TAMR head to operate most effectively, the maximum gradient of the magnetic recording field should be concentrated in the small region being heated. Typically this does not occur because the spot being heated by the antenna is offset from the position at which the magnetic pole concentrates its magnetic field. The present invention incorporates a magnetic core within a plasmon antenna, so the antenna effectively becomes an extension of the magnetic pole and produces a magnetic field whose maximum gradient overlaps the region being heated by edge plasmons being generated in a conducting layer surrounding the antenna's magnetic core.

Abstract: An aspect of the present invention relates to a glass substrate for a magnetic recording medium, which is comprised of glass with a glass transition temperature of equal to or greater than 600° C., an average coefficient of linear expansion at 100 to 300° C. of equal to or greater than 70×10?7/° C., a Young's modulus of equal to or greater than 81 GPa, a specific modulus of elasticity of equal to or greater than 30 MNm/kg, and a fracture toughness value of equal to or greater than 0.9 MPa·m1/2.

Abstract: A magnetic head includes a magnetic head slider; and a laser diode that is positioned on a surface of a side opposite to a substrate of the magnetic head slider and that generates laser light; the magnetic head slider including: a core through which the laser light emitted from the laser diode propagates as propagating light; a cladding that covers the core and that has a refractive index that is smaller than that of the core; a near field light generating means that generates near field light from the propagating light on an air bearing surface; and a main pole for recording that is disposed adjacent to the near field light generating means and of which an edge part is positioned on the air bearing surface.