Laser feedback suppressor for heat-assisted magnetic recording

Patent metadata

Field	Value
Publication number	US-12106771-B2
Application number	US-202318371146-A
Country	US
Kind code	B2
Filing date	Sep 21, 2023
Priority date	Oct 31, 2019
Publication date	Oct 1, 2024
Grant date	Oct 1, 2024

Abstract

A recording head includes a channel waveguide that delivers light to a media-facing surface. A near-field transducer (NFT) is at an end of the channel waveguide and proximate to the media-facing surface. A laser including an active region has a longitudinal axis corresponding to a propagation direction of the channel waveguide. The active region includes a back facet and a front facet proximate the NFT. The front facet has a surface shape configured to suppress back reflection of the light.

First claim

What is claimed is:

1. A recording head, comprising:
a channel waveguide that delivers light to a media-facing surface;
a near-field transducer (NFT) at an end of the channel waveguide and proximate to the media-facing surface; and
a laser comprising an active region formed of a non-self supporting, crystalline layer transfer printed to a substrate, the active region having a longitudinal axis corresponding to a propagation direction of the channel waveguide, the active region comprising a back facet and a front facet proximate the NFT, the front facet having a surface shape configured to suppress back reflection of the light, the surface shape of the front facet comprising one or both of a convex shape and a concave shape.

2. The recording head of claim 1 , wherein one or both of the convex shape and the concave shape is off centered with respect to the longitudinal axis.

3. The recording head of claim 1 , wherein the surface shape is configured to allow forward light transmission and reduce feedback.

4. The recording head of claim 1 , wherein the surface shape of the front facet is configured to suppress an amount of feedback in the range of about 20% to about 30%.

5. The recording head of claim 1 , wherein:
one or both of the convex shape and the concave shape comprises one or both of a vertical angle and a lateral angle; and
the one or both of the vertical angle and the lateral angle is greater than or equal to about 45° and less than about 90°.

6. The recording head of claim 1 , wherein:
one or both of the convex shape and the concave shape comprises one or both of a vertical angle and a lateral angle; and
the vertical angle is different than the lateral angle.

7. The recording head of claim 1 , wherein:
one or both of the convex shape and the concave shape comprises one or both of a vertical angle and a lateral angle; and
the vertical angle is substantially the same as the lateral angle.

8. A recording head, comprising:
a channel waveguide that delivers light to a media-facing surface;
a near-field transducer (NFT) at an end of the channel waveguide and proximate to the media-facing surface; and
a laser comprising an active region formed of a non-self supporting, crystalline layer transfer printed to a substrate, the active region having a longitudinal axis corresponding to a propagation direction of the channel waveguide, the active region comprising a back facet and a front facet proximate the NFT, the front facet having a surface shape configured to suppress back reflection of the light, the surface shape of the front facet comprising a curved shape and one or both of a convex shape and a concave shape.

9. The recording head of claim 8 , wherein one or both of the convex shape and the concave shape is off centered with respect to the longitudinal axis.

10. The recording head of claim 8 , wherein the surface shape is configured to allow forward light transmission and reduce feedback.

11. The recording head of claim 8 , wherein the surface shape of the front facet is configured to suppress an amount of feedback in the range of about 20% to about 30%.

12. The recording head of claim 8 , wherein:
the curved shape comprises one or both of a vertical angle and a lateral angle; and
the one or both of the vertical angle and the lateral angle is greater than or equal to about 45° and less than about 90°.

13. A recording head, comprising:
a channel waveguide that delivers light to a media-facing surface;
a near-field transducer (NFT) at an end of the channel waveguide and proximate to the media-facing surface; and
a laser comprising an active region formed of a non-self supporting, crystalline layer transfer printed to a substrate, the active region having a longitudinal axis corresponding to a propagation direction of the channel waveguide, the active region comprising a back facet and a front facet proximate the NFT, the front facet having a surface shape configured to suppress back reflection of the light, the surface shape of the front facet comprising a curved shape.

14. The recording head of claim 13 , wherein the curved shape is off centered with respect to the longitudinal axis.

15. The recording head of claim 13 , wherein the surface shape is configured to allow forward light transmission and reduce feedback.

16. The recording head of claim 13 , wherein the surface shape of the front facet is configured to suppress an amount of feedback in the range of about 20% to about 30%.

17. The recording head of claim 13 , wherein:
the curved shape comprises one or both of a vertical angle and a lateral angle; and
the one or both of the vertical angle and the lateral angle is greater than or equal to about 45° and less than about 90°.

18. The recording head of claim 13 , wherein:
the curved shape comprises one or both of a vertical angle and a lateral angle; and
the one or both of the vertical angle and the lateral angle is about 85°.

19. The recording head of claim 13 , wherein:
the curved shape comprises one or both of a vertical angle and a lateral angle; and
the vertical angle is different than the lateral angle.

20. The recording head of claim 13 , wherein:
the curved shape comprises one or both of a vertical angle and a lateral angle; and
the vertical angle is substantially the same as the lateral angle.

Assignees

• Seagate Technology Llc

Inventors

• Goggin Aidan Dominic
• Moloney John
• Mehfuz Reyad
• Zhong Chuan
• Harvey Christopher Neil

Classifications

• G11B11/105

  using a beam of light or a magnetic field for recording {by change of magnetisation} and a beam of light for reproducing, {i.e. magneto-optical,} e.g. light-induced thermomagnetic recording, {spin magnetisation recording,} Kerr {or Faraday} effect reproducing · 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

• G11B5/6088 Primary

  Optical waveguide in or on flying head · CPC title

• G11B5/4866

  the arm comprising an optical waveguide, e.g. for thermally-assisted recording · CPC title

• G11B13/08 Primary

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