Heat-assisted recording head having sub wavelength mirror formed of first and second materials
A recording head has a near-field transducer proximate a media-facing surface of the recording head. The near-field transducer extends a first distance away from the media-facing surface. A waveguide overlaps and delivers light to the near-field transducer. Two subwavelength focusing mirrors are at an end of the waveguide proximate the media-facing surface and extend a second distance away from the media-facing surface that is less than the first distance. The subwavelength mirrors are on opposite crosstrack sides of the near-field transducer and separated from each other by a crosstrack gap. The subwavelength focusing mirrors each include a first material at the media-facing surface; and a second material facing away from the media facing surface and in contact with the first material. The second material includes a plasmonic material, and the first material is more mechanically robust than the second material.
1. A recording head comprising:
a near-field transducer proximate a media-facing surface of the recording head, the near-field transducer extending a first distance away from the media-facing surface;
a waveguide that overlaps and delivers light to the near-field transducer; and
a pair of subwavelength focusing mirrors at an end of the waveguide proximate the media-facing surface and extending a second distance away from the media-facing surface that is less than the first distance, the subwavelength mirrors on opposite crosstrack sides of the near-field transducer and separated from each other by a crosstrack gap, the subwavelength focusing mirrors each comprising:
a first material at the media-facing surface; and
a second material facing away from the media facing surface and in contact with the first material, the second material comprising a plasmonic material, the first material more mechanically robust than the second material.
2. The recording head of claim 1 , wherein the subwavelength focusing mirrors each further comprise a liner that covers an edge of the subwavelength focusing mirror that faces the near-field transducer.
3. The recording head of claim 2 , wherein the liner is formed of a material that is more mechanically robust than the second material.
4. The recording head of claim 2 , wherein the liner is formed of the plasmonic material or a second plasmonic material.
5. The recording head of claim 2 , wherein the liner covers both the first and second materials.
6. The recording head of claim 1 , wherein an interface between the first and second materials is parallel to the media-facing surface.
7. The recording head of claim 1 , wherein the first material comprises one of Rh, Ir, Pt, Pd, Ru, or their alloys.
8. The recording head of claim 1 , wherein the first material comprises one of a ceramic material or a magnetic material.
9. The recording head of claim 1 , wherein the second material comprises one of Au, Ag, Cu, Al or their alloys.
10. The recording head of claim 1 , wherein the first material includes a protrusion that extends into the crosstrack gap, the protrusion having a downtrack dimension that is less than that of the subwavelength focusing mirror.
11. The recording head of claim 1 , wherein the first material extends away from the media-facing surface a distance between 50 and 300 nm.
12. A recording head comprising:
a near-field transducer proximate a media-facing surface of the recording head;
a waveguide that overlaps and delivers light to the near-field transducer; and
a pair of subwavelength focusing mirrors at an end of the waveguide proximate the media-facing surface, the subwavelength mirrors on opposite crosstrack sides of the near-field transducer and separated from each other by a crosstrack gap, the subwavelength focusing mirrors each comprising:
a first material at the media-facing surface;
a second material facing away from the media facing surface and in contact with the first material, the second material comprising a plasmonic material, the first material being more mechanically robust than the second material; and
a liner that covers the first and second materials at an edge of the subwavelength focusing mirror that faces the near-field transducer.
13. The recording head of claim 12 , wherein the liner is formed of a material that is more mechanically robust than the second material.
14. The recording head of claim 12 , wherein the liner is formed of the plasmonic material or a second plasmonic material.
15. The recording head of claim 12 , wherein the liner has a thickness between about 1 nm to about 25 nm.
16. A recording head comprising:
a near-field transducer proximate a media-facing surface of the recording head;
a waveguide that overlaps and delivers light to the near-field transducer; and
a pair of subwavelength focusing mirrors at an end of the waveguide proximate the media-facing surface, the subwavelength mirrors on opposite crosstrack sides of the near-field transducer and separated from each other by a crosstrack gap, the subwavelength focusing mirrors each comprising:
a first material at the media-facing surface; and
a second material facing away from the media facing surface and in contact with the first material, the second material comprising a plasmonic material, the first material being more mechanically robust than the second material, the first material includes a protrusion that extends into the crosstrack gap a greater distance than that of the first material.
17. The recording head of claim 16 , wherein the protrusion has a downtrack dimension that is less than that of the subwavelength focusing mirror.
18. The recording head of claim 17 , wherein a downtrack direction of the protrusion is approximately equal to a corresponding downtrack dimension of the near-field transducer, the protrusion being aligned with the near-field transducer in a downtrack direction.
19. The recording head of claim 16 , wherein the subwavelength mirrors each comprise a discontinuity between the first and second materials along an edge that faces the near-field transducer.
20. The recording head of claim 16 , wherein a minimum crosstrack opening between the protrusions of the subwavelength focusing mirrors is less than 100 nm.