Near-field light generator and thermally-assisted magnetic recording head
A near-field light generator includes a plasmon generator including a plasmon exciting portion on which a surface plasmon is excited, and a near-field transducer including a front end face that generates near-field light from the surface plasmon. The near-field transducer is formed of a first metal material. The plasmon generator includes a first portion formed of the first metal material and a second portion formed of a second metal material. The first portion is in contact with the near-field transducer. The second portion includes at least part of the plasmon exciting portion.
1. A near-field light generator comprising:
a plasmon generator including a plasmon exciting portion on which a surface plasmon is excited; and
a near-field transducer including a front end face that generates near-field light from the surface plasmon, wherein
the near-field transducer is formed of a first metal material,
the plasmon generator includes a first portion formed of the first metal material and a second portion formed of a second metal material,
the first portion is in contact with the near-field transducer, and the second portion includes at least part of the plasmon exciting portion.
2. The near-field light generator according to claim 1 , wherein the second portion is not in contact with the near-field transducer.
3. The near-field light generator according to claim 1 , wherein the second portion is in contact with the near-field transducer.
4. The near-field light generator according to claim 3 , wherein:
the near-field transducer includes a front portion and a rear portion located farther from the front end face than the front portion is;
the first portion of the plasmon generator is in contact with the front portion of the near-field transducer; and
the second portion of the plasmon generator is in contact with the rear portion of the near-field transducer.
5. The near-field light generator according to claim 1 , wherein the plasmon generator is a planar plasmon generator.
6. The near-field light generator according to claim 1 , wherein:
the first metal material is a PtAu alloy; and
the second metal material is Au.
7. The near-field light generator according to claim 6 , wherein the PtAu alloy has a Pt content of 75 wt % or more and not more than 99 wt %.
8. A thermally-assisted magnetic recording head comprising:
a medium facing surface that faces a recording medium;
a main pole that generates a recording magnetic field for recording information on the recording medium;
a waveguide including a core that propagates light and a cladding that is located around the core; and
the near-field light generator according to claim 1 , wherein
the front end face of the near-field transducer is located in the medium facing surface.
9. The thermally-assisted magnetic recording head according to claim 8 , wherein:
the core includes an evanescent light generating surface that generates evanescent light from the light propagating through the core; and
the surface plasmon is excited on the plasmon exciting portion of the plasmon generator through coupling with the evanescent light.
10. The thermally-assisted magnetic recording head according to claim 8 , wherein the plasmon generator includes an end that is closest to the medium facing surface and located at a distance from the medium facing surface.
11. The thermally-assisted magnetic recording head according to claim 8 , wherein the second portion is not in contact with the near-field transducer.
12. The thermally-assisted magnetic recording head according to claim 8 , wherein the second portion is in contact with the near-field transducer.
13. The thermally-assisted magnetic recording head according to claim 12 , wherein:
the near-field transducer includes a front portion and a rear portion located farther from the front end face than the front portion is;
the first portion of the plasmon generator is in contact with the front portion of the near-field transducer; and
the second portion of the plasmon generator is in contact with the rear portion of the near-field transducer.
14. The thermally-assisted magnetic recording head according to claim 8 , wherein the plasmon generator is a planar plasmon generator.
15. The thermally-assisted magnetic recording head according to claim 8 , wherein:
the first metal material is a PtAu alloy; and
the second metal material is Au.
16. The thermally-assisted magnetic recording head according to claim 15 , wherein the PtAu alloy has a Pt content of 75 wt % or more and not more than 99 wt %.