Planar waveguide for heat assisted magnetic recording

• US 20040062503A1
• Filed: 03/19/2003
• Published: 04/01/2004
• Est. Priority Date: 09/30/2002
• Status: Active Grant

• Current Assignee: Seagate Technology LLC (Seagate Technology Holdings Plc)
• Original Assignee: Seagate Technology LLC (Seagate Technology Holdings Plc)
• Inventors: Challener, William Albert
• Granted Patent: US 7,027,700 B2
• Time in Patent Office: Days
• US Class Current: 385/129
• CPC Class Codes: B82Y 20/00 Nanooptics, e.g. quantum optics or photonic crystals
• CPC Class Codes: G02B 2006/12107 Grating
• CPC Class Codes: G02B 6/1226 involving surface plasmon interaction
• CPC Class Codes: G02B 6/1228 Tapered waveguides, e.g. integrated spot-size transformers for coupling with fibres G02B6/305
• CPC Class Codes: G11B 11/10536 using thermic beams, e.g. lasers
• CPC Class Codes: G11B 2005/0002 Special dispositions or recording techniques
• CPC Class Codes: G11B 2005/0005 Arrangements, methods or circuits
• CPC Class Codes: G11B 2005/0021 Thermally assisted recording using an auxiliary energy source for heating the recording layer locally to assist the magnetization reversal
• CPC Class Codes: G11B 5/012 Recording on, or reproducing or erasing from, magnetic disks G11B17/00, G11B19/00 take precedence
• CPC Class Codes: G11B 5/02 Recording, reproducing, or erasing methods; Read, write or erase circuits therefor
• CPC Class Codes: G11B 5/127 Structure or manufacture of heads, e.g. inductive
• CPC Class Codes: G11B 5/1278 specially adapted for magnetisations perpendicular to the surface of the record carrier
• CPC Class Codes: G11B 5/314 where the layers are extra layers normally not provided in the transducing structure, e.g. optical layers G11B5/3196 takes precedence
• CPC Class Codes: G11B 5/6088 Optical waveguide in or on flying head

Abstract

Recording heads are provided that comprise a magnetic write pole, and a planar waveguide positioned adjacent to the magnetic write pole, the planar waveguide including a first metal layer, a second metal layer, a first optical layer positioned between the first and second metal layers, and means for coupling an electromagnetic wave to the first optical layer at a resonant incident angle. The means for coupling an electromagnetic wave to the first optical layer at a resonant incident angle can comprise a second optical layer positioned adjacent to a surface of the second metal layer opposite the first optical layer and/or a diffraction grating. Means can also be provided for confining the electromagnetic wave in a direction parallel to the plane of the first optical layer. Disc drives incorporating the recording heads and a method of magnetic recording performed by the recording heads are also disclosed.

Claims

1. A recording head comprising:

a magnetic write pole; and

a planar waveguide positioned adjacent to the magnetic write pole, the planar waveguide including a first metal layer, a second metal layer, a first optical layer positioned between the first and second metal layers, and means for coupling an electromagnetic wave to the first optical layer at a resonant incident angle.

2. A recording head according to claim 1, wherein the means for coupling an electromagnetic wave to the first optical layer at a resonant incident angle comprises a second optical layer positioned adjacent to a surface of the second metal layer opposite the first optical layer.

3. A recording head according to claim 1, further comprising:

means for confining the electromagnetic wave in a direction parallel to the plane of the first optical layer.

4. A recording head according to claim 3, wherein means for confining the electromagnetic wave in a direction parallel to the plane of the first optical layer comprises a mode index lens positioned within the first optical layer.

5. A recording head according to claim 3, wherein means for confining the electromagnetic wave in a direction parallel to the plane of the first optical layer comprises an opaque layer positioned at an end of the first optical layer and defining an aperture.

6. A recording head according to claim 1, wherein the first optical layer includes a tapered portion adjacent to an end of the first optical layer.

7. A recording head comprising:

a magnetic write pole; and

a planar waveguide positioned adjacent to the magnetic write pole, the planar waveguide including a first metal layer, a second metal layer, a first optical layer positioned between the first and second metal layers, and a grating positioned on a surface of the first metal layer for coupling an electromagnetic wave into the first optical layer.

8. A recording head according to claim 7, further comprising a second optical layer positioned adjacent to a surface of the second metal layer opposite the first optical layer.

9. A recording head according to claim 7, further comprising:

means for confining the electromagnetic wave in a direction parallel to the plane of the first optical layer.

10. A recording head according to claim 9, wherein means for confining the electromagnetic wave in a direction parallel to the plane of the first optical layer comprises a mode index lens positioned within the first optical layer.

11. A recording head according to claim 9, wherein means for confining the electromagnetic wave in a direction parallel to the plane of the first optical layer comprises an opaque layer positioned at an end of the first optical layer and defining an aperture.

12. A recording head according to claim 7, wherein the first optical layer includes a tapered portion adjacent to an end of the first optical layer.

13. A disc drive comprising:

means for rotating a storage medium; and

means for positioning a recording head adjacent to a surface of the storage medium;

wherein the recording head comprises a magnetic write pole and a planar waveguide positioned adjacent to the magnetic write pole, the planar waveguide including a first metal layer, a second metal layer, a first optical layer positioned between the first and second metal layers, and means for coupling an electromagnetic wave to the first optical layer at a resonant incident angle.

14. A disc drive according to claim 13, wherein the means for coupling an electromagnetic wave to the first optical layer at a resonant incident angle comprises a second optical layer positioned adjacent to a surface of the second metal layer opposite the first optical layer.

15. A disc drive according to claim 13, further comprising:

means for confining the electromagnetic wave in a direction parallel to the plane of the first optical layer.

16. A disc drive according to claim 15, wherein means for confining the electromagnetic wave in a direction parallel to the plane of the first optical layer comprises a mode index lens positioned within the first optical layer.

17. A disc drive according to claim 15, wherein means for confining the electromagnetic wave in a direction parallel to the plane of the first optical layer comprises an opaque layer positioned at an end of the first optical layer and defining an aperture.

18. A disc drive according to claim 13, further comprising:

means for coupling an electromagnetic wave into the first optical layer.

19. A disc drive according to claim 13, wherein the first optical layer includes a tapered portion adjacent to an end of the first optical layer.

20. A disc drive comprising:

means for rotating a storage medium; and

means for positioning a recording head adjacent to a surface of the storage medium;

wherein the recording head comprises a magnetic write pole and a planar waveguide positioned adjacent to the magnetic write pole, the planar waveguide including a first metal layer, a second metal layer, a first optical layer positioned between the first and second metal layers, and a grating positioned on a surface of the first metal layer for coupling an electromagnetic wave into the first optical layer.

21. A disc drive according to claim 20, further comprising a second optical layer positioned adjacent to a surface of the second metal layer opposite the first optical layer.

22. A disc drive according to claim 20, further comprising:

means for confining the electromagnetic wave in a direction parallel to the plane of the first optical layer.

23. A disc drive according to claim 22, wherein means for confining the electromagnetic wave in a direction parallel to the plane of the first optical layer comprises a mode index lens positioned within the first optical layer.

24. A disc drive according to claim 22, wherein means for confining the electromagnetic wave in a direction parallel to the plane of the first optical layer comprises an opaque layer positioned at an end of the first optical layer and defining an aperture.

25. A disc drive according to claim 20, wherein the first optical layer includes a tapered portion adjacent to an end of the first optical layer.

26. A method of magnetic recording comprising:

creating a surface plasmon wave in a waveguide positioned adjacent to a magnetic recording pole;

using the electromagnetic fields from the surface plasmon wave to heat a portion of a recording medium; and

using magnetic flux from the recording pole to change the magnetization of the portion of the recording medium.

27. The method of claim 26, wherein the step of creating a surface plasmon wave in a waveguide comprises:

coupling an electromagnetic wave to a planar waveguide a first metal layer, a second metal layer, and a first optical layer positioned between the first and second metal layers.

28. A planar waveguide comprising:

a first metal layer;

a second metal layer;

a first optical layer positioned between the first and second metal layers; and

means for coupling an electromagnetic wave to the first optical layer at a resonant incident angle.

29. A planar waveguide according to claim 28, wherein the means for coupling an electromagnetic wave to the first optical layer at a resonant incident angle comprises a second optical layer positioned adjacent to a surface of the second metal layer opposite the first optical layer.

30. A planar waveguide according to claim 28, further comprising:

means for confining the electromagnetic wave in a direction parallel to the plane of the first optical layer.

31. A planar waveguide according to claim 30, wherein means for confining the electromagnetic wave in a direction parallel to the plane of the first optical layer comprises a mode index lens positioned within the first optical layer.

32. A planar waveguide according to claim 30, wherein means for confining the electromagnetic wave in a direction parallel to the plane of the first optical layer comprises an opaque layer positioned at an end of the first optical layer and defining an aperture.