Hgst Netherlands, B.v.

Western Digital Technologies, Inc.

Shen Ren

Erhard Theodor Schreck

Barry C Stipe

Takuya Matsumoto

Lidu Huang

John Thomas Contreras

Rehan Ahmed Zakai

Matteo Staffaroni

Seheon Kim

Michael Grobis

Tomoaki Uno

Thomas Dudley Boone, Jr

Hans Juergen Richter

Thomas William Clinton

Barry Cushing Stripe

Embodiments disclosed herein generally relate to a method for monitoring optical power in a HAMR device. In one embodiment, the method includes enhancing a thermal sensor bandwidth through advanced electrical detection techniques. The advanced electrical detection techniques include obtaining calibration waveform data for a thermal sensor by calibrating the thermal sensor, obtaining real-time waveform data for the thermal sensor that may deviate from the calibration waveform data, updating the calibration waveform data to include the real-time waveform data, repeating obtaining real-time waveform data and updating the calibration waveform data during writing operations. By updating the calibration waveform data, the bandwidth of the thermal sensor is determined by a fixed sampling time interval, and the thermal sensor rise time to steady state would not be a limitation to its response time.

HAMR thermal sensor with fast response time

A system, according to one embodiment, includes a magnetic head having: a near field transducer, an optical waveguide for illumination of the near field transducer, and an anti-reflection block positioned along the optical waveguide farther from a media facing side of the magnetic head than the near field transducer. The anti-reflection block is positioned a distance from the near field transducer to destructively interfere with light reflected away from the near field transducer. Other systems, methods, and computer program products are described in additional embodiments.

Anti-reflection waveguide for heat-assisted magnetic recording

A method for annealing a metal antenna of a near field optical transducer of a magnetic write element without inadvertently heat damaging the read element. A heating element is placed within a write head build in a cerf region outside of the active area of the read and write heads. A layer of thermally conductive, electrically insulating material is formed over the heating element to separate the heating element from the antenna. The thermally conductive, electrically insulating layer is preferably in contact with the antenna. A current can be applied to the heating element to heat the antenna to a temperature that is at or above the operating temperature of the optical transducer. After annealing, the heater element can be removed by the lapping process that is used to define the media facing surface of the head.

Near field transducer anneal for heat assisted magnetic recording

In a heat-assisted magnetic recording hard disk drive, a laser module includes a submount-integrated photodetector configured to receive optical energy from a laser by way of a head slider. The submount may be formed of a semiconductor material such as a crystalline silicon material, and the photodetector may be a photodiode that is integrally formed with the submount. A HAMR head slider may comprise a feedback waveguide configured to guide optical energy from the laser through the slider to a feedback photodiode at an interface of the submount and the slider, to detect the optical energy transmitted through the slider to the slider air bearing surface (ABS). A back facet photodiode may also be integrally formed with the submount and configured to receive back facet optical energy to detect the optical energy generated by the laser.

Submount-integrated photodetector for monitoring a laser for a heat-assisted magnetic recording head

Embodiments disclosed herein generally relate to a HAMR device for use in a magnetic reading system. The HAMR device has a primary waveguide extending from a media facing surface to a surface opposite the media facing surface. In one embodiment, the HAMR head has a secondary waveguide having a first and second end positioned within the HAMR head. The secondary waveguide is positioned near the primary waveguide, and the first and second ends of the secondary waveguide are non-reflecting. A thermal sensor is coupled to the secondary waveguide, and responds only to optical power fluctuations in the primary waveguide. In another embodiment, the HAMR head has a second thermal sensor rather than a secondary waveguide. The first thermal sensor and the second thermal sensor are coupled together to act as one optical power sensor and are disposed on the primary waveguide.

Waveguide power sensor structures free of optical coherence effects in a HAMR drive

In one general embodiment, an apparatus includes a write pole, a near field transducer, a waveguide for delivering light to the near field transducer, and a first heating device positioned between the write pole and at least one of the waveguide and the near field transducer.

Combined micro heater and waveguide power sensor for heat-assisted magnetic recording

Embodiments disclosed herein generally relate to a magnetic recording device including slider, a magnetic head assembly and a laser diode having a photodiode integrated therein. The photodiode and the laser diode are both fabricated on a structure. Having the integrated laser diode and photodiode reduces the cost relating to fabricating individual, discrete photodiode and assembling the individual, discrete photodiode on the magnetic recording device.

Photodiode integrated edge emitting laser for heat assisted magnetic recording

Embodiments disclosed herein generally relate to a magnetic write head including a media facing surface and a surface opposite the media facing surface. The magnetic write head also includes a SSC having a first end extending to the surface opposite the media facing surface. The first end of the SSC has at least two tips. The multiple-tipped first end of the SSC is configured to receive a laser beam and the laser beam coupling efficiency is improved by having the multiple-tipped first end.

Spot size converter with a plurality of branches for HAMR heads

Embodiments of the present invention generally relate to a HAMR device having two temperature sensors. The first temperature sensor is disposed adjacent a waveguide and is about two or more micrometers away from an air bearing surface. The first temperature sensor has a length, a width and a thickness, and the length is greater than the width and the thickness. The length of the first temperature sensor is substantially perpendicular to the waveguide.

Dual thermal sensor for HAMR waveguide power monitor and integration with the contact sensor

A method, apparatus, and system for implementing contact sensing are provided using a near field transducer (NFT) and in-drive NFT characterization diagnostics for heat-assisted magnetic recording (HAMR) hard disk drives (HDDs). NFT resistance is monitored and used to determine head to disk contact and spacing. NFT resistance is used to detect NFT head wear.

Implementing contact sensing with near field transducer (NFT) and in-drive NFT characterization diagnostics in heat-assisted magnetic recording (HAMR) HDD

Techniques for improving the recording quality during heat assisted magnetic recording (HAMR) by monitoring the power of a source used to heat a storage medium are described. In one example, a source emits electromagnetic radiation. A waveguide transmits the electromagnetic radiation onto a surface of a magnetic media. A photoresistive material is proximately located to the waveguide. The resistance of the photoresistive material varies based on the intensity of electromagnetic radiation propagating through the waveguide. The power of the source is determined by measuring the resistance of the photoresitive material. The power of the source is adjusted based on the determined power.

Slider embedded photodetector for optical power monitoring in heat assisted magnetic recording

A heat-assisted magnetic recording (HAMR) disk drive with a primary waveguide that directs laser light from a laser diode to a near-field transducer includes a second waveguide for sensing the head-disk spacing or fly-height. The second waveguide has a sensor portion that senses the spacing and directs light representative of the spacing to the second waveguide's output end. The second waveguide may include a second or reference portion that is connected to the sensor portion and directs light representative of light input from the laser diode. The combined light from the two portions is directed to the second waveguide's output end. A detector, which may be a photo-diode, is located at the second waveguide's output end and provides a signal that may be coupled to a thermal fly-height controller to increase or decrease the fly-height.

Heat-assisted magnetic recording (HAMR) disk drive with fly-height sensing

A recessed near field transducer (NFT) in a heat-assisted magnetic recording head is manufactured by applying Joule heating to the slider to induce a protrusion of materials of and around the NFT and, while applying the Joule heating, removing the protrusion by lapping the slider. Removing the induced protrusion in this manner causes the NFT to recess into the body of the slider at ambient temperature, whereby during HAMR operation when optical power is being applied to a disk via the NFT, the NFT is substantially flush with the slider air bearing surface.

Growing community of inventors

Union City, CA, United States of America

Shen Ren