Plasmonic coupler used with near-field transducer

Patent metadata

Field	Value
Publication number	US-9934800-B1
Application number	US-201715435583-A
Country	US
Kind code	B1
Filing date	Feb 17, 2017
Priority date	Feb 29, 2016
Publication date	Apr 3, 2018
Grant date	Apr 3, 2018

Abstract

A waveguide has a first cladding layer surrounding a near-field transducer. A core of the waveguide is disposed on the first cladding layer, and a second cladding layer is disposed on the core opposite the first cladding layer. A coupler is formed of a second plasmonic material and disposed in the waveguide such that a first edge of the coupler is proximate a media-facing surface and a first side of the coupler faces and is spaced apart from a peg of the near-field transducer in a downtrack direction.

First claim

What is claimed is:

1. An apparatus, comprising:
a near-field transducer comprising an enlarged portion formed of a plasmonic material and a peg extending from the enlarged portion towards a media-facing surface of the read/write head;
a waveguide comprising a first cladding layer surrounding the near-field transducer, a core disposed on the first cladding layer, and a second cladding layer disposed on the core opposite the first cladding layer;
a coupler formed of a second plasmonic material and disposed in the waveguide such that a first edge of the coupler is proximate the media-facing surface and a first side of the coupler faces and is spaced apart from the peg of the near-field transducer in a downtrack direction; and
an optical shield extending from the first side of the coupler at the first edge and extending into the core towards the peg, the optical shield formed of the second plasmonic material, a gap between the optical shield and the peg of the near-field transducer creating a gap plasmon mode.

2. The apparatus of claim 1 , further comprising a leading magnetic shield proximate a second side of the coupler that faces away from the first side.

3. The apparatus of claim 1 , wherein the coupler is located in the second cladding layer.

4. The apparatus of claim 1 , wherein a tip of the optical shield comprises a different material than the second plasmonic material, the different material comprising one of Rh, Pt, Pd, and Ru.

5. The apparatus of claim 1 , wherein the first plasmonic material is the same as the second plasmonic material.

6. The apparatus of claim 1 , wherein the coupler comprises a second, rounded edge facing away from the first edge, the first edge comprising a rectangular shape, and wherein the enlarged portion of the near-field transducer comprises a stadium shape.

7. The apparatus of claim 1 , wherein the peg is made of a different material than the enlarged portion of the near-field transducer.

8. The apparatus of claim 1 , wherein the coupler comprises first and second triangular portions with edges facing the near-field transducer at a non-zero angle relative to the media facing surface.

9. The apparatus of claim 8 , wherein the coupler comprises a downtrack thickness at a minimum near the peg, the downtrack thickness increasing away from the peg in a crosstrack direction.

10. An apparatus comprising:
a near-field transducer comprising a plate-like enlarged portion disposed on a first substrate parallel plane and a peg extending from the enlarged portion towards a media-facing surface;
a plasmonic coupler separate from the near-field transducer on a second substrate parallel plane, the plasmonic coupler comprising two triangular sections separated by a gap, the two triangular sections comprising sides facing the near-field transducer at a non-zero angle relative to the media facing surface, the enlarged portion of the near-field transducer overlapping the gap, the two triangular sections joined underneath the peg of the near-field transducer such that the plasmonic coupler guides light from the waveguide to set up an electric field that interferes with a corresponding field excited by the peg of the near-field transducer, the interference with the corresponding field sharpening the corresponding electric field of the peg; and
a waveguide that delivers the light to the near-field transducer and the plasmonic coupler.

11. The apparatus of claim 10 , wherein the plasmonic coupler comprises a downtrack thickness at a minimum near the peg, the downtrack thickness increasing away from the peg in a crosstrack direction.

12. An apparatus, comprising:
a near-field transducer comprising an enlarged portion formed of a plasmonic material and a peg extending from the enlarged portion towards a media-facing surface of the read/write head;
a waveguide comprising a first cladding layer surrounding the near-field transducer, a core disposed on the first cladding layer, and a second cladding layer disposed on the core opposite the first cladding layer;
a coupler formed of a second plasmonic material and disposed in the second cladding layer such that a first edge of the coupler is proximate the media-facing surface and first side of the coupler faces and is spaced apart from the peg of the near-field transducer in a downtrack direction, the coupler overlapping the enlarged portion of the near-field transducer, wherein the coupler comprises a second, rounded edge facing away from the first edge, the first edge comprising a rectangular shape, and wherein the enlarged portion of the near-field transducer comprises a stadium shape; and
a leading magnetic shield proximate a second side of the coupler that faces away from the first side.

13. The apparatus of claim 12 , further comprising an optical shield extending from the first side of the coupler at the first edge and extending into the core towards the peg, the optical shield formed of the second plasmonic material, a gap between the optical shield and the peg of the near-field transducer creating a gap plasmon mode.

14. The apparatus of claim 13 , wherein a tip of the optical shield comprises a different material than the second plasmonic material, the different material comprising one of Rh, Pt, Pd, and Ru.

15. The apparatus of claim 13 , wherein the optical shield comprises a wedge shape with a narrower portion proximate the peg and a wider portion proximate the coupler.

16. The apparatus of claim 12 , wherein the first plasmonic material is the same as the second plasmonic material.

17. The apparatus of claim 12 , wherein the peg is made of a different material than the enlarged portion of the near-field transducer.

18. The apparatus of claim 10 , wherein the waveguide delivers the light in a TE 10 mode such that a main component of an electric field of the light is in a substrate parallel plane, such that surface plastrons are coupled from the plasmonic coupler to the peg in a direction normal to the substrate parallel plane.

Assignees

• Seagate Technology Llc

Inventors

• Neira Andres David Barbosa
• Garcia Roberto Fernandez
• Hardy Michael James
• Gubbins Mark Anthony
• Blaber Martin Giles

Classifications

• G11B2005/0021

  Thermally assisted recording using an auxiliary energy source for heating the recording layer locally to assist the magnetization reversal · CPC title

• G11B7/126

  Circuits, methods or arrangements for laser control or stabilisation · CPC title

• G11B11/1051

  by modulating both the magnetic field and the light beam at the transducers · CPC title

• G11B11/10506

  by modulating only the light beam of the transducer · CPC title

• G11B5/6088 Primary

  Optical waveguide in or on flying head · CPC title