Abstract: A plasmon generator has an outer surface including a propagation edge, and has a near-field light generating part lying at an end of the propagation edge and located in a medium facing surface. The propagation edge faces an evanescent light generating surface of a waveguide's core with a predetermined distance therebetween and extends in a direction perpendicular to the medium facing surface. The propagation edge is arc-shaped in a cross section parallel to the medium facing surface. The plasmon generator includes a shape changing portion in which a radius of curvature of the propagation edge in the cross section parallel to the medium facing surface continuously decreases with decreasing distance to the medium facing surface.

Abstract: A plasmon generator has a near-field light generating part located in a medium facing surface. The plasmon generator has an outer surface including a plasmon exciting surface and a plasmon propagating surface that face toward opposite directions. The plasmon exciting surface is substantially in contact with an evanescent light generating surface of a waveguide's core. The plasmon propagating surface is in contact with a dielectric layer that has a refractive index lower than that of the core. The plasmon exciting surface includes a first width changing portion. The plasmon propagating surface includes a second width changing portion. Each of the first and second width changing portions has a width that decreases with decreasing distance to the medium facing surface, the width being in a direction parallel to the medium facing surface and the evanescent light generating surface.

Abstract: When first and second near-field light-generating portions are irradiated with laser light or other energy rays, near-field light is generated at the tips of both the near-field light-generating portions. By means of the near-field light thus generated, a magnetic recording medium opposing the medium-opposing surface is heated, and the coercivity of the magnetic recording medium is lowered. Since at least a portion of the main magnetic pole is positioned within the spot region including the region between the first and second near-field light-generating portions, the tips of both the near-field light-generating portions and the main magnetic pole can be brought extremely close together, and high-density recording can be performed.

Abstract: A near-field light generating device includes: a base having a top surface; a waveguide that allows laser light to propagate therethrough and is disposed above the top surface of the base; and a surface plasmon generating element that is disposed above the top surface of the base so as to adjoin the waveguide in a direction parallel to the top surface of the base. The waveguide has a side surface that faces the surface plasmon generating element. The surface plasmon generating element includes: a coupling part that is opposed to a part of the side surface of the waveguide with spacing therebetween and causes excitation of a surface plasmon by coupling with evanescent light occurring from the part of the side surface; and a near-field light generating part that generates near-field light based on the surface plasmon excited at the coupling part.

Abstract: A heat-assisted magnetic recording head includes a slider, and an edge-emitting laser diode fixed to the slider. The slider includes: a substrate; and an MR element, two reproduction wiring layers, a coil, two recording wiring layers, a magnetic pole, a near-field light generating element, and a waveguide that are stacked above the top surface of the substrate. The two reproduction wiring layers supply a sense current to the MR element. The two recording wiring layers supply a coil current to the coil, The laser diode has an emitting end face including an emission part for emitting laser light, and a bottom surface, The laser diode is arranged so that the bottom surface faces the top surface of the slider. As viewed from above, the laser diode does not overlap the two reproduction wiring layers but overlaps at least one of the two recording wiring layers.

Abstract: Provided is a thermally-assisted magnetic recording head with improved light density of near-field light (NF-light) with which a medium is irradiated. The head comprises: a magnetic pole; a waveguide for propagating light for exciting surface plasmon; a surface plasmon generator provided between the magnetic pole and the waveguide, coupled with the light in a surface plasmon mode, and emitting NF-light; and a clad portion provided at least between the waveguide and the surface plasmon generator and comprising a transition region in which a refractive index decreases along a direction from the waveguide toward the magnetic pole. The provision of the clad portion including the transition region enables improvement of the light density of NF-light due to the convergence of surface plasmon excited in the surface plasmon generator to predetermined locations, while avoiding the problem of temperature rise due to reduction of the volume of surface plasmon generator.

Abstract: Provided is a near-field light generating element in which reduced is the propagation loss of excited surface plasmon that propagates to the near-field light generating end. The element comprises: a waveguide through which light for exciting surface plasmon propagates; and a plasmon antenna comprising a near-field light generating end and a propagation surface or edge. The propagation surface or edge extends to the near-field light generating end, and causes surface plasmon excited by the light to propagate thereon. Further, a portion of the side surface on the near-field light generating end side is opposed to the propagation surface or edge with a predetermined distance so as for the light to be coupled with the plasmon antenna in a surface plasmon mode. In this configuration, surface plasmon can propagates without significantly changing its wavenumber, which leads to a less propagation loss, and to an improved light use efficiency.

Abstract: An optical waveguide, on account of its ability to apply phase resonance of a wavelength and of a first and second triangular plate-like spot size converter members formed of the same material as a core material and being arranged and formed in a substantially symmetrical structure, can promote shortening of the waveguide length and contrive to reduce the size of the optical waveguide itself. Further, an optical waveguide having excellent spot size conversion efficiency can be obtained even in a reduced size.

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 plasmon generator has an outer surface including a surface plasmon exciting surface, and has a near-field light generating part located in a medium facing surface. The surface plasmon exciting surface is a flat surface that faces an evanescent light generating surface of a waveguide with a predetermined distance therebetween. The surface plasmon exciting surface includes a width changing portion. The width of the width changing portion in a direction parallel to the medium facing surface and the evanescent light generating surface decreases with decreasing distance to the medium facing surface. A magnetic pole is located at such a position that the plasmon generator is interposed between the magnetic pole and the waveguide. The outer surface of the plasmon generator includes a pole contact surface that is in contact with the magnetic pole.

Abstract: A near-field light generating device includes: a waveguide having a groove that opens in the top surface; a clad layer disposed on the top surface of the waveguide and having an opening that is contiguous to the groove; a near-field light generating element accommodated in the opening; and a buffer layer interposed between the near-field light generating element and each of the waveguide and the clad layer in the groove and the opening. The near-field light generating element includes: first and second side surfaces that decrease in distance from each other toward the groove; an edge part that connects the first and second side surfaces to each other and is opposed to the groove with the buffer layer therebetween; and a near-field light generating part that lies at one end of the edge part and generates near-field light.

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 head has a medium-facing surface facing a magnetic recording medium; a near-field light generator disposed on a light exit face in the medium-facing surface; a magnetic recording element located adjacent to the near-field light generator; and a light emitting element disposed so that emitted light thereof reaches the near-field light generator; the near-field light generator is comprised of a cusp portion and a base portion; when ?in represents a wavelength of the emitted light from the light emitting element immediately before the emitted light reaches the near-field light generator, an intensity of near-field light generated when the material forming the cusp portion is irradiated with the light of the wavelength ?in is stronger than an intensity of near-field light generated when the material forming the base portion is irradiated with the light of the wavelength ?in.

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

Abstract: Provided is a manufacturing method of heat-assisted magnetic recording head, in which a light source unit can be easily joined to a slider with sufficiently high accuracy, under avoiding the excessive mechanical stress. The manufacturing method comprises the steps of: moving relatively the light source unit and the slider, while applying a sufficient voltage between an upper electrode of the light source and an electrode layer provided in the slider; and setting the light source unit and the slider in desired positions in a direction perpendicular to the element-integration surface of the slider substrate. The desired positions are positions where the light source just emits due to a surface contact between: the protruded portion of the lower surface of the light source; and the upper surface of the electrode layer, which is a portion of the wall surface of a step formed on the head part.

Abstract: Provided is a near-field light generating element in which as much amount as possible of waveguide light can be coupled with a plasmon antenna. The element comprises a light waveguide and a plasmon antenna comprising a surface or edge for propagating surface plasmon excited by waveguide light, extending to a near-field light generating end. A groove is formed in a waveguide side surface. And at least a portion of the surface or edge is embedded in the groove or located directly above the groove, being opposed to a wall or bottom surface of the groove with a predetermined distance, so as for waveguide light to be coupled with the plasmon antenna in surface plasmon mode. This configuration enables the surface or edge to be located at the position in which the surface or edge can be coupled with more amount of light, thereby to improve the light use efficiency.

Abstract: A near-field light generating device includes: a waveguide; a buffer layer disposed on the top surface of the waveguide; an adhesion layer that is formed by incompletely oxidizing a metal layer and disposed on the buffer layer; and a near-field light generating element disposed on the adhesion layer. The adhesion layer has a resistance-area product higher than that of the metal layer unoxidized and lower than that of a layer that is formed by completely oxidizing the metal layer. A layered structure consisting of the buffer layer, the adhesion layer and the near-field light generating element has a peel-test adhesive strength higher than that of a layered structure consisting of the buffer layer and the near-field light generating element.

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.

Abstract: A plasmon generator has an outer surface including a plasmon exciting part, and has a near-field light generating part located in a medium facing surface. The plasmon exciting part faces an evanescent light generating surface of a waveguide's core with a predetermined distance therebetween. The outer surface of the plasmon generator further includes first and second inclined surfaces that are each connected to the plasmon exciting part. The first and second inclined surfaces increase in distance from each other with increasing distance from the plasmon exciting part. The plasmon generator includes a shape changing portion where the angle of inclination of each of the first and second inclined surfaces with respect to the evanescent light generating surface increases continuously with decreasing distance to the medium facing surface.

Abstract: A plasmon generator has an outer surface including a propagation edge, and has a near-field light generating part lying at an end of the propagation edge and located in a medium facing surface. The propagation edge faces an evanescent light generating surface of a waveguide's core with a predetermined distance therebetween and extends in a direction perpendicular to the medium facing surface. The propagation edge is arc-shaped in a cross section parallel to the medium facing surface. The plasmon generator includes a shape changing portion in which a radius of curvature of the propagation edge in the cross section parallel to the medium facing surface continuously decreases with decreasing distance to the medium facing surface.