International Business Machines Corporation

Hitachi Global Storage Technologies Netherlands B.v.

Hgst Netherlands, B.v.

Timothy Carl Strand

Hal Jervis Rosen

Kurt A Rubin

Margaret E Best

Barry C Stipe

Chie Ching Poon

Thomas Dudley Boone, Jr

Toshiki Hirano

Wayne Isami Imaino

Milton Russell Latta

Blair I Finkelstein

Jia-Yang Juang

Neil Leslie Robertson

James M Zavislan

Bruce David Terris

Henry Hung Yang

Timothy C Reiley

Hamid Balamane

James Terrence Olson

Wai Cheung Leung

Petrus Antonius VanDerHeijden

Terry W McDaniel

Andrew A Gaudet

Xuhui Jin

Hendrik F Hamann

Robert Fontana

Yimin Hsu

Andrew Ching Tam

Fu-Ying Huang

Peter Michael Baumgart

Tim Minvielle

David W Albrecht

Karl Arthur Flechsig

Glenn T Sincerbox

Gurinder P Singh

Anthony Juliana

James Hammond Brannon

Bob Clyde Robinson

Wade Wai-Chung Tang

Wade W-c Tang

Iraj Kakesh Pour

Hal A Rosen

Victor T Pan

An apparatus according to one embodiment includes a near field transducer comprising a conductive metal film; and an optical waveguide for illumination of the near field transducer, a light guiding core layer of the optical waveguide being spaced from the near field transducer by less than about 100 nanometers and greater than 0 nanometers, wherein a longitudinal axis of the optical waveguide is substantially perpendicular to an air bearing surface.

Thermally assisted recording head having recessed waveguide with near field transducer and methods of making same

A device for detecting disk asperities. The device includes an optical glide head. The glide head is not required to physically contact a disk for detection of the disk asperities. The optical glide head includes a waveguide configured to transmit light onto the disk and receive reflected light from the disk.

Contactless optical glide head using at least two concurrent interference signals and a multi-channel light detector for detecting disk asperities

A thermally-assisted recording (TAR) disk drive uses 'shingled' recording and a rectangular waveguide as a 'wide-area' heat source. The waveguide generates a generally elliptically-shaped optical spot that heats an area of the recording layer extending across multiple data tracks. The waveguide core has an aspect ratio (cross-track width to along-the track thickness) that achieves the desired size of the heated area while locating the peak optical intensity close to the trailing edge of the write pole tip where writing occurs. The large cross-track width of the waveguide core increases the volume of recording layer heated by the optical spot, which reduces the rate of cooling. This moves the peak temperature point of the heated area closer to the write pole tip and reduces the temperature drop between the peak temperature and the temperature at the trailing edge of the write pole tip where writing occurs.

Magnetic recording disk drive with shingled writing and rectangular optical waveguide for wide-area thermal assistance

An apparatus, system, and method for measuring thermally induced electric resistance changes in thermally assisted magnetic recording are disclosed for monitoring laser light output in thermally assisted magnetic recording disk drives. An electrical lead is coupled to a read/write head element. A first electrical resistance in the read/write head element is measured. The read/write head is heated by a laser and a second electrical resistance in the read/write head element is measured. The electrical resistance may be monitored at regular intervals when the read/write head element is on the ramp or the electrical resistance measurements may be continuously monitored as the read/write head flies over the magnetic media.

Laser power sensor for thermally assisted magnetic recording

A laser, such as a horizontal cavity surface emitting laser, with internal polarization rotation may be used in thermally assisted recording in hard disk drives. The desired polarization of the laser may be accomplished with two beam reflections off of facets within the laser. The facets may be formed in a single ion beam etching step. The laser may be used on a thermally assisted recording head to produce a polarized beam that is aligned with a track direction of the disk.

System, method and apparatus for internal polarization rotation for horizontal cavity, surface emitting laser beam for thermally assisted recording in disk drive

A thermally-assisted recording (TAR) disk drive uses a 'wide-area' heater with 'shingled' recording. In shingled recording, the write head pole tip is wider than the read head in the cross-track direction and writes magnetic transitions by making a plurality of consecutive circular paths that partially overlap. The non-overlapped portions of adjacent paths form the data tracks, which are thus narrower than the width of the write pole tip. The data tracks are grouped into annular bands and when data is to be rewritten, all of the data tracks in an annular band are also rewritten. The wide-area heater may be a waveguide with an output end that generates a heated area on the disk recording layer which is wider than the cross-track width of the write pole tip. It has been determined that the use of a wide-area heater with shingled recording does not result in any significant adjacent track erasure (ATE).

Magnetic recording disk drive with shingled writing and wide-area thermal assistance

A horizontal cavity, surface emitting laser (HCSEL) with internal polarization rotation is used in thermally assisted recording in hard disk drives. The desired polarization of the laser is accomplished with two beam reflections off of facets within the diode. The facets are formed in a single ion beam etching step. This device can be used in a thermally assisted recording head to produce polarization incident on the disk aligned with the direction of the tracks on the disk.

A thermally-assisted recording (TAR) slider has an integrated TAR head and an integrated long laser diode, like an external-cavity VCSEL. The TAR head is integrated with the slider at the trailing end and includes an optical waveguide having a grating coupler oriented in a plane generally parallel to the slider trailing end, and a near-field transducer (NFT) at the slider air-bearing surface (ABS) and coupled to the waveguide. A carrier is attached to the slider front end and supports the external-cavity VCSEL so that the linear path of its output laser beam is directed from the slider front end to the slider trailing end. An optical body is attached to the slider trailing end and has an input surface for receipt of the laser radiation from the laser diode, an output surface for directing the laser radiation to the grating coupler, and at least one reflective surface for turning the laser radiation from the input surface to the output surface.

Slider with integrated thermally-assisted recording (TAR) head and long laser diode with optical body for directing laser radiation

According to one embodiment, an apparatus includes a near field transducer comprising a conductive metal film having a main body and a ridge extending from the main body and an optical waveguide for illumination of the near field transducer, a light guiding core layer of the optical waveguide being spaced from the near field transducer by less than about 100 nanometers and greater than 0 nanometers. In another embodiment, a method includes forming a near field transducer structure and removing a portion of the near field transducer structure. The method also includes forming a cladding layer adjacent a remaining portion of the near field transducer structure, wherein a portion of the cladding layer extends along the remaining portion of the near field transducer structure and forming a core layer above the cladding layer. Other apparatuses and methods are also included in the invention.

A thermally-assisted recording (TAR) slider has an integrated TAR head and an integrated external-cavity VCSEL. The TAR head is integrated with the slider at the trailing end and includes an optical waveguide having a grating coupler oriented in a plane generally parallel to the slider trailing end, and a near-field transducer (NFT) at the slider air-bearing surface (ABS) and coupled to the waveguide. The external cavity is an angled structure and has an input surface for receipt of laser radiation output from the VCSEL, an output surface near the slider trailing end, a partially reflecting third mirror near the output surface, and at least one reflective surface between the input surface and the third mirror for turning the laser radiation and reflecting it between the VCSEL and the third mirror. The laser radiation is output from the external cavity's output surface, through the trailing end of the slider and to the grating coupler.

Slider with integrated thermally-assisted recording (TAR) head and vertical-cavity surface-emitting laser (VCSEL) with angled external cavity

A thermally-assisted recording (TAR) slider has an integrated TAR head and an integrated laser diode. The laser diode may be an external-cavity VCSEL that includes a semiconductor substrate with the VCSEL formed on one surface, an external cavity on the opposite surface, and an output third mirror on the output surface of the external cavity. The TAR head is integrated with the slider at the trailing end and includes an optical waveguide having a grating coupler oriented in a plane generally parallel to the slider trailing end, and a near-field transducer (NFT) at the slider air-bearing surface (ABS) and coupled to the waveguide. A carrier is attached to the slider and has a base portion that supports the external-cavity VCSEL so that the linear path of its output laser beam is aligned with and oriented orthogonal to the plane of the grating coupler. The grating coupler receives the laser radiation and turns it 90 degrees into the waveguide, which directs the laser radiation to the NFT at the ABS.

Slider with integrated thermally-assisted recording (TAR) head and integrated long laser diode

A thermally-assisted perpendicular magnetic recording head and system has a head carrier that supports an optical channel for the transmission of radiation to the recording layer, a write pole for directing a magnetic field to the recording layer, and an electrical coil for inducing the magnetic field from the write pole. The optical channel has a radiation exit face with an aperture at the recording-layer-facing surface of the head carrier. The write pole has a pole tip with an end face that is recessed from the recording-layer-facing surface. The write pole tip is tapered down to the end faces. The pole tip taper and the recession of the end face concentrates the write field at the middle of the perpendicular magnetic recording layer where the radiation from the optical channel is incident. The characteristic dimension of the aperture and the spacing between the aperture and the recording layer are both less than the wavelength of the radiation. The radiation source may be a laser diode mounted to the head carrier.

Thermally-assisted perpendicular magnetic recording system with write pole surrounding an optical channel and having recessed pole tip

Methods and devices for generating multiple, closely spaced, independently controlled near-field light sources are disclosed. By providing an aperture having at least two, orthogonally oriented ridge structures, two or more closely spaced near-field light sources can be generated by controlling the polarization direction of the illuminating radiation. Control of the shape of the aperture, and relative dimensions of the ridge structures allows optimization of the relative intensities of the near-field sources.

Method and apparatus for the generation and control of multiple near-field light sources at subwavelength resolution

The media heating device of the magnetic head includes an optical resonant cavity produces a high intensity near-field optical beam of subwavelength dimension adjacent to the write pole. A suitable resonant cavity may be a spherical cavity, disk shaped cavity, ring shaped cavity, racetrack shaped cavity, micropillar cavity, photonic crystal cavity and Fabry-Perot cavity. The cavity is fabricated as a planar thin film structure in layers that are generally parallel to the magnetic pole thin film layers of the magnetic head, such that the principal axis of the resonant cavity is parallel to the air bearing surface (ABS). Optical energy is coupled into the resonant cavity through a waveguide that is placed proximate the cavity, and optical energy is coupled out of the cavity through an aperture that is placed within the cavity. A preferred embodiment may include a nano-aperture disposed between the resonant cavity and the ABS.

Thermally assisted recording of magnetic media using an optical resonant cavity

The media heating device of the magnetic head includes an optical resonant cavity and a nano-pin that produces a high intensity near-field optical beam of sub-wavelength dimension adjacent to the write pole. The cavity is fabricated as a planar thin film structure in layers that are generally parallel to the magnetic pole thin film layers of the magnetic head, such that a principal axis of the resonant cavity is parallel to the air bearing surface (ABS). Optical energy is coupled into the resonant cavity through a waveguide that is placed proximate the cavity, and optical energy is coupled out of the cavity through a nano-pin that is disposed between the resonant cavity and the ABS.

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San Jose, CA, United States of America

Timothy Carl Strand