Trenched near-field transducer for heat assisted magnetic recording
A near-field transducer includes an enlarged transducer portion of plasmonic material extending from an input end to an output end, a surface of the transducer portion including a trench running between two raised portions of the plasmonic material, the trench extending at least partially from the input end to the output end. A peg of the plasmonic material is disposed on the output end of the transducer portion and extends from the output end toward the air bearing surface of a heat assisted magnetic recording slider.
1. A near-field transducer, comprising:
an enlarged transducer portion of plasmonic material extending from an input end to an output end, a surface of the transducer portion including a trench running between two raised portions of the plasmonic material, the trench extending at least partially from the input end to the output end and configured to generate gap-plasmon surface waves; and
a peg of the plasmonic material disposed on and extending from the output end of the transducer portion.
2. The near-field transducer of claim 1 , wherein the peg is aligned with the trench.
3. The near-field transducer of claim 2 , wherein the peg has a width that is substantially equal to a width of the trench.
4. The near field transducer of claim 1 , wherein the trench extends from the input end to the output end.
5. The near-field transducer of claim 1 , wherein the plasmonic material comprises gold.
6. The near-field transducer of claim 1 , wherein the trench is aligned along a centerline of the transducer portion.
7. The near-field transducer of claim 6 , wherein the peg is aligned with the trench.
8. The near-field transducer of claim 7 , wherein the peg is offset from the trench in a direction normal to the surface of the transducer portion.
9. The near-field transducer of claim 1 , wherein the transducer portion has a disc shape.
10. The near-field transducer of claim 1 , wherein the transducer portion has a rectangular shape.
11. A heat assisted magnetic recording head, comprising:
a near field transducer, comprising:
an enlarged transducer portion of plasmonic material extending from an input end to an output end, at least one surface of the transducer portion including a trench disposed between two raised portions of the plasmonic material, the trench extending at least partially from the input end to the output end and dimensioned to generate gap-plasmon surface waves in response to excitation of the near field transducer; and
a peg of the plasmonic material disposed on and extending from the output end of the transducer portion;
a waveguide core configured to deliver light to and excite the near field transducer; and
a magnetic write pole, wherein the near field transducer is disposed between the waveguide core and the magnetic write pole.
12. The magnetic recording head of claim 11 , wherein the NFT displaced from the waveguide core.
13. The magnetic recording head of claim 11 , wherein the peg is offset from the trench in a direction normal to the surface of the transducer portion.
14. The magnetic recording head of claim 11 , wherein the trench extends partially between the input end and the output end.
15. The magnetic recording head of claim 11 , wherein the trench extends fully between the input end and the output end.
16. The magnetic recording head of claim 11 , further comprising a solid immersion mirror configured to focus the light from the waveguide onto the near-field transducer.
17. A method, comprising:
focusing light propagating through a wave guide onto a near-field transducer, the near-field transducer comprising:
an enlarged transducer portion of plasmonic material extending from an input end to an output end, at least one surface of the transducer portion including a trench disposed between two raised portions of the plasmonic material, the trench extending at least partially from the input end to the output end; and
a peg of the plasmonic material disposed on and extending from the output end of the transducer portion;
exciting the near field transducer responsive to the light; and
generating from the trench gap-plasmon surface waves that enhance plasmonic coupling efficiency between the near field transducer and a magnetic media disposed proximate to the near field transducer.
18. The method of claim 17 , wherein focusing the light comprises focusing the light using a solid immersion mirror (SIM).
19. The method of claim 17 , wherein the peg is offset from the trench in a direction normal to the surface of the transducer portion.