# US 8,787,126 B2 · Waveguide with blocking layer > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,787,126 B2 - Document ID: US8787126B2 - Status: Granted - Kind: B2 - Application number: 13/269,809 - Filed: 2011-10-10 - Published: 2013-04-11 - Granted: 2014-07-22 - Earliest claimed: 2011-10-10 - Assignees: Seagate Technology LLC - Applicants: Nils Jan Gokemeijer; William Albert Challener - Inventors: Nils Jan Gokemeijer; William Albert Challener - Web page: https://patentgrep.com/patent/US8787126B2 ## CPC - G11B 5/314: {where the layers are extra layers normally not provided in the transducing structure, e.g. optical layers (G11B5/3196 takes precedence)} - G11B 5/59638: {Servo formatting apparatuses, e.g. servo-writers} - G11B 2005/0021: {Thermally assisted recording using an auxiliary energy source for heating the recording layer locally to assist the magnetization reversal} - G11B: INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER (recording measured values in a way that does not require playback through a transducer G01D9/00; recording or playback apparatus using mechanically marked tape, e.g. punched paper tape, or using unit records, e.g. punched or magnetically marked cards G06K; transferring data from one type of record carrier to another G06K1/18; circuits for coupling output of reproducer to radio receiver H04B1/20; gramophone pick-ups or like acoustic electromechanical transducers or circuits therefor H04R) ## Abstract An apparatus includes a write pole, a waveguide adjacent to the write pole, the waveguide having a truncated end, and a blocking layer positioned adjacent the truncated end and extending from one side of the waveguide across a portion of an aperture at the truncated end. The waveguide can be a solid immersion mirror or a channel waveguide. ## Claims ### Claim 1 An apparatus comprising: a write pole; a waveguide adjacent to the write pole, the waveguide having a truncated end and an interior surface that converges optical light to a focal point that is axially centered with respect to an aperture at the truncated end; and a blocking layer positioned adjacent the truncated end and extending from a single side of the waveguide across a portion of the aperture at the truncated end to output a non-uniform beam from the waveguide. ### Claim 2 (depends on 1) The apparatus of claim 1, wherein the blocking layer comprises a linear edge that extends across the aperture adjacent the focal point to provide a substantially D-shaped opening for the beam. ### Claim 3 (depends on 1) The apparatus of claim 1, wherein the interior surface is substantially parabolically shaped. ### Claim 4 (depends on 1) The apparatus of claim 1, wherein the planar waveguide includes a core layer having a thickness in the range of about 100 nm to about 1500 nm. ### Claim 5 (depends on 1) The apparatus of claim 1, wherein the waveguide is a channel waveguide. ### Claim 6 (depends on 1) The apparatus of claim 1, wherein an edge of the blocking layer is positioned from a center line of the waveguide at a distance up to one half of the wavelength of light in the waveguide. ### Claim 7 (depends on 1) The apparatus of claim 1, wherein an edge of the blocking layer is positioned from a center line of the waveguide at a distance in the range from 0 nm to about 415 nm. ### Claim 8 (depends on 1) The apparatus of claim 1, wherein a distance between opposing sides of the aperture at the truncated end of the waveguide is in a range from about 120 nm to about 9000 nm. ### Claim 9 (depends on 1) The apparatus of claim 1, wherein the blocking layer has a thickness of about 5 nm to about 50 nm. ### Claim 10 (depends on 1) The apparatus of claim 1, wherein the blocking layer covers less than 180 degrees of the circumferential edge of the aperture. ### Claim 11 An apparatus comprising: a recording medium; a recording head comprising a waveguide adjacent to a write pole and an offset blocking layer positioned adjacent a truncated end of the waveguide and extending from only one side of the waveguide across a portion of an aperture at the truncated end that outputs a beam with a flattened, non-uniform cross-sectional shape onto the recording medium; and a positioning device for positioning the recording head adjacent to the recording medium. ### Claim 12 (depends on 11) The apparatus of claim 11, wherein the waveguide is a planar waveguide having an interior surface shaped to direct an electromagnetic wave to a focal point axially centered in the aperture defined by the truncated end of the waveguide, and the blocking layer extends from a single side of the waveguide to partially cover the aperture to form a substantially D-shaped opening through which the beam passes to the recording medium, wherein the focal point is offset within the aperture. ### Claim 13 (depends on 12) The apparatus of claim 12, wherein the interior surface is substantially parabolically shaped. ### Claim 14 (depends on 12) The apparatus of claim 12, wherein the planar waveguide includes a core layer having a thickness in the range of about 100 nm to about 1500 nm. ### Claim 15 (depends on 11) The apparatus of claim 11, wherein the waveguide is a channel waveguide. ### Claim 16 (depends on 11) The apparatus of claim 11, wherein an edge of the blocking layer is positioned from a center line of the waveguide at a distance up to one half of the wavelength of light in the waveguide. ### Claim 17 An apparatus comprising: a write pole adapted to impart a magnetic field to an adjacent recording medium to write data thereto; and a waveguide adjacent the write pole adapted to impart a flattened, non-circular optical heating beam to the recording medium, the waveguide comprising a non-symmetric opening offset with respect to a central axis of the waveguide along which the beam extends; and an offset blocking layer positioned adjacent the waveguide, the offset blocking layer extending from only one side of the waveguide across a portion of an aperture provided by the waveguide. ### Claim 18 (depends on 17) The apparatus of claim 17, in which the waveguide comprises a body portion with an interior parabolic channel which terminates at the aperture symmetrically about the central axis, and the offset blocking layer affixed to the body portion which partially covers the first aperture to provide a substantially D-shape. ### Claim 19 (depends on 17) The apparatus of claim 17, in which the waveguide comprises a body portion with an interior annular channel with a rectangular cross-sectional shape in a plane perpendicular to the central axis and which terminates at a rectangular aperture with opposing first and second sides and opposing third and fourth sides, and the offset blocking layer which partially covers the respective first and second sides and fully covers the third side, the fourth side remaining uncovered to form the non-symmetric opening. ### Claim 20 (depends on 17) The apparatus of claim 17, characterized as a servo-writer transducer adapted to write a servo pattern to the recording medium to facilitate subsequent positioning of a data transducer adjacent the recording medium.