Magnetic recording apparatus having thermal sensor and a solid-immersion mirror

Patent metadata

Field	Value
Publication number	US-9911441-B1
Application number	US-201615381015-A
Country	US
Kind code	B1
Filing date	Dec 15, 2016
Priority date	Dec 15, 2016
Publication date	Mar 6, 2018
Grant date	Mar 6, 2018

Abstract

A solid-immersion mirror has two reflective portions surrounding a focal region. A thermal sensor that senses temperature as a function of resistance is proximate at least one of the two reflective portions of the solid-immersion mirror. A near-field transducer is located proximate the focal region of the solid-immersion mirror. The near-field transducer directs optical energy to a magnetic recording medium.

First claim

What is claimed is:

1. An apparatus, comprising:
an optical coupling path that receives light energy from an energy source;
a solid-immersion mirror configured to reflect the light energy from the optical coupling path to a focal region, the solid-immersion mirror comprising two reflective portions surrounding the focal region;
a thermal sensor that senses temperature as a function of resistance, the thermal sensor layered directly over at least one of the two reflective portions of the solid-immersion mirror; and
a near-field transducer located proximate the focal region of the solid-immersion mirror, the near-field transducer directing the light energy to a magnetic recording medium via a media-facing surface of the apparatus.

2. The apparatus of claim 1 , further comprising a second thermal sensor layered directly over the other reflective portion of the solid-immersion mirror.

3. The apparatus of claim 2 , wherein the thermal sensor and the second thermal sensor are wired together in parallel or in series.

4. The apparatus of claim 1 , wherein the solid-immersion mirror comprises a film of reflective material, the film having a first thickness proximate the near-field transducer and a second thickness away from the near-field transducer, the second thickness being greater than the first thickness.

5. The apparatus of claim 1 , wherein a change in the temperature is used to detect at least one of spacing changes and contact between the apparatus and the magnetic recording medium.

6. The apparatus of claim 1 , wherein a change in the temperature is used to adjust operation of the energy source during use.

7. The apparatus of claim 1 , wherein a change the temperature is used to align the energy source to the apparatus during a factory process.

8. The apparatus of claim 1 , wherein the optical coupling path comprises a waveguide that overlaps and delivers light to the near-field transducer, solid-immersion mirror being located at an end of the waveguide proximate the media-facing surface.

9. The apparatus of claim 1 , wherein the near-field transducer extends a first distance away from the media-surface and the solid-immersion mirror extends a second distance away from the media-surface, the second distance being less than the first distance.

10. The apparatus of claim 1 , wherein the optical coupling path comprises a waveguide core and waveguide cladding, wherein the solid-immersion mirror is etched through at least the waveguide core.

11. A method comprising:
directing energy from a light source to an optical coupling path of a recording head;
reflecting the energy from the optical coupling path to a near-field transducer located at a focal region of a solid-immersion mirror, the near-field transducer directing the energy to a magnetic recording medium via a media-facing surface of the recording head;
sending an electrical signal through a thermal sensor layered directly over the solid-immersion mirror; and
detecting temperature as a function of resistance of the thermal sensor based on a response of the signal.

12. The method of claim 11 , further comprising using the temperature to detect at least one of spacing changes and contact between the recording head and the magnetic recording medium.

13. The method of claim 11 , further comprising using a change in the temperature to adjust operation of the light source during use.

14. The method of claim 11 , further comprising using a change in the temperature to align the light source to the apparatus during a factory process.

15. A system comprising:
a recording head comprising:
a laser;
a waveguide system optically coupled to the laser;
a solid-immersion mirror at an end of the waveguide, the solid-immersion mirror comprising two reflective portions surrounding a focal region;
a thermal sensor that senses temperature as a function of resistance, the thermal sensor layered directly over at least one of the two reflective portions of the solid-immersion mirror; and
a heater configured to affect a clearance between the recording head and the recording medium; and

a circuit coupled to the recording head; the circuit configured to:
pass a current through the thermal sensor;
based on the current, determine a resistance of the thermal sensor; and
based on the resistance, actively control a power level of at least one of the laser and the heater.

16. The system of claim 15 , further comprising a second thermal sensor layered directly over the other reflective portion of the solid-immersion mirror, the circuit further configured to pass a second current through the second thermal sensor and determine a second resistance in response thereto, the controlling of the power level using both the resistance and the second resistance.

17. The system of claim 16 , wherein the thermal sensor and the second thermal sensor are wired together in parallel or in series.

18. The system of claim 15 , wherein the solid-immersion mirror comprises a film of reflective material, the film having a first thickness proximate the near-field transducer and a second thickness away from the near-field transducer, the second thickness being greater than the first thickness.

19. The system of claim 15 , wherein at least part of the thermal sensor away from a media-facing surface of the recording head is coated with reflective material.

Assignees

• Seagate Technology Llc

Inventors

• Jandric Zoran
• Blaber Martin
• Peng Chubing
• Duda John Charles

Classifications

• 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

• 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

• G11B5/4866 Primary

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