Abstract: Aspects of the present disclosure generally relate to a magnetic recording head of a spintronic device, such as a write head of a data storage device, for example a magnetic media drive. In one example, a magnetic recording head includes a main pole, a trailing shield, and a spin torque layer (STL) between the main pole and the trailing shield. The magnetic recording head a first layer structure on the main pole, and the first layer structure includes a negative polarization layer. The magnetic recording head also includes a second layer structure disposed on the negative polarization layer and between the negative polarization layer and the STL. The negative polarization layer is an FeCr layer. The second layer structure includes a Cr layer disposed on the FeCr layer, and a Cu layer disposed on the Cr layer and between the Cr layer and the STL.

Abstract: An iris image acquisition system for a mobile device, comprises a lens assembly arranged along an optical axis and configured for forming an image comprising at least one iris of a subject disposed frontally to the lens assembly; and an image sensor configured to acquire the formed image. The lens assembly comprises a first lens refractive element and at least one second lens element for converging incident radiation to the first refractive element. The first refractive element has a variable thickness configured to counteract a shift of the formed image along the optical axis induced by change in iris-lens assembly distance, such that different areas of the image sensor on which irises at different respective iris-lens assembly distances are formed are in focus within a range of respective iris-lens assembly distances at which iris detail is provided at sufficient contrast to be recognised.

Abstract: Embodiments of the present disclosure generally relate to a write head for a magnetic recording device. The write head includes a spin torque oscillator (STO) that has a seed layer formed on a write pole, a spin polarization layer (SPL) formed on the seed layer, a first spacer layer formed on the SPL, a field generation layer (FGL) formed on the first spacer layer, a second spacer layer formed on the FGL, and a notch formed on the second spacer layer. The FGL and the notch are antiferromagnetically coupled through the second spacer layer and thus increases the FGL angle and improves the write capabilities of the write head.

Abstract: Disclosed herein are magnetic write heads and methods of designing them, and data storage devices comprising such write heads. A magnetic write head having leading and trailing sides comprises an air-bearing surface (ABS), a main pole between the leading and trailing sides, a first return pole between the main pole and the leading side, at least one optical near-field generator between the first return pole and the main pole, and a second return pole between the main pole and the trailing side. The main pole comprises a first tapered portion comprising a leading-side edge perpendicular to the ABS, a first trailing-side edge at a first angle to the ABS, and a second trailing-side edge recessed from the ABS and at a second angle to the ABS. The second return pole comprises a second tapered portion adjacent to the ABS and extending toward the main pole.

Abstract: A write head for a data storage device comprises a main pole, a trailing shield, and a write-field enhancement structure disposed in a write gap between the main pole and the trailing shield. The write-field enhancement structure comprises a non-magnetic spacer, a non-magnetic layer, and a magnetic DC-field-generation (DFG) layer. The DFG layer is sandwiched between the non-magnetic layer and the non-magnetic spacer. The write head also includes at least one magnetic notch adjacent to at least one of the main pole or the trailing shield. The non-magnetic spacer is adjacent to a magnetic notch. Some embodiments include multiple magnetic notches. Also disclosed are data storage devices comprising such write heads.

Abstract: The present disclosure generally relates to data storage devices, and more specifically, to a magnetic media drive employing a magnetic recording head. A magnetic recording head comprises a main pole disposed between a leading shield and a trailing shield. A spin torque oscillator is disposed between the main pole and the trailing shield at a media facing surface. A hot seed bilayer is disposed between the spin torque oscillator and the trailing shield, where the hot seed bilayer is conformal with the spin torque oscillator. The hot seed bilayer comprises a first layer comprised of a high magnetic moment material disposed at the media facing surface and a second layer comprised of a low magnetic material recessed from the media facing surface.

Abstract: A magnetic recording head is disclosed having a main pole, a shield hot seed layer positioned at a first side of the main pole, a first material positioned at both a second side and a third side of the main pole, the first material connected to the main pole, a second material positioned adjacent to the first material on the second side and the third side of the main pole, the second material comprised of a spin torque layer, a third material positioned adjacent to the second material on the second side and the third side of the main pole, a fourth material positioned adjacent to the third material on the second side and the third side of the main pole and a side shield connected on an exterior side of the fourth material.

Abstract: An imaging system for an optical element, the imaging system comprising means for illuminating a targeted optical element with at least one incident light beam and means for directing at least two light beams returning from at least one surface of the illuminated optical element onto a detector; the detector adapted to measure relative light characteristics of the at least two returning light beams and to calculate at least one parameter of the optical element using the measured characteristics of the at least two returning light beams.

Abstract: Disclosed herein are magnetic recording devices and methods of using them. A magnetic recording device comprises a main pole extending to an air-bearing surface (ABS), a trailing shield extending to the ABS, a write-field-enhancing structure disposed between and coupled to the main pole and the trailing shield at the ABS, a write coil configured to magnetize the main pole, a write current control circuit coupled to the write coil and configured to apply a write current to the write coil, wherein the write current comprises a write pulse, and a bias current control circuit coupled to the write-field-enhancing structure and configured to apply a bias current to the write-field-enhancing structure, wherein the bias current comprises a driving pulse offset in time from the write pulse by a delay, wherein the delay substantially coincides with an expected magnetization switch-time lag of a free layer of the write-field-enhancing structure.

Abstract: A current-assisted magnetic recording write head has an electrically conductive layer in the write gap between the write pole and the trailing shield. Electrical circuitry directs current between the write pole and the trailing shield, through the conductive layer in the write gap. The current through the conductive layer generates an Ampere field substantially orthogonal to the magnetization in the write pole to assist magnetization switching of the write pole. The conductive layer is wider in the cross-track direction than the trailing edge of the write pole and may extend beyond the write pole side gaps so as to be in contact with both the side shields and the trailing shield. The conductive layer may have substantially the same along-the-track thickness across its width or it may have a thicker central region at the write pole trailing edge and thinner side regions.

Abstract: A microwave-assisted magnetic recording (MAMR) write head has a spin-torque oscillator (STO) and a ferromagnetic compensation layer between the write pole and trailing shield. The compensation layer is separated from a free layer by a nonmagnetic barrier layer that prevents spin-polarized electrons from the free layer from reaching the compensation layer. The compensation layer may be located between the write pole and the free layer. Electrons become spin-polarized by the compensation layer and are reflected back from the write pole across a nonmagnetic spacer layer. This causes the magnetization of the compensation layer to flip and become antiparallel to the magnetization of the free layer. The compensation layer thus generates a DC offset field that compensates for the negative effect of the DC shunting field from the free layer.

Abstract: A microwave assisted magnetic recording (MAMR) write head includes a main pole and a trailing shield. A spin torque oscillator device is disposed between the main pole and the trailing shield. The spin torque oscillator device includes a free layer. A trailing shield hot seed layer is disposed between the spin torque oscillator device and the trailing shield. The trailing shield hot seed layer includes a magnetic material doped with a rare earth element. In certain embodiments, the trailing shield hot seed layer includes the rare earth element in an atomic percent content from about 2% to about 10% atomic percent. In certain embodiments, the trailing shield hot seed layer has an intrinsic damping from about 0.02 to about 0.2.

Abstract: A current-assisted magnetic recording write head has an electrically conductive layer in the write gap between the write pole and the trailing shield. Electrical circuitry directs current between the write pole and the trailing shield, through the conductive layer in the write gap. The current through the conductive layer generates an Ampere field substantially orthogonal to the magnetization in the write pole to assist magnetization switching of the write pole. The conductive layer is wider in the cross-track direction than the trailing edge of the write pole and may extend beyond the write pole side gaps so as to be in contact with both the side shields and the trailing shield. The conductive layer may have substantially the same along-the-track thickness across its width or it may have a thicker central region at the write pole trailing edge and thinner side regions.

Abstract: The present disclosure generally relates to data storage devices, and more specifically, to a magnetic media drive employing a magnetic recording head. The head includes a trailing shield, a main pole, an STO disposed between the trailing shield and the main pole, and a non-magnetic conductive structure adjacent to the main pole and in contact with the STO. The STO includes an FGL and an SPL, and the FGL is disposed between the main pole and the SPL. The FGL includes a side extending over the main pole and at least a portion of the non-magnetic conductive structure. With the FGL disposed proximate to the main pole and over at least a portion of the non-magnetic conductive structure, current crowding and disturbance from the trailing shield are minimized.

Abstract: The present disclosure generally relates to data storage devices, and more specifically, to a magnetic media drive employing a magnetic recording head. The head includes a trailing shield, a main pole, an STO disposed between the trailing shield and the main pole, and a non-magnetic conductive structure adjacent to the main pole and in contact with the STO. The STO includes an FGL and an SPL, and the FGL is disposed between the main pole and the SPL. The FGL includes a side extending over the main pole and at least a portion of the non-magnetic conductive structure. With the FGL disposed proximate to the main pole and over at least a portion of the non-magnetic conductive structure, current crowding and disturbance from the trailing shield are minimized.

Abstract: A microwave assisted magnetic recording (MAMR) write head includes a main pole and a trailing shield. A spin torque oscillator device is disposed between the main pole and the trailing shield. The spin torque oscillator device includes a free layer. A trailing shield hot seed layer is disposed between the spin torque oscillator device and the trailing shield. The trailing shield hot seed layer includes a magnetic material doped with a rare earth element. In certain embodiments, the trailing shield hot seed layer includes the rare earth element in an atomic percent content from about 2% to about 10% atomic percent. In certain embodiments, the trailing shield hot seed layer has an intrinsic damping from about 0.02 to about 0.2.

Abstract: A current-assisted magnetic recording write head has an electrically conductive layer in the write gap between the write pole and the trailing shield. Electrical circuitry directs current between the write pole and the trailing shield, through the conductive layer in the write gap. The current through the conductive layer generates an Ampere field substantially orthogonal to the magnetization in the write pole to assist magnetization switching of the write pole. The conductive layer is wider in the cross-track direction than the trailing edge of the write pole and may extend beyond the write pole side gaps so as to be in contact with both the side shields and the trailing shield. The conductive layer may have substantially the same along-the-track thickness across its width or it may have a thicker central region at the write pole trailing edge and thinner side regions.

Abstract: Disclosed herein are magnetic recording devices and methods of using them. A magnetic recording device comprises a main pole extending to an air-bearing surface (ABS), a trailing shield extending to the ABS, a write-field-enhancing structure disposed between and coupled to the main pole and the trailing shield at the ABS, a write coil configured to magnetize the main pole, a write current control circuit coupled to the write coil and configured to apply a write current to the write coil, wherein the write current comprises a write pulse, and a bias current control circuit coupled to the write-field-enhancing structure and configured to apply a bias current to the write-field-enhancing structure, wherein the bias current comprises a driving pulse offset in time from the write pulse by a delay, wherein the delay substantially coincides with an expected magnetization switch-time lag of a free layer of the write-field-enhancing structure.

Abstract: A write head for a data storage device comprises a main pole, a trailing shield, and a write-field enhancement structure disposed in a write gap between the main pole and the trailing shield. The write-field enhancement structure comprises a non-magnetic spacer, a non-magnetic layer, and a magnetic DC-field-generation (DFG) layer. The DFG layer is sandwiched between the non-magnetic layer and the non-magnetic spacer. The write head also includes at least one magnetic notch adjacent to at least one of the main pole or the trailing shield. The non-magnetic spacer is adjacent to a magnetic notch. Some embodiments include multiple magnetic notches. Also disclosed are data storage devices comprising such write heads.

Abstract: Disclosed herein are perpendicular magnetic recording writers for providing spin-torque-assisted write field enhancement, and hard disk drives comprising such magnetic write heads. A spin-torque-assisting element is disposed in the write gap and extends to the air-bearing surface (ABS). The spin-torque-assisting element comprises a non-magnetic layer in contact with a main pole, a DC-field generation (DFG) layer with a first side in contact with the non-magnetic layer, and a spacer layer in contact with a second side of the DFG layer. A magnetization of the DFG layer is configured to be aligned substantially parallel to a write gap magnetic field generated by the main pole during a write process, and the magnetization of the DFG layer is configured to flip its direction in response to application of a bias current exceeding a specified magnitude.