According to one embodiment, a magnetic disk device includes a rotatable magnetic disk and a magnetic head including a recording head portion that records data on the magnetic disk. The recording head portion includes a main magnetic pole that applies a recording magnetic field to the magnetic disk, a first yoke provided on a first side of the main magnetic pole and a second yoke provided on a second side of the main magnetic pole, which is opposite to the first side. The magnetic head includes a first heater provided to oppose a side of the first yoke, opposite to the main magnetic pole and a second heater provided to oppose a side of the second yoke, opposite from the main magnetic pole.

According to one embodiment, a disk device includes a disk-shaped recording medium, a base accommodating the recording medium, the base including a bottom wall, a sidewall on a peripheral portion of the bottom wall, and a rib on a part of an upper surface of the sidewall and extending along an entire circumference of the sidewall, a first cover on a part of the upper surface of the sidewall, and a second cover on a first surface of the rib and above the first cover. The rib includes a first region with a first width, a second region with a second width less than the first width, and the first surface with a fixed width around an entire circumference of the rib. The first region and the second region are located corresponding to a side portion of the recording medium.

Described herein are sliders and data storage devices that promote particle mobility to improve particle robustness. In some embodiments, a data storage device includes a recording medium and a slider. A surface of the slider air-bearing surface near the leading edge includes at least one roughening feature that causes the surface to be rougher than other surfaces of the slider to promote particle mobility. The roughening feature may include a regular or irregular pattern, and it may be created using a photoresist mask during the manufacturing process so that the surface is deliberately made rougher (e.g., has a higher friction coefficient) than the surface of a leading pad of the slider.

An apparatus comprises a slider configured for heat-assisted magnetic recording comprising an air bearing surface (ABS). The slider comprises a write pole at or near the ABS, and a near-field transducer (NFT) at or near the ABS and proximate the write pole. A main waveguide is configured to receive light from a laser source and communicate the light to the NFT. An optical power sensor comprises a tap waveguide optically coupled to the main waveguide and comprising a first end and an opposing second end. The optical power sensor also comprises a bolometer optically coupled to the tap waveguide and configured to receive a portion of the light extracted from the main waveguide by the tap waveguide.

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.

A slider design for a hard disk drive (HDD) features an air-bearing surface (ABS) topography with arrays of micro-dots formed on bases of a multiplicity of cavities at different depths. The design eliminates the accumulation of hydrocarbons (e.g., spindle oil and disk lubricant) deposits in regions of air stagnation within the cavities where backflows and foreflows of air meet and cancel during HDD operation. The micro-dots are small raised regions of various shapes having sizes and spacings in the range between 2 and 100 microns and, in a preferred embodiment, heights of 0.15 microns above the cavity bases.

A lumped-parameter function δ is determined that represents an average power dissipated by a write transducer when writing a signal to a magnetic recording medium. Temperatures of the write transducer are measured while varying the parameters to determine constants of the function δ. The function δ is used to adjust power applied to a clearance control heater when writing to the magnetic recording medium.

A magnetic device including: a magnetic reader; a magnetic writer; and a variable overcoat, the variable overcoat positioned over at least the magnetic reader and writer, the variable overcoat having an overcoat layer, the overcoat layer having a substantially constant thickness and material; and at least one disparate overcoat portion, the disparate overcoat portion having a different thickness, a different material, or both, than the overcoat layer.

The present disclosure generally relates to a magnetic media drive employing a magnetic recording head. The magnetic recording head comprises a first write head, a second write head, at least one read head, and a thermal fly height control element. The first write head is a wide writing write head comprising a first main pole and a first trailing shield. The second write head a narrow writing write head comprising a second main pole, a trailing gap, a second trailing shield, and one or more side shields. The first main pole has a shorter height and a greater width than the second main pole. The second main pole has a curved or U-shaped surface disposed adjacent to the trailing gap. The thermal fly height control element and the at least one read head are aligned with a center axis of the second main pole of the second write head.

A data storage device is disclosed comprising a disk, a head for accessing the disk, and a sensor for generating an alternating sensor signal. The sensor is disconnected from an input of a sensing circuit and while the sensor is disconnected an alternating calibration signal is injected into the input of the sensing circuit, wherein the alternating calibration signal comprises a predetermined offset and amplitude. A response of the sensing circuit to the alternating calibration signal is evaluated to detect at least one of an offset and a gain of the sensing circuit.