Abstract: The present disclosure generally relates to a magnetic recording head for a magnetic media drive. The magnetic recording head comprises a near field transducer (NFT), a vertical cavity surface emitting laser (VCSEL) device, and a waveguide structure coupled between the NFT and the VCSEL device. The waveguide structure comprises a plurality of waveguide channels and a multimodal interference (MMI) combiner coupled to the waveguide channels. One or more of a curvature, a path length, and a propagation length of each of the waveguide channels is optimized such that each waveguide channel is controllable, or otherwise phase coherent with adjacent waveguide channels. The VCSEL device is capable of emitting a plurality of lasers through the plurality of waveguide channels, and the plurality of lasers are phase coherent when input into the MMI combiner. The MMI combiner combines a power of the plurality of lasers, which is output to the NFT.

Abstract: A heat-assisted magnetic recording (HAMR) head for recording data in data tracks of a HAMR disk has a gas-bearing slider that supports a near-field transducer (NFT) and a main magnetic pole formed of two layers. The first main pole layer has a cross-track width at the slider's gas-bearing surface (GBS) that tapers down in the direction towards the NFT where the optical spot is formed. The second main pole layer is located away from the NFT and has a substantially wider cross-track width than the first main pole layer so as to provide sufficient magnetic field for writing. Layers of heat sink material are located on the sloped cross-track sides of the tapered first main pole layer to reduce the temperature and thus the likelihood of oxidation of the main pole layers.

Abstract: The present disclosure relates to pretreating a magnetic recording head for magnetic media drive. For a heat assisted magnetic recording (HAMR) head, a light source provides the necessary heat for the drive to operation. A vertical cavity surface emitting laser (VCSEL) is mounted to a top surface of a slider. A plurality of laser beams are emitted from the bottom surface of the VCSEL and directed to a corresponding number of waveguide structures within the HAMR head. The waveguide structures feed into a multimode interference (MMI) device that then directs the laser into a single waveguide for focusing on a near field transducer (NFT). The VCSEL lasers are phase coherent and have no mode hopping.

Abstract: The present disclosure relates to pretreating a magnetic recording head for magnetic media drive. For a heat assisted magnetic recording (HAMR) head, a light source provides the necessary heat for the drive to operation. A vertical cavity surface emitting laser (VCSEL) is mounted to a top surface of a slider. A plurality of laser beams are emitted from the bottom surface of the VCSEL and directed to a corresponding number of waveguide structures within the HAMR head. The waveguide structures feed into a multimode interference (MMI) device that then directs the laser into a single waveguide for focusing on a near field transducer (NFT). The VCSEL lasers are phase coherent and have no mode hopping.

Abstract: A non-oriented electrical steel sheet including a base metal that has a chemical composition including, in mass %, C: 0.0010 to 0.0040%, Si: 3.5 to 4.9%, Mn: 0.05 to 0.20%, Al: 0.05 to 0.45%, P: 0.030% or less, S: 0.0030% or less, N: 0.0030% or less, O: 0.0100 to 0.0400%, Ca: less than 0.0010%, Ti: less than 0.0050%, Nb: less than 0.0050%, Zr: less than 0.0050%, V: less than 0.0050%, Cu: less than 0.20%, Ni: less than 0.50%, Sn: 0 to 0.05%, Sb: 0 to 0.05%, and a balance: Fe and impurities, and satisfying [4.0?Si+Al?5.0], in which the base metal has an O content of less than 0.0050% in a region excluding a portion from a surface of the base metal to a position of 10 ?m in a depth direction of the base metal.

Abstract: A non-oriented electrical steel sheet including a base metal that has a chemical composition including, in mass%, C: 0.0010 to 0.0040%, Si: 4.0 to 5.0%, Mn: 0.20% or less Al: 0.010% or more and less than 0.050%, P: 0.030% or less, S: 0.0030% or less, N: 0.0005 to 0.0030%, O: 0.0100 to 0.0400%, Ca: less than 0.0010%, Ti: less than 0.0050%, Nb: less than 0.0050%, Zr: less than 0.0050%, V: less than 0.0050%, Cu: less than 0.20%, Ni: less than 0.50%, Sn: 0 to 0.05%, Sb: 0 to 0.05%, and a balance: Fe and impurities, in which the base metal has an O content of less than 0.0050% in a region excluding a portion from a surface of the base metal to a position of 10 µm in a depth direction of the base metal.

Abstract: A chemical composition of a base metal of a non-oriented electrical steel sheet contains, by mass %, C: 0.0050% or less, Si: 3.8% to 5.0%, Mn: exceeding 0.2% and less than 2.0%, P: 0.030% or less, S: 0.0030% or less, Al: 0.005% or more and less than 0.050%, N: 0.0005% to 0.0030%, Ti: less than 0.0050%, Nb: less than 0.0050%, Zr: less than 0.0050%, V: less than 0.0050%, Cu: less than 0.20%, Ni: less than 0.50%, Sn: 0% to 0.10%, Sb: 0% to 0.10%, a remainder: Fe and impurities. [Si+0.5×Mn?4.3] is satisfied and the average grain size of the base metal is in a range of 10 to 80 ?m.

Abstract: According to one embodiment, a magnetic disk device includes a rotatable disk-shaped recording medium, a magnetic head including a write head having a main magnetic pole that applies a recording magnetic field to the recording medium, an assist element that assists magnetic recording by the main magnetic pole, and a plurality of thermal actuators that control a head gradient with respect to the recording medium, and a controller which includes a detection unit configured to detect deterioration of the magnetic head, and changes a head gradient of the magnetic head by the thermal actuator according to the detected deterioration.

Abstract: According to one embodiment, a magnetic disk device comprises a magnetic disk, a magnetic head, a monitoring unit, and a control unit. When carrying out write of data to a first track, if an absolute difference between a light output monitored by the monitoring unit at the time of write and a light output monitored last time by the monitoring unit exceeds a predetermined value, the control unit controls a position of a write head and writes data again to the first track or a second track one track before the first track.

Abstract: According to one embodiment, a magnetic disk device comprises a magnetic disk, a magnetic head, a monitoring unit, and a control unit. When carrying out write of data to a first track, if an absolute difference between a light output monitored by the monitoring unit at the time of write and a light output monitored last time by the monitoring unit exceeds a predetermined value, the control unit controls a position of a write head and writes data again to the first track or a second track one track before the first track.

Abstract: This work machine is provided with a clutch mechanism which is provided on a motive power transmission path between a drive source and a wheel. The clutch mechanism is provided with: a drive shaft with which drive force from the drive source is transmitted; a key member which is provided so as to be capable of moving relative to the drive shaft; a driven member which is driven by the drive shaft via the key member; an impelling member which impels the key member towards the driven member; and a ratchet holder which is provided with an engagement groove and a guide part, and which is provided so as to be capable of rotating coaxially with the drive shaft.

Abstract: A lawn mower includes a blade, a motor connected to the blade, and a housing storing the blade in the housing and is configured to mow grass underneath the housing. The lawn mower includes a grass container to contain the mowed grass and a connecting member that connects the housing to the grass container. The housing is provided with a ceiling opening communicating with a flow path inside the connecting member. The ceiling opening overlaps with a region corresponding to a rotation range, of the blade, projected upward along a drive shaft.

Abstract: Embodiments of the present disclosure generally relate to a vertical cavity surface emitting laser (VCSEL), a head gimbal assembly for mounting a VCSEL, devices incorporating such articles, and to a process for forming a VCSEL. In an embodiment, a process for forming a VCSEL device is provided. The process includes forming a trench in a substrate, forming two laser diode electrodes in the trench, and after forming the two laser diode electrodes, cutting the substrate along the trench to form a VCSEL, the VCSEL comprising a chip for mounting on a slider, the chip having six surfaces, wherein a first surface of the chip is for facing the slider, a second surface of the chip is opposite the first surface, the two laser diode electrodes being positioned in any combination on one or more of a third surface, a fourth surface, a fifth surface, or a sixth surface.

Abstract: Embodiments of the present disclosure generally relate to a vertical cavity surface emitting laser (VCSEL), a head gimbal assembly for mounting a VCSEL, devices incorporating such articles, and to a process for forming a VCSEL. In an embodiment, a VCSEL device provided. The VCSEL device includes a chip for mounting on a slider, the chip having a plurality of surfaces and a notch, the plurality of surfaces comprising: a bottom surface for facing the slider; a top surface opposite the bottom surface; and a plurality of side surfaces, wherein the notch forms a recessed edge spaced away from the bottom surface and toward the top surface, the notch having a shoulder, a side, and an angle (?1) between the shoulder and the side. The VCSEL device further includes two laser diode electrodes positioned in any combination on one or more of the plurality of surfaces of the chip.

Abstract: Embodiments of the present disclosure generally relate to a vertical cavity surface emitting laser, a head gimbal assembly for mounting a vertical cavity surface emitting laser, and devices incorporating such articles. In an embodiment, a vertical cavity surface emitting laser (VCSEL) device is provided. The VCSEL device includes a chip for mounting on a slider and two laser diode electrodes. The chip has six surfaces, wherein a first surface of the chip is for facing the slider, a second surface of the chip is opposite the first surface, and the two laser diode electrodes are positioned in any combination on one or more of a third surface, a fourth surface, a fifth surface, or a sixth surface of the chip.

Abstract: A heat-assisted magnetic recording (HAMR) head has a slider with a gas-bearing-surface (GBS). The slider supports a near-field transducer (NFT) and a main magnetic pole that has a step or recess in the NFT-facing surface near the GBS that contains plasmonic material. A thermal shunt is located between the NFT and the main pole to allow heat to be transferred away from the optical spot generated by the NFT. The NFT-facing surface of the main pole that is recessed from the step away from the GBS is in contact with the thermal shunt, and the thermal shunt is in contact with the plasmonic material in the step in the back region recessed from the GBS, so there is no increase in the spacing between the NFT and a large portion of the main pole.

Abstract: A heat-assisted magnetic recording (HAMR) disk drive uses a semiconductor laser mounted on a slider to deliver light to a near-field transducer (NFT) via a waveguide located inside the slider. The waveguide includes a core and cladding material that is transparent to the laser light and surrounds the core. Layers of stray light absorption material are located inside the slider on opposite edges of the waveguide core in the same plane as the core and on opposite sides of the waveguide core in planes spaced from the plane of the core. Portions of the waveguide cladding material are located between the waveguide core and the stray light absorption layers. The stray light absorption layers absorb light that leaks into the cladding material and substantially reduces stray light reflected to the laser to prevent undesirable laser power fluctuation.

Abstract: According to one embodiment, a magnetic disk device includes a recording medium, a recording head including a main magnetic pole, a write shield magnetic pole, a coil, and a spin torque oscillator provided between the main magnetic pole and the write shield magnetic pole and a controller including a record current supply circuit and a drive current supply circuit. The controller executes a process of monitoring variation of a resistance value of the spin torque oscillator while increasing the record current in a state in which the spin torque oscillator is energized and detecting a record current value when the resistance value is increased most largely, and a process of setting the detected record current value to a lower limit of the record current supplied to the coil.

Abstract: An electrical steel sheet is described, which has an insulating coating on its surface. The insulating coating is free of chromium and comprises plate-like particles of inorganic compound and a metal phosphate. The plate-like particles of inorganic compound are in the form of secondary particles, which are formed by aggregating primary particles, and present in an amount of not less than 0.1 parts by mass and not greater than 20 parts by mass, with respect to 100 parts by mass of the metal phosphate. The secondary particles have an average particle diameter of no less than 0.05 ?m and no greater than 5 ?m, and have a specific surface area of 1 to 80 m2/g. The primary particles have an aspect ratio of 50 to 1000. The electrical steel sheet has excellent heat resistance, corrosion resistance, appearance, and insulating properties.

Abstract: A heat-assisted magnetic recording (HAMR) head for recording data in data tracks of a HAMR disk has a gas-bearing slider that supports a near-field transducer (NFT) and a main magnetic pole formed of two layers. The first main pole layer has a cross-track width at the slider's gas-bearing surface (GBS) that tapers down in the direction towards the NFT where the optical spot is formed. The second main pole layer is located away from the NFT and has a substantially wider cross-track width than the first main pole layer so as to provide sufficient magnetic field for writing. Layers of heat sink material are located on the sloped cross-track sides of the tapered first main pole layer to reduce the temperature and thus the likelihood of oxidation of the main pole layers.