Near-field light generator including a plasmon generator and a waveguide
View Patent ↗A near-field light generator includes a waveguide, a plasmon generator, and an MgO layer. The waveguide includes a core and a cladding. The plasmon generator has an outer surface including a plasmon exciting part and a near-field light generating part, and is configured so that a surface plasmon is excited on the plasmon exciting part based on light propagating through the core, and the near-field light generating part generates near-field light based on the surface plasmon. The MgO layer is in contact with at least part of the outer surface of the plasmon generator excluding the near-field light generating part, and not in contact with the core. The cladding is lower in refractive index than the core and the MgO layer.
1. A near-field light generator comprising a waveguide, a plasmon generator, and an MgO layer, wherein
the waveguide includes a core through which light propagates, and a cladding,
the plasmon generator has an outer surface including a plasmon exciting part and a near-field light generating part, and is configured so that a surface plasmon is excited on the plasmon exciting part based on the light propagating through the core, and the near-field light generating part generates near-field light based on the surface plasmon,
the MgO layer is in contact with at least part of the outer surface of the plasmon generator excluding the near-field light generating part, and not in contact with the core, and
the cladding is lower in refractive index than the core and the MgO layer.
2. The near-field light generator according to claim 1 , wherein the cladding has an interposition part interposed between the core and the plasmon generator.
3. The near-field light generator according to claim 2 , wherein
the core has an evanescent light generating surface that generates evanescent light based on the light propagating through the core,
the plasmon exciting part is opposed to the evanescent light generating surface with the interposition part interposed therebetween, and
the surface plasmon is excited on the plasmon exciting part through coupling with the evanescent light generated by the evanescent light generating surface.
4. The near-field light generator according to claim 2 , wherein at least part of the MgO layer is interposed between the interposition part and the plasmon generator.
5. A thermally-assisted magnetic recording head comprising:
a medium facing surface that faces a magnetic recording medium;
a magnetic pole having an end face located in the medium facing surface, the magnetic pole producing a write magnetic field for writing data on the magnetic recording medium;
a waveguide;
a plasmon generator; and
an MgO layer, wherein
the waveguide includes a core through which light propagates, and a cladding,
the plasmon generator has an outer surface including a plasmon exciting part and a near-field light generating part, and is configured so that a surface plasmon is excited on the plasmon exciting part based on the light propagating through the core, and the near-field light generating part generates near-field light based on the surface plasmon,
the MgO layer is in contact with at least part of the outer surface of the plasmon generator excluding the near-field light generating part, and not in contact with the core, and
the cladding is lower in refractive index than the core and the MgO layer.
6. The thermally-assisted magnetic recording head according to claim 5 , wherein the cladding has an interposition part interposed between the core and the plasmon generator.
7. The thermally-assisted magnetic recording head according to claim 6 , wherein
the core has an evanescent light generating surface that generates evanescent light based on the light propagating through the core,
the plasmon exciting part is opposed to the evanescent light generating surface with the interposition part interposed therebetween, and
the surface plasmon is excited on the plasmon exciting part through coupling with the evanescent light generated by the evanescent light generating surface.
8. The thermally-assisted magnetic recording head according to claim 6 , wherein at least part of the MgO layer is interposed between the interposition part and the plasmon generator.
9. A head gimbal assembly comprising: the thermally-assisted magnetic recording head according to claim 5 ; and a suspension that supports the thermally-assisted magnetic recording head.
10. A magnetic recording device comprising: a magnetic recording medium; the thermally-assisted magnetic recording head according to claim 5 ; and a positioning device that supports the thermally-assisted magnetic recording head and positions the thermally-assisted magnetic recording head with respect to the magnetic recording medium.