Abstract: Provided is a thermally-assisted magnetic recording head comprising a near-field-light-generating (NFL-generating) optical system with an improved light use efficiency. The head comprises a magnetic pole, a waveguide propagating a light for exciting surface plasmon, and a NF-optical device configured to emit NF-light from its end surface located adjacent to the magnetic pole end surface. The waveguide cross-section, taken by a plane perpendicular to a waveguide edge along elongated direction, has substantially a trapezoidal shape in which a longer side of opposed parallel sides is an edge of the cross-section on the NF-optical device side. This configuration enables a coupled portion of the NF-optical device which is coupled with the light to be placed in the effective distribution range of the light seeping from the waveguide. Consequently, there can be realized a sufficiently strong coupling between the light seeping from the waveguide and the NF-optical device.

Abstract: An optical waveguide of the invention includes a core that is a waveguide through which light propagates; and a cladding that surrounds the core. The core has a plate shape and includes a wide core base part onto which the light is incident, a taper part that is connected to the core base part and of which a width is gradually tapered along a propagation direction, and a narrow front end core part that is connected to the taper part and that extends along the propagation direction.

Abstract: A heat-assisted magnetic write head includes a magnetic pole having an end surface exposed at an air bearing surface, a waveguide extending toward the air bearing surface to propagate light, a first pair of clads made of a first dielectric material having a refractive index lower than that of the waveguide, and sandwiching the waveguide in a track width direction, and a second pair of clads made of a second dielectric material having a refractive index lower than that of the first dielectric material, and sandwiching the waveguide in a thickness direction orthogonal to the track width direction. Further, the heat-assisted magnetic write head may include, between the magnetic pole and the waveguide, a plasmon generator generating near-field light from the air bearing surface, based on light propagating through the waveguide.

Abstract: A spot size converter according to the present invention is capable of shortening the waveguide length in the spot size converter and of promoting a size reduction of the optical waveguide itself because two cores having a taper portion are combined and those tapering angles are mutually aligned. Furthermore, spot size conversion efficiency is favorable even in a small size.

Abstract: A near-field light generator includes a waveguide, a plasmon generator, and a metal layer. The waveguide includes a core having an evanescent light generating surface. The plasmon generator includes a base part, and a protruding part that protrudes from the base part toward the evanescent light generating surface. The protruding part has: a front end face located at an end in a direction parallel to the evanescent light generating surface; a band-shaped flat surface facing toward the evanescent light generating surface; and two side surfaces connected to the flat surface. In at least a portion of the protruding part, the distance between the two side surfaces increases with increasing distance from the evanescent light generating surface. The flat surface includes a first portion contiguous with the front end face, and a second portion that is located farther from the front end face than is the first portion. The metal layer has an end face facing the first portion.

Abstract: A magneto-resistive effect (MR) element includes first and second magnetic layers in which a relative angle formed by magnetization directions changes in response to an external magnetic field, and a spacer layer positioned between the first magnetic layer and the second magnetic layer. The first magnetic layer is positioned closer to a substrate above which the MR element is formed than the second magnetic layer. The spacer layer includes a copper layer, a metal intermediate layer and a main spacer layer composed of gallium oxide as a primary component. The copper layer and the metal intermediate layer are positioned between the main spacer layer and the first magnetic layer. The metal intermediate layer is positioned between the copper layer and the main spacer layer.

Abstract: A magneto-resistive effect (MR) element includes: first and second magnetic layers in which a relative angle formed by magnetization directions changes according to an external magnetic field; and a spacer layer positioned between the first magnetic layer and the second magnetic layer. The spacer layer includes a main spacer layer composed of gallium oxide as a primary component and containing at least one metal element selected from a group of magnesium, zinc, indium and aluminum.

Abstract: A heat-assisted magnetic write head includes: a magnetic pole having an end surface exposed to an air bearing surface; a waveguide extending toward the air bearing surface to propagate light; a plasmon generator provided between the magnetic pole and the waveguide and generating near-field light from the air bearing surface, based on the light propagated through the waveguide; and a clad provided to surround both the waveguide and the plasmon generator collectively, the clad having a refractive index lower than that of the waveguide, and exhibiting a thermal conductivity higher than that of the waveguide. The clad may be provided to collectively surround the magnetic pole, as well.

Abstract: A magneto-resistive effect (MR) element includes first and second magnetic layers in which a relative angle formed by magnetization directions changes in response to an external magnetic field, and a spacer layer positioned between the first magnetic layer and the second magnetic layer. The spacer layer, on an air bearing surface, has a larger film thickness at both side edge parts in a track width direction than a film thickness at a central part in a track width direction. When a region of the spacer layer on the air bearing surface is divided into quarters which are both side edge part regions and two central regions such that track width direction lengths are equivalent, an average film thickness of a region where the both side edge regions are combined is preferably larger than a region where the two central regions are combined.

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: 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: An MR element includes a stack, being a pillar or trapezoidal stack, including first and second magnetic layers in which a relative angle formed by magnetization directions changes according to an external magnetic field, and a spacer layer that is positioned between the first magnetic layer and the second magnetic layer, and that is provided with a main spacer layer that is composed of gallium oxide, zinc oxide or magnesium oxide as a primary component, wherein, one part of side surfaces of the stack forms a part of an air bearing surface; and a cover layer that covers at least another part of the side surfaces of the stack and that is composed of gallium oxide as a primary component.

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 magnetoresistive effect element (MR element) includes first and second magnetic layers of which relative angles formed by magnetization directions change in relation to an external magnetic field; and a spacer layer positioned between the first magnetic layer and the second magnetic layer. The first magnetic layer is positioned on a side closer than the second magnetic layer in regards to a substrate above which the magnetoresistive effect element is formed, and the spacer layer includes a main spacer layer made of gallium oxide as the primary component, and a first nonmagnetic layer positioned between the main spacer layer and the first magnetic layer and contains copper and gallium.

Abstract: A thermally-assisted magnetic recording head includes a waveguide, a near-field optical device which emits near-field light from a near-field-light-generating end surface that forms a portion of an opposed-to-medium surface, and a magnetic pole generates write field from its end on the opposed-to-medium surface side. The near-field optical device includes a contact-to-waveguide surface, and a propagation edge configured to propagate there on the surface plasmon excited by the light. A gap between a near-field optical device-opposed surface of the magnetic pole and the propagation edge of the near-field optical device is larger at a section far from the end on the opposed-to-medium surface side than that at a section near the opposed-to-medium surface side.

Abstract: In an MR element of the present invention, an effect of an extremely-high MR ratio is obtained since a crystal structure of a CoFe magnetic layer in the vicinity of an interface with a spacer layer is formed as a close packed structure, such as an hcp structure and an fcc structure, and a total existing ratio of these crystal structures is 25% or more by an area ratio.

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.