Thermally assisted recording of magnetic media using a resonant cavity and energy
View Patent ↗A magnetic head including a media heating device including an optical cavity resonator that produces a high intensity near-field optical beam adjacent to the write pole. 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 proximate an antinode or post within the cavity. The write pole tip may serve as the post in certain embodiments. The media heating device is preferably fabricated between the first and second magnetic pole layers of a perpendicular magnetic head and close to the ABS surface of the head. An alternative embodiment may include a near field aperture disposed between the resonant cavity and the ABS.
1. A magnetic head, comprising:
a write head portion having an air bearing surface thereof;
an optical resonant cavity being disposed entirely within said magnetic head and proximate said air bearing surface;
an optical energy source and an optical energy transmission means to couple optical energy from the source to said resonant cavity;
said resonant cavity including an aperture for directing optical energy from said resonant cavity generally perpendicularly to said air bearing surface.
2. A magnetic head as described in claim 1 wherein said optical energy transmission means includes a waveguide that is disposed apart from and proximate to said resonant cavity.
3. A magnetic head as described in claim 2 wherein said waveguide includes a tapered portion and a narrowed waveguide portion that is disposed proximate said resonant cavity.
4. A magnetic head as described in claim 1 wherein said resonant cavity includes a post that is disposed within said resonant cavity.
5. A magnetic head as described in claim 4 wherein said post includes an end portion that is disposed proximate said aperture.
6. A magnetic head as described in claim 4 wherein said post comprises a write pole of said write head portion of the magnetic head.
7. A magnetic head as described in claim 6 wherein said post has a coating comprised of a nonferrous metal such as silver, gold, aluminum, rhodium, platinum and chromium.
8. A magnetic head as described in claim 4 wherein said post is disposed at a resonant antinode of optical energy within said resonant cavity.
9. A magnetic head as described in claim 4 wherein said post is disposed at a location that is uptrack from said write pole of said write head portion of the magnetic head.
10. A magnetic head as described in claim 1 wherein said resonant cavity is sized for resonance within said cavity at a laser wavelength.
11. A magnetic head as described in claim 1 wherein said aperture has an index of refraction that differs from an index of refraction of the cavity material.
12. A magnetic head as described in claim 1 wherein said resonant cavity is circular cylindrical, having a central axis that is perpendicular to said air bearing surface.
13. A magnetic head as described in claim 12 wherein said resonant cavity includes a post that is disposed along said central axis of said resonant cavity.
14. A magnetic head as described in claim 13 wherein said post is comprised of a nonferrous metal such as silver, gold, aluminum, rhodium, platinum and chromium.
15. A magnetic head as described in claim 1 wherein said aperture is disposed at a location that is uptrack from said write pole of said write head portion of the magnetic head.
16. A magnetic head as described in claim 1 wherein said aperture is formed with a subwavelength dimension compared to the wavelength of optical energy within said resonant cavity.
17. A magnetic head as described in claim 1 wherein said resonant cavity is comprised of a material of relatively higher index of refraction than proximate exterior material and said aperture is comprised of material of index of refraction different from that of the cavity material.
18. A magnetic head as described in claim 1 wherein said resonant cavity is sized for WGM resonance within said cavity at a laser wavelength.
19. A magnetic head as described in claim 1 wherein said resonant cavity is sized for WGM resonance and includes a post disposed at an antinode and parallel to a central axis of said cavity and said post is comprised of a nonferrous metal such as silver, gold, aluminum, rhodium, platinum and chromium.
20. A magnetic head as described in claim 1 wherein dimensions and geometry of said aperture are selected to provide a heating spot having dimensions on the magnetic disk medium that is approximately the same size as data bits formed on said disk medium.
21. A magnetic head as described in claim 1 wherein said write head portion of the magnetic head includes a write pole tip, and said aperture is approximately the same size as said write pole tip.
22. A magnetic head as described in claim 1 wherein said write head portion further includes a near field aperture disposed between said resonant cavity and said air bearing surface.
23. A magnetic head as described in claim 22 wherein said near field aperture includes an opening that is axially aligned with said aperture of said resonant cavity.
24. A magnetic head as described in claim 23 wherein said near field aperture is formed as a thin film comprised of a nonferrous metal.
25. A magnetic head as described in claim 24 wherein said near field aperture is comprised of a metal such as silver, gold, aluminum, rhodium, platinum and chromium.
26. A magnetic head as described in claim 23 wherein said opening is formed in a C or H shape.
27. A magnetic head as described in claim 23 wherein said near field aperture functions as a ridged waveguide.
28. A magnetic head as described in claim 23 wherein said resonant cavity further includes a post that is disposed coaxially with said opening in said near field aperture.
29. A magnetic head as described in claim 1 wherein said optical energy source is disposed within the magnetic head.
30. A hard disk drive, comprising:
at least one hard disk being fabricated for rotary motion upon a disk drive;
at least one magnetic head adapted to fly over said hard disk for writing data on said hard disk, said magnetic head including:
a write head portion having an air bearing surface thereof;
an optical resonant cavity being disposed entirely within said magnetic head and proximate said air bearing surface;
an optical energy source and an optical energy transmission means to couple optical energy from the source to said resonant cavity;
said resonant cavity including an aperture for directing optical energy from said resonant cavity generally perpendicularly to said air bearing surface.
31. A hard disk drive as described in claim 30 wherein said optical energy transmission means includes a waveguide that is disposed apart from and proximate to said resonant cavity.
32. A hard disk drive as described in claim 31 wherein said waveguide includes a tapered portion and a narrowed waveguide portion that is disposed proximate said resonant cavity.
33. A hard disk drive as described in claim 30 wherein said resonant cavity includes a post that is disposed within said resonant cavity.
34. A hard disk drive as described in claim 33 wherein said post comprises a write pole of said write head portion of the magnetic head.
35. A hard disk drive as described in claim 33 wherein said post is disposed at a location that is uptrack from said write pole of said write head portion of the magnetic head.
36. A hard disk drive as described in claim 30 wherein said resonant cavity is circular cylindrical, having a central axis that is perpendicular to said air bearing surface.
37. A hard disk drive as described in claim 30 wherein said aperture is disposed at a location that is uptrack from said write pole of said write head portion of the magnetic head.
38. A hard disk drive as described in claim 30 wherein said write head portion further includes a near field aperture disposed between said resonant cavity and said air bearing surface.
39. A hard disk drive as described in claim 38 wherein said near field aperture includes an opening that is axially aligned with said aperture of said resonant cavity.
40. A hard disk drive as described in claim 38 wherein said near field aperture is formed as a thin film comprised of a nonferrous metal.
41. A hard disk drive as described in claim 38 wherein said near field aperture is comprised of a metal such as silver, gold, aluminum, rhodium, platinum and chromium.
42. A hard disk drive as described in claim 38 wherein said opening is formed in a C or H shape.
43. A hard disk drive as described in claim 38 wherein said near field aperture functions as a ridged waveguide.
44. A hard disk drive as described in claim 38 wherein said resonant cavity further includes a post that is disposed coaxially with said opening in said near field aperture.
45. A hard disk drive as described in claim 30 wherein said optical energy source is disposed within the magnetic head.