Near-field transducer with a dielectric slit at internal surfaces for controlling feedback to a light source

Patent metadata

Field	Value
Publication number	US-10283152-B1
Application number	US-201816006324-A
Country	US
Kind code	B1
Filing date	Jun 12, 2018
Priority date	Jun 16, 2017
Publication date	May 7, 2019
Grant date	May 7, 2019

Abstract

A recording head includes a waveguide configured to deliver light from a light source to a media-facing surface of the recording head. A near-field transducer is at the media-facing surface the proximate the waveguide. The near-field transducer includes a plasmonic structure with at least two opposing internal surfaces. A dielectric material fills a region between the at least two opposing internal surfaces. A dielectric slit extends between the at least two opposing internal surfaces. The dielectric slit is substantially parallel to the media-facing surface and includes a transparent material with a refractive index different than that of the dielectric material.

First claim

What is claimed is:

1. A recording head comprising:
a waveguide configured to deliver light from a light source to a media-facing surface of the recording head;
a near-field transducer at the media-facing surface the proximate the waveguide, the near-field transducer comprising a plasmonic structure with at least two opposing internal surfaces, a dielectric material filling a region between the at least two opposing internal surfaces; and
a dielectric slit extending between the at least two opposing internal surfaces, the dielectric slit substantially parallel to the media-facing surface and comprising a transparent material with a refractive index different than that of the dielectric material.

2. The recording head of claim 1 , wherein the dielectric slit reduces feedback of the light to the light source.

3. The recording head of claim 2 , wherein an input surface of the slider proximate the light source is anti-reflection coated.

4. The recording head of claim 1 , wherein the dielectric slit increases feedback of the light to the light source, causing the light source to operate in an external cavity mode.

5. The recording head of claim 4 , wherein a front facet of the light source and an input surface of the slider comprise an anti-reflective coating.

6. The recording head of claim 1 , wherein the near-field transducer comprises an aperture extending from the waveguide to the media-facing surface, the at least two opposing sides comprising sides of the aperture.

7. The recording head of claim 6 , wherein the aperture comprises a funnel shape that decreases in cross-sectional area towards the media facing surface.

8. The recording head of claim 6 , wherein the aperture comprises one of an E-shape and a C-shape.

9. The recording head of claim 1 , wherein the near-field transducer comprises two substrate-parallel plates with a gap therebetween, the at least two opposing sides comprising edges of the plates that form the gap.

10. The recording head of claim 1 , wherein the dielectric material comprises a core material of the waveguide, and wherein the refractive index of the dielectric slit is less than that of the core material.

11. A recording head comprising:
a waveguide configured to deliver light from a light source to a media-facing surface of the recording head;
a near-field transducer at the media-facing surface the proximate the waveguide, the near-field transducer comprising a plasmonic structure surrounding an aperture that is filled with a dielectric material, an internal wall of the aperture comprising a structure with two surfaces substantially parallel to the media-facing surface, the structure controlling reflection of the light back to the light source.

12. The recording head of claim 11 , wherein the structure reduces the feedback.

13. The recording head of claim 11 , wherein the structure increases the feedback, causing the light source to operate in an external cavity mode.

14. The recording head of claim 11 , wherein the structure comprises a ridge extends from the internal wall into the aperture.

15. The recording head of claim 11 , wherein the structure comprises a cavity extends into the internal wall and results in a local increase in a width of the aperture.

16. The recording head of claim 11 , wherein the aperture comprises a funnel shape that decreases in cross-sectional area towards the media facing surface.

17. The recording head of claim 11 , where the near-field transducer is asymmetric with the two opposing sides having different height from the media-facing surface.

18. A recording head, comprising:
a waveguide configured to deliver light from a light source to a media-facing surface of the recording head;
a near-field transducer at the media-facing surface the proximate the waveguide, the near-field transducer comprising a plasmonic structure surrounding an aperture, a dielectric material filling the aperture; and
a dielectric slit extending between at least two opposing internal surfaces of the aperture, the dielectric slit substantially parallel to the media-facing surface and comprising a transparent material with a refractive index different than that of the dielectric material, the dielectric slit reducing feedback of the light to the light source.

19. The recording head of claim 18 , wherein the aperture comprises a tunnel shape that decreases in cross-sectional area towards the media facing surface.

20. The recording head of claim 1 , wherein the dielectric material comprises a core material of the waveguide, and wherein the refractive index of the dielectric slit is less than that of the core material.

Assignees

• Seagate Technology Llc

Inventors

• Peng Chubing
• Wessel James Gary
• Lee Lien

Classifications

• G11B11/24

  using recording by near-field interactions · CPC title

• G11B5/6088

  Optical waveguide in or on flying head · CPC title

• G11B13/08

  using near-field interactions or transducing means and at least one other method or means for recording or reproducing · CPC title

• G11B7/12

  Heads, e.g. forming of the optical beam spot or modulation of the optical beam (disposition or mounting of head elements within housing or with provision for moving of light source, optical beam or detector, irrelevant to the transducing method G11B7/08 {; modulating lasers H01S3/10; controlling the intensity, colour, phase, polarisation or direction of light beams arriving from an independent light source, e.g. switching gating or modulating G02F1/00}) · CPC title

• G11B2005/0021

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