Abstract: A magnetic head includes a dielectric waveguide to propagate propagation light; a metal waveguide facing the dielectric waveguide, coupling to the propagation light propagating through the dielectric waveguide in a surface plasmon mode, generating first surface plasmon with larger wavenumber than that of the propagation light, and propagating the first surface plasmon; a near-field light generating element facing the metal waveguide and extending to ABS, coupling to the first surface plasmon propagating on the metal waveguide in a surface plasmon mode, generating second surface plasmon with wavenumber larger than that of the first surface plasmon, propagating the second surface plasmon to an end part on the ABS side, and generating near-field light at the end part on the ABS side; and a recording magnetic pole provided in the vicinity of the near-field light generating element and having an end part positioned on the ABS.

Abstract: A method of manufacturing a thermally-assisted magnetic recording head includes: providing a light source unit including a light source; providing a substrate having a thermally-assisted magnetic recording head section thereon, the thermally-assisted magnetic recording head section including a magnetic pole, a plasmon generator, and an optical waveguide; inserting a metal between the light source unit and the substrate, and thus allowing the metal to be melted; and performing alignment between the light source unit and the thermally-assisted magnetic recording head section under application of pressure in a direction that allows the light source unit and the substrate to approach each other, while maintaining the metal melted.

Abstract: A thermally-assisted magnetic recording head is provided, in which the light-source output can be adjusted according to its variation by environmental influences and over time. The head comprises: a light source; a write head element provided in a element-integration surface; an optical system provided in the element-integration surface and configured to guide a light emitted from the light source to the vicinity of one end of the write head element; and a light detector for monitoring the light-source output, provided in the element-integration surface and comprising a light-receiving surface covering an area directly above at least a portion of the optical system. This light detector with such a light-receiving surface can detect a leakage light emitted from the optical system as a monitoring light. Therefore, feedback adjustment of the light-source output can be realized to stabilize the intensity of light for thermal-assist applied to a magnetic recording medium.

Abstract: A light source unit includes a light source and a photodetector. The light source has an emission part for emitting light. The photodetector has a light receiving surface for receiving the light emitted from the emission part, and detects the light. The light source unit further includes a grating made of metal and disposed to extend along the light receiving surface. The grating includes a plurality of line-shaped portions that each extend in a direction intersecting the direction of travel of the light and that are located at positions different from each other along the direction of travel of the light.

Abstract: A method for manufacturing a thermally-assisted magnetic recording head is provided, in which joined are: a light source unit that includes a light source having a surface including a light-emission center on the joining surface side of a unit substrate; and a slider that includes an optical system having a light-receiving end surface reaching a back surface opposite to the opposed-to-medium surface. This method utilizes “semi-active alignment” that uses an alignment light, and comprises steps of: causing a light to enter the light source from a surface opposite to the light-emission center; detecting the light that has passed through the light source and is emitted from the light-emission center to align the light-emission center with the light-receiving end surface of the slider; and bonding the light source unit to the slider. This manufacturing method can achieve the alignment with a sufficiently high alignment accuracy in a short processing time.

Abstract: The thermally-assisted magnetic recording head includes: a magnetic pole; a waveguide allowing a transverse-electric (TE) wave oscillating in a cross-track direction to propagate toward an air bearing surface; and a plasmon generator having a tip portion near the air bearing surface, the tip portion being provided to overlap, in a down-track direction, with both the magnetic pole and the waveguide, and having a quadrangular cross-section substantially parallel to the air bearing surface.

Abstract: A method of manufacturing a thermally-assisted magnetic recording head includes the steps of: forming a preliminary head section that has a surface to be polished and includes a magnetic pole, a waveguide, and a preliminary plasmon generator; causing a volumetric expansion of the preliminary plasmon generator with heat by introducing light into the core of the waveguide of the preliminary head section; and polishing the surface to be polished of the preliminary head section into a medium facing surface. The preliminary plasmon generator has an end face located in the surface to be polished. In the step of polishing the surface to be polished, the surface to be polished is subjected to polishing with the preliminary plasmon generator expanded in volume, whereby the end face of the preliminary plasmon generator is polished into the front end face, and the preliminary plasmon generator thereby becomes the plasmon generator.

Abstract: Provided is a thermally-assisted magnetic recording head in which a slider including an optical system is joined with a light source unit. The light source unit comprises: a unit substrate including a joining surface joined with the slider and a source-installation surface adjacent to the joining surface; a light source provided in the source-installation surface and emits light for thermal assist; and a photodetector section formed inside the unit substrate, a light-receiving portion of the photodetector section for receiving light emitted from a rear light-emission center being located on the source-installation surface side. The light source unit includes the photodetector section that enables constant monitoring of light output from the light source. Accordingly, feedback adjustment of the light output can be accomplished.

Abstract: A thermally-assisted magnetic recording head of the present invention includes waveguide 2 that includes core 3 through which light from a laser beam source propagates and cladding 4 that surrounds the periphery of the core 3, magnetic pole 10 that generates magnetic flux toward magnetic recording medium 25, plasmon generator 16 that faces a part of the core 3 and extends to the ABS, that couples to propagation light that propagates through the core 3 in a surface plasmon mode, and that generates surface plasmon, near-field light generating part 16a that is an end part of the plasmon generator on the ABS side and that generates near-field light from the surface plasmon, heat generation element 20 that thermally expands the thermally-assisted magnetic recording head, and dielectric body 40 that covers at least a part of the plasmon generator positioned on the ABS.

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: A heat-assisted magnetic recording head includes a slider, and an edge-emitting laser diode that emits polarized light of TM mode. The laser diode is arranged so that its bottom surface faces the top surface of the slider. An electrode of the laser diode closer to the active layer is bonded to a conductive layer of the slider, whereby the laser diode is fixed to the slider. As viewed from above the laser diode, the bottom surface of the electrode of the laser diode includes a first area that a light propagation path of the laser diode overlies, and a second area other than the first area. The top surface of the conductive layer is in contact not with the first area but with the second area of the bottom surface of the electrode.

Abstract: A method of the invention for performing burn-in test includes assembling, on a fixture stand, a plurality of light source elements and a plurality of light detectors for monitoring a light output from a corresponding one of the plurality of light source elements; and electrifying the plurality of light source elements in a state where at least the plurality of light source elements and the plurality of light detectors are immersed in an insulation liquid. Thereby, it is realized to hold a stable temperature in a short period of time, to maintain a temperature that does not deviate from normal load conditions, and to perform a sorting test between defect parts and good part for light source unit chips without causing damage to the elements.

Abstract: A slider has a slider substrate, an electromagnetic transducer, a waveguide for receiving light from a surface on the side opposite from a medium-opposing surface and guiding the light to the medium-opposing surface side, and a device electrode electrically connected to the electromagnetic transducer. A light source unit includes a light source supporting substrate, a light source, and a lead extending from the slider side to the side opposite from the slider and having both end parts exposed at a surface of the light source unit. The device electrode of the slider is exposed at the surface of the slider on the side opposite from the medium-opposing surface without being covered with the light source unit. An end part on the slider side of the lead of the light source unit is soldered to the device electrode of the slider.

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: A hard disk drive includes a recording medium and a thermally assisted type magnetic head. The controller determines one output current of a photodiode as a first saturated output current, the one output current being defined where temperature measured by a temperature sensor is a first temperature and where signal-to-noise-ratio (SNR) of the reproducing signal current of the reproducing element is saturated with respect to an increase in output current of the photodiode, and another output current of the photodiode as a second saturated output current, the another output current being defined where temperature measured by the temperature sensor is a second temperature, which is different from the first temperature, and where SNR of the reproducing signal current of the reproducing element is saturated with respect to an increase in the output current of the photodiode.

Abstract: An optical waveguide of the present invention is an optical waveguide in order to directly introduce light beams emitted from a light emitting element. In a core that is a waveguide through which light propagates, a concave part is formed that is a depression in a light incident end surface that is one side where light enters. Therefore, an optical waveguide is realized that can obtain a large optical coupling efficiency is possible by the operation of phase alignment in the concave part.

Abstract: A thermally-assisted magnetic recording head enables even steeper magnetization reversal between adjacent magnetic domains of a magnetic recording medium and satisfies the demand for high SN ratio and high recording density. The 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 through which light for exciting surface plasmon propagates, and a plasmon generator that couples to the light in a surface plasmon mode. The plasmon generator has a plane part and a projection part, the pole has a projection part opposing surface that opposes the projection part, and the distance between the projection part opposing surface and the projection part is 10-40 nm.

Abstract: The thermally-assisted magnetic recording head includes: a magnetic pole; a waveguide propagating light in a first direction, the first direction intersecting with an air bearing surface; a plasmon generator having a base and a projection, the base having a surface, and the projection having a top, standing partially on the surface of the base and extending in the first direction. The plasmon generator has a first portion and a second portion, and the first portion and the second portion are provided in this order from the air bearing surface in a direction away from the air bearing surface. Herein, the top of the projection and the surface of the base in the first portion define a first step, and the top of the projection and the surface of the base in the second portion define a second step. The first step is larger than the second step.

Abstract: A thermally-assisted magnetic head includes a slider including an air bearing surface (ABS) and a waveguide with a core that extends from a light entering surface to the ABS, and a laser diode (LD) unit attached to the light entering surface. The LD unit faces the light entering surface, and a photo detector faces the ABS. A polarizer that only transmits light having a polarization component orthogonal to a polarization direction of linearly polarized laser light is disposed between the ABS and the photo detector. An LD of the LD unit is activated, and the linearly polarized laser light enters the core from the light entering surface. Light radiated from the ABS enters the polarizer, and an alignment of the slider and the LD unit is performed while the photo detector detects the light transmitted through the polarizer.

Abstract: A plasmon antenna of the present invention is used in a thermally assisted magnetic head that includes: a medium-facing surface set, parallel to an XY plane; a magnetic pole for writing, extending toward the medium-facing surface, and a plasmon antenna comprising a pair of small metal bodies irradiated with excitation light for near-field light generation propagating in a Z-axis direction. Respective corners of the small metal bodies are spaced apart opposite each other along a TE mode direction of the excitation light. A distance between the corners gives the shortest distance between the small metal bodies, and a distance from each corner to the leading end of the magnetic pole gives a shortest distance from the small metal bodies to the leading end.