Abstract: There is provided a near-field-light (NFL) generating optical system in which the point where near-field (NF) light is generated can be provided sufficiently close to the end surface of a magnetic pole that generates write field. The optical system comprises: a waveguide through which a light for exciting surface plasmon propagates; and a NF-optical device configured to be coupled with the light in a surface plasmon mode. The NF-optical device comprises: a contact-to-waveguide surface having a contact to the waveguide; and a propagation edge provided on the side opposite to the contact-to-waveguide surface, extending to the NFL-generating end surface of the device, and configured to propagate thereon the surface plasmon excited by the light. In this optical system, the point, where NF-light is generated, of the NFL-generating end surface is reliably located on the side opposite to the waveguide.

Abstract: A thermally-assisted magnetic head that includes an air bearing surface facing a recording medium and that performs magnetic recording while heating the recording medium includes: a magnetic recording element including a pole of which one edge part is positioned on the air bearing surface and that generates magnetic flux traveling toward the magnetic recording medium; a waveguide configured with a core through which light propagates and a cladding, at least one part of which extends to the air bearing surface, surrounding the periphery of the core; a plasmon generator that faces a part of the core and that extends to the air bearing surface.

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.

Abstract: A thermally-assisted magnetic recording head includes a surface-emitting type light source for emitting substantially collimated beam, a first diffraction optical element for focusing the substantially collimated beam emitted from the surface-emitting type light source, a second diffraction optical element for collimating the light beam focused by the first diffraction optical element, a waveguide integrally formed with the second diffraction optical element and made of the material as that of second diffraction optical element, the light beam collimated by the second diffraction optical element being incident to the waveguide, an optical-path direction conversion element for converting a direction of an optical path of the incident light beam to a propagation direction of the waveguide, the propagation direction being toward an opposed-to-medium surface, and a magnetic pole for generating write field from its end face on the opposed-to-medium surface side.

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 waveguide is provided, in which the optical coupling efficiency to a light source is sufficiently high, and the light-emitting spot center is stably provided at the intended position. The waveguide comprises a multilayered structure in which refractive indexes of layers having a surface contact with each other are different from each other. The multilayered structure is divided into a plurality of groups, and the length from the light-receiving end surface to the light-emitting end surface of one group is different from that of the neighboring group, and the protruded light-emitting end surface of the first group defined as a group that has the largest length includes a center of the light-emitting spot. In this waveguide, the state in which the light-emitting spot center is positioned within the light-emitting end surface does not easily be changed, even when the light-receiving spot center within the light-receiving end surface is rather displaced.

Abstract: A plurality of laser diode units is tested in a bar state, each of the laser diode units in which a laser diode that includes a first electrode and a second electrode formed on surfaces facing each other and that is mounted on a mounting surface of a submount such that the first electrode faces the mounting surface of the submount.

Abstract: Provided is a method for performing a burn-in test on an object under test in which a plurality of electrodes are provided in positions at different heights. The method comprising steps of: preparing an object under test in which an electrode in a higher position have a higher surface roughness among the plurality of electrodes; bringing a plurality of sheet-type probes into contact with the plurality of electrodes, respectively; and supplying an electric current with the plurality of electrodes through the plurality of sheet-type probes. By implementing the method, the sheet-type probes can be kept in stable contact with the electrodes because electrodes in a higher position have a higher surface roughness Ra than electrodes in a lower position. Consequently, stable and reliable burn-in test can be performed.

Abstract: A thermally-assisted magnetic recording head is provided, in which a light source having sufficiently high output power for performing thermal-assist is disposed in the element-integration surface of the substrate to achieve improved mass-productivity. The head includes: a light source having a multilayered structure including a photonic-band layer and having a light-emitting surface opposed to the element-integration surface; a diffraction optical element that converges the emitted light; a light-path changer that changes the direction of the converged light; a waveguide that propagates the direction-changed light toward the opposed-to-medium surface; and a magnetic pole that generates write field. The surface-emitting type light source includes a photonic-band layer having a periodic structure in which a light from an active region resonates, and thus emits laser light on a quite different principle from a VCSEL.

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: In a method for manufacturing a thermally-assisted magnetic head that includes a slider and an LD unit, the slider including an air bearing surface (ABS) that faces a recording medium and including a waveguide with a core for light propagation that extends from a light entering surface, which is different from the ABS, to the ABS, the LD unit being attached to the light entering surface of the slider, and the thermally-assisted magnetic head performing magnetic recording while heating the recording medium with near-field light that is excited from linearly polarized laser light, the LD unit is disposed in a position facing the light entering surface of the slider, a photo detector is disposed in a position facing the ABS of the slider, and a polarizer transmitting only light having a polarization component that is orthogonal to a polarization direction of the linearly polarized laser light is disposed between the ABS and the photo detector.

Abstract: Provided is a thermally-assisted magnetic recording head in which NF-light with sufficiently high light density can be applied to a medium while a write-field generating point and a near-field light (NF-light) generating point are close to each other. The head comprises a plasmon generator provided between a magnetic pole and a waveguide and configured to be coupled with light propagating through the waveguide in a surface plasmon mode to emit NF-light. The plasmon generator comprises: a plasmon propagating part comprising a propagation edge for propagating surface plasmon excited by the light; and a light penetration suppressing part with an extinction coefficient greater than the plasmon propagating part. The light penetration suppressing part is in surface-contact with a surface portion of the plasmon propagating part excluding the propagation edge, and the magnetic pole is in surface-contact with the light penetration suppressing part.

Abstract: Provided is a surface plasmon resonating optical system emitting near-field light (NF-light) with a higher light density. The system comprises: a waveguide through which a light for exciting surface plasmon propagates; a plasmon generator that couples with the light in a surface plasmon mode and emits NF-light from its NF-light generating end surface; and a resonator mirror that reflects the excited surface plasmon, provided on the side of the plasmon generator opposite to the NF-light generating end surface. In the system, the excited surface plasmon can be amplified by using a resonator structure while reducing the length of the plasmon generator to reduce absorption of surface plasmon and prevent overheating of the plasmon generator.

Abstract: A thermally assisted magnetic head includes a slider and a light source unit. The light source unit includes a semiconductor laser diode. The semiconductor laser diode includes an n-type (Alx1Ga(1-x1))0.51In0.49P cladding layer, a p-type (Alx1Ga(1-x1))0.51In0.49P cladding layer, an n-side Alx2Ga(1-x2)As guide layer placed between these cladding layers, a p-side Alx2Ga(1-x2)As guide layer placed between these cladding layers, and an active layer placed between these guide layers.

Abstract: A magnetic film sensor comprises a magnetic film for generating a magnetostriction, and a magnetostrictive structure for generating a magnetostriction in the magnetic film. The magnetostrictive structure is constructed so as to generate a magnetostriction by curving the magnetic film, for example. The magnetostrictive structure is obtained, for example, by providing a depressed insulating layer having a surface formed with a depression and forming the magnetic film across the depression. A deformable part that is formed using a softer material than the magnetic film may also be formed at least partly on a surface of the magnetostrictive structure, within the depression.

Abstract: Provided is a near-field light transducer with a propagation edge in which the generation of defects is suppressed. The transducer is formed of a Ag alloy and comprises an edge, the edge comprising a portion to be coupled with a light in a surface plasmon mode, the edge extending from the portion to a near-field light generating end surface, and the edge being configured to propagate surface plasmon excited by the light. Further, a curvature radius of the rounded edge is set in the range from 6.25 nm to 20 nm. In the edge and its vicinity, the generation of defects such as cracking and chipping is suppressed. Thereby improved are a propagation efficiency of surface plasmon and a light use efficiency of the transducer. The Ag alloy preferably contains at least one element selected from a group of Pd, Au, Cu, Ru, Rh and Ir.

Abstract: Provided is a thermally-assisted magnetic recording head in which NF-light with sufficiently high light density can be applied to a medium while a write-field generating point and a near-field light (NF-light) generating point are close to each other. The head comprises a plasmon generator provided between a magnetic pole and a waveguide and configured to be coupled with light propagating through the waveguide in a surface plasmon mode to emit NF-light. The plasmon generator comprises: a plasmon propagating part comprising a propagation edge for propagating surface plasmon excited by the light; and a light penetration suppressing part with an extinction coefficient greater than the plasmon propagating part. The light penetration suppressing part is in surface-contact with a surface portion of the plasmon propagating part excluding the propagation edge, and the magnetic pole is in surface-contact with the light penetration suppressing part.

Abstract: A magnetic recording head capable of a satisfying thermally-assisted magnetic recording without depending on the use of a near-field light generator is provided. The head comprises a waveguide and a main magnetic pole having a main pole tip. Further, at least a portion of the main pole tip is embedded in a groove provided in the upper surface of the waveguide. Further, a second clad layer is provided on the first clad layer and on a rear side from the main pole tip. This configuration of the first and second clad layers suppresses the absorption of the light propagating through the waveguide by the main magnetic pole. Further, the configuration in which at least a portion of the main pole tip is embedded in the groove can cause the distance between the light spot center of the waveguide and the main magnetic pole to be sufficiently small.

Abstract: Provided is a method for manufacturing a thermally-assisted magnetic recording head including a light source unit with a light source and a slider with an optical system. The method comprises steps of: adhering by suction the light source unit with a back holding jig; moving the back holding jig, then aligning a light-emission center of the light source with a light-receiving end surface of the optical system in directions within a slider back surface of the slider; bringing the light source unit into contact with the slider back surface, with a suction surface of the back holding jig tilted from the normal to the slider back surface; applying a load to a load application surface of the unit substrate by a loading means to bring a joining surface of the light source unit into conformity with the slider back surface; and bonding the light source unit and the slider. This method can improve the conformity, thereby achieving adequately strong junction and adequately high accuracy in position.

Abstract: A waveguide has a core through which laser light can propagate in a TM mode, that has a rectangular cross section perpendicular to a propagative direction of the laser light, and through which the laser light can propagate in a fundamental mode in which only one portion exists on the cross section of the core where a light intensity of the laser light becomes maximal, and a higher order mode in which two or more portions exist where the light intensity becomes maximal, a clad surrounding the core, and a light absorbing element in the clad, and wherein a distance between the light absorbing element and the core is shorter than a penetration length of evanescent light in the higher order mode, but is longer than a penetration length of evanescent light in the fundamental mode.