Thermally assisted recording head with magnetic pole integrated into optical aperture for dual gradient recording
View Patent ↗A write head structure for perpendicular recording having a pole tip integrated into the metal film surrounding a C aperture near field light source is disclosed. The close proximity of the pole tip to the light source enables more precise location of data cells written into the magnetic media, through the use of dual gradient thermally assisted recording. In dual gradient recording, data is fixed by the effect of both a thermal gradient, which affects the coercivity of the magnetic media, combined with a magnetic field gradient imposed by the pole tip.
1. A thin film magnetic head having an integrated optical source comprising:
a write pole, said write pole comprising an upper pole layer, upper pole tip, and upper pole lip;
a near field optical source comprising a conductive metal film, a C aperture fashioned in said conductive metal film, said C aperture comprising a rectangular aperture having a ridge extending into said rectangular aperture from a first portion of said conductive metal film, a second portion of said conductive metal film comprising said upper pole lip, said upper pole lip making up at least a portion of a boundary of said rectangular aperture opposite said ridge; and,
an optical waveguide for illumination of said near field optical source.
2. The apparatus as recited in claim 1 , wherein said thin film magnetic head comprises a backgap magnetically coupled to said write pole, said optical waveguide extending through at least a portion of said backgap.
3. The apparatus as recited in claim 1 , wherein said optical waveguide comprises a light conducting core layer enclosed in cladding layers.
4. The apparatus as recited in claim 3 , wherein said near field optical source has a first surface approximately co-planar with an air bearing surface, said near field optical source having a second surface approximately parallel with said first surface, said second surface opposing said first surface, said light conducting core layer making contact with at least a portion of said second surface.
5. The apparatus as recited in claim 3 , wherein said light conducting core layer comprises tantalum pentoxide.
6. The apparatus as recited in claim 3 , wherein said light conducting core comprises oxides of titanium.
7. The apparatus as recited in claim 1 , wherein said write pole comprises a magnetic step layer, said magnetic step layer contacting said upper pole tip and said upper pole lip.
8. The apparatus as recited in claim 1 , wherein said first portion of said conductive metal film comprises copper.
9. The apparatus as recited in claim 1 , wherein said first portion of said conductive film comprises gold.
10. The apparatus as recited in claim 1 , wherein said second portion of said conductive film comprises a magnetic alloy.
11. The apparatus as recited in claim 10 , wherein said magnetic alloy comprises Co, Ni, and Fe.
12. The apparatus as recited in claim 1 , wherein said C aperture is filled with an optically transparent material.
13. The apparatus as recited in claim 1 , wherein said upper pole lip has a first width, said ridge of said C aperture having a second width, said first width being greater than or equal to said second width.
14. The apparatus as recited in claim 13 , wherein said upper pole tip has a third width, as measured at an air bearing surface, said first width being less than or equal to said third width.
15. The apparatus as recited in claim 14 , wherein said second width is about 16 nanometers, said first width varying between about 20 nanometers and 280 nanometers.
16. The apparatus as recited in claim 15 , wherein a near field heating efficiency varies between about 75% and 90%, when compared to a C aperture having said second portion of said conductive metal film made from gold.
17. A thin film magnetic head having an integrated optical source comprising:
a write pole, said write pole comprising an upper pole layer, upper pole tip, upper pole lip, and a magnetic step layer, said magnetic step layer contacting said upper pole tip and said upper pole lip;
a near field optical source comprising a conductive metal film, a C aperture fashioned in said conductive metal film, said C aperture comprising a rectangular aperture having a ridge extending into said rectangular aperture from a first portion of said conductive metal film, a second portion of said conductive metal film comprising said upper pole lip, said upper pole lip making up at least a portion of a boundary of said rectangular aperture opposite said ridge; and,
an optical waveguide for illumination of said near field optical source.
18. The apparatus as recited in claim 17 , wherein said first portion of said conductive metal film comprises copper.
19. The apparatus as recited in claim 17 , wherein said first portion of said conductive film comprises gold.
20. The apparatus as recited in claim 17 , wherein said second portion of said conductive film comprises a magnetic alloy.