Abstract:
A subwavelength aperture includes a plurality of ridges that project from an aperture sidewall into the aperture opening. The ridges may be closely spaced such that the hot spots associated with the ridges are likewise closely spaced and create an elongated hot spot. The subwavelength aperture of the present invention may be adapted for use in a magnetic head of a hard disk drive for improved thermally assisted recording (TAR) of magnetic data bits. Such a magnetic head may include an optical resonant cavity that is fabricated within the magnetic head structure.
Abstract:
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.
Abstract:
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.
Abstract:
An optical disk data storage system uses an optical disk that has a plurality of substrates, each of which has a data surface. The laser light beam from the system is maintained on the data tracks of a selected one of the spaced-apart data surfaces by the use of tracking marks contained on the data surfaces. The system has a controller that identifies the type of data tracking used on the data surfaces from recorded tracking type information.
Abstract:
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).
Abstract:
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.
Abstract:
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.
Abstract:
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.
Abstract:
A process for forming a plurality of sliders for use in thermally-assisted recording (TAR) disk drives includes a wafer-level process for forming a plurality of aperture structures, and optionally abutting optical channels, on a wafer surface prior to cutting the wafer into individual sliders. The wafer has a generally planar surface arranged into a plurality of rectangularly-shaped regions. In each rectangular region a first metal layer is deposited on the wafer surface, followed by a layer of radiation-transmissive aperture material, which is then lithographically patterned to define the width of the aperture, the aperture width being parallel to the length of the rectangularly-shaped region. A second metal layer is deposited over the patterned layer of aperture material. The resulting structure is then lithographically patterned to define an aperture structure comprising aperture material surrounded by metal and having parallel radiation entrance and exit faces orthogonal to the wafer surface.
Abstract:
A multiple data layer optical medium, such as an optical disk, has a plurality of substrates, each of which has a data surface. The laser light beam from the optical data recording system is maintained on the data tracks of the two spaced-apart data surfaces by the use of tracking marks contained on the data surfaces. One of the data surfaces includes recorded information that identifies the type of tracking marks present.