Abstract: A thermally-assisted magnetic recording head includes a medium facing surface, a magnetic pole, a waveguide including a core and a cladding, and a plasmon generator. The magnetic pole is located forward of the core in the direction of travel of a magnetic recording medium. The plasmon generator is disposed between the core and the magnetic pole. The core has an evanescent light generating surface facing toward the plasmon generator. The plasmon generator has a front end face located in the medium facing surface, a flat surface facing toward the'evanescent light generating surface, and first and second side surfaces that are at a distance from each other and are located farther from the evanescent light generating surface than is the flat surface.

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, and 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. The plasmon generator has an end portion exposed at the air bearing surface or located in close proximity to the air bearing surface, the end portion having a minimum thickness in a region close to the waveguide.

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 magnetic recording element that faces a recording medium and that executes a magnetic recording while the recording medium is heated, the element including a waveguide that is configured with a core and a cladding, the core, through which laser light propagates, including an enlarged part, which is enlarged at an air bearing surface facing the recording medium; and the cladding surrounding a periphery of the core.

Abstract: The magnetic read write head has a read head and a write head, each having an end face exposed on an air bearing surface. The write head performs heat assist magnetic recording, and is provided with: a magnetic pole having an end face exposed on the air bearing surface; a waveguide extending toward the air bearing surface to propagate light; and a plasmon generator provided between the magnetic pole and the waveguide, and generating near-field light based on the light propagated through the waveguide to emit the generated near-field light from the air bearing surface. The waveguide is surrounded by a clad layer, and the magnetic pole is in contact with a heat sink having a heat conductivity higher than that of the clad layer. Although the near-field light causes temperature rise, heat energy from the plasmon generator to the magnetic pole is released through the heat sink.

Abstract: A measuring circuit system in a magnetic field measuring apparatus of the invention has an amplifier and a band-pass filter connected in sequence on an output terminal side of the TMR element, the band-pass filter is a narrow-range band-pass filter such that a peak pass frequency of the filter that is a center is a basic frequency selected from a range of 10 to 40 GHz and a band width centered around the basic frequency is a narrow range of ±0.5 to ±4 GHz; and with the measuring circuit system, an SIN ratio (SNR) of 3 dB or greater is obtained, the SNR being defined by a ratio of an amplitude S of a high-frequency generated signal induced by the TMR element to a total noise N that is a sum of a head noise generated by the TMR element and a circuit noise generated by the amplifier. With such a configuration, an in-plane high-frequency magnetic field generated by a microwave-assisted magnetic head is reliably and precisely measured.

Abstract: A thermally-assisted magnetic recording head includes: a medium facing surface; a magnetic pole; a waveguide including a core and a cladding; a plasmon generator; and a protruding member. The protruding member is disposed between the medium facing surface and a front end face of the core facing toward the medium facing surface. The protruding member has a first end face located in the medium facing surface, and a second end face facing toward the front end face of the core and receiving light having propagated through the core and passed through the front end face. The protruding member is formed of a metal different from both a material forming the magnetic pole and a material forming the plasmon generator. The protruding member is heated and expanded by the light received at the second end face, so that the first end face gets protruded toward a magnetic recording medium.

Abstract: Provided is a thermally-assisted magnetic recording head capable of setting the near-field light (NFL-) emission point to be sufficiently close to the write-field-generating portion. The head comprises a magnetic pole, a waveguide propagating light, and a NFL-generator coupled with the light in surface plasmon mode. The NFL-generator comprises a propagation edge extending to the NFL-generating end surface, at least a portion of the propagation edge being opposed to the waveguide with a distance, and the magnetic pole has a surface contact with a surface portion of the NFL-generator including no propagation edge. Therefore, the distance between the magnetic-pole end surface and the NFL-generating end surface becomes zero. The propagation edge is not contacted with the magnetic pole. Accordingly, the surface plasmon can propagate along on the propagation edge without being absorbed by the pole. Thus, the NFL-emission point is ensured to be at the end point of the propagation edge.

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 microwave assisted magnetic head of the present invention includes: at least two or more auxiliary coils that are arranged in a periphery of a writing main pole; and microwave current supply means that applies microwave currents to the at least two or more auxiliary coils. The at least two or more auxiliary coils respectively include linear body parts linearly arranged on an ABS side, two of the linear body parts of the at least two or more auxiliary coils are arranged in a substantially orthogonal positional relationship, and the microwave current supply means is configured such that the microwave current supply means changes phase differences of the microwave currents applied respectively to the at least two or more auxiliary coils. Therefore, the microwave current can be easily controlled, and thus, a circularly polarized magnetic field with high magnetization inversion efficiency can be generated as an assistance magnetic field.

Abstract: A microwave assisted magnetic head of the present invention includes: at least two or more auxiliary coils that are arranged in a periphery of a writing main pole; and microwave current supply means that applies microwave currents to the at least two or more auxiliary coils. The at least two or more auxiliary coils respectively include linear body parts linearly arranged on an ABS side, two of the linear body parts of the at least two or more auxiliary coils are arranged in a substantially orthogonal positional relationship, and the microwave current supply means is configured such that the microwave current supply means changes phase differences of the microwave currents applied respectively to the at least two or more auxiliary coils. Therefore, the microwave current can be easily controlled, and thus, a circularly polarized magnetic field with high magnetization inversion efficiency can be generated as an assistance magnetic field.

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, and 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. The plasmon generator has an end portion exposed at the air bearing surface or located in close proximity to the air bearing surface, the end portion having a minimum thickness in a region close to the waveguide.

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: 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: The magnetic read write head has a read head and a write head, each having an end face exposed on an air bearing surface. The write head performs heat assist magnetic recording, and is provided with: a magnetic pole having an end face exposed on the air bearing surface; a waveguide extending toward the air bearing surface to propagate light; and a plasmon generator provided between the magnetic pole and the waveguide, and generating near-field light based on the light propagated through the waveguide to emit the generated near-field light from the air bearing surface. The waveguide is surrounded by a clad layer, and the magnetic pole is in contact with a heat sink having a heat conductivity higher than that of the clad layer. Although the near-field light causes temperature rise, heat energy from the plasmon generator to the magnetic pole is released through the heat sink.

Abstract: An orthogonalizing bias function part formed at a rear part of an MR part in a DFL structure influencing a substantial orthogonalizing function of first and second ferromagnetic layers in respective magnetization directions thereof, non-magnetic metal layers formed to abut both ends of the MR part in a width direction and separated from both ends of the MR part by respective insulation layers, each of the non-magnetic metal layers being in a two-layer structure configured with a first non-magnetic metal layer positioned at a lower side as a lower layer and a second non-metal layer positioned at an upper side as an upper layer are configured, and relationship R2<R1 is met, where R1 is a milling rate for the first non-magnetic metal layer that is the lower layer, and R2 is another milling rate for the second non-magnetic metal layer that is the upper layer.

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 magnetic recording element that faces a recording medium and that executes a magnetic recording while the recording medium is heated, the element including a waveguide that is configured with a core and a cladding, the core, through which laser light propagates, including an enlarged part, which is enlarged at an air bearing surface facing the recording medium; and the cladding surrounding a periphery of the core.

Abstract: A magnetic recording apparatus includes a magnetic recording medium having a magnetic recording layer, a thin-film magnetic head with a microwave-band magnetic drive function, the head having a write field generation means that generates a write field to the magnetic recording medium in response to a write signal, and a microwave generator that is provided independent of the write field generation means and generates an alternating magnetic field in plane having a microwave-band frequency when microwave-excitation current is fed, an excitation current generation means that generates the microwave-excitation current by amplitude-modulating microwave carrier current with a modulating signal having a fixed period, and a write signal supply means that generates the write signal and applies it to the write field generation means of the thin-film magnetic head.

Abstract: An outer surface of a plasmon generator includes: a plasmon exciting part that faces an evanescent light generating surface with a predetermined distance therebetween; and a front end face located in a medium facing surface. The plasmon generator has: first and second sidewall parts that are connected to the plasmon exciting part and increase in distance from each other with increasing distance from the plasmon exciting part; and at least one extended portion connected to an edge of at least one of the first and second sidewall parts opposite from the plasmon exciting part. A magnetic pole has a portion interposed between the first and second sidewall parts. The front end face includes first and second portions lying at ends of the first and second sidewall parts and connected to each other into a V-shape. An end face of the magnetic pole has a portion interposed between the first and second portions of the front end face.