Diffraction grating

• US 7,266,268 B2
• Filed: 01/10/2005
• Issued: 09/04/2007
• Est. Priority Date: 09/05/2003
• Status: Active Grant

• Current Assignee: Seagate Technology LLC (Seagate Technology Holdings Plc)
• Original Assignee: Seagate Technology LLC (Seagate Technology Holdings Plc)
• Inventors: Challener, William A., Rausch, Tim, Gage, Edward C., Mountfield, Keith, Mihalcea, Christophe
• Primary Examiner(s): HEALY, BRIAN
• Application Number:
  US11/032,277
• Publication Number:
  US 20050135008A1
• Time in Patent Office: 967 Days
• Field of Search: 385/129, 385/130, 385/131, 385/132, 385/14, 385/37
• US Class Current: 385/37
• CPC Class Codes: G11B 2005/0002 Special dispositions or recording techniques
• CPC Class Codes: G11B 2005/0005 Arrangements, methods or circuits
• CPC Class Codes: G11B 2005/0013 of transducers, e.g. linearisation, equalisation
• CPC Class Codes: G11B 2005/0021 Thermally assisted recording using an auxiliary energy source for heating the recording layer locally to assist the magnetization reversal
• CPC Class Codes: G11B 5/02 Recording, reproducing, or erasing methods; Read, write or erase circuits therefor
• CPC Class Codes: G11B 5/10 Structure or manufacture of housings or shields for heads
• CPC Class Codes: G11B 5/1278 specially adapted for magnetisations perpendicular to the surface of the record carrier
• CPC Class Codes: G11B 5/314 where the layers are extra layers normally not provided in the transducing structure, e.g. optical layers G11B5/3196 takes precedence
• CPC Class Codes: G11B 5/6088 Optical waveguide in or on flying head

Abstract

Diffraction gratings for coupling an electromagnetic wave into a planar waveguide are disclosed. The diffraction grating may include a first diffraction grating and a second diffraction grating slanted relative to one another. Alternatively, the diffraction grating may include a first diffraction grating and a second diffraction grating spaced apart to form a gap therebetween.

Claims

1. An apparatus, comprising:

a solid immersion mirror planar waveguide; and

first and second diffraction gratings for directing first and second electromagnetic waves into the solid immersion mirror planar waveguide;

wherein the first diffraction grating and the second diffraction grating are spaced apart to form a gap therebetween.

2. The apparatus of claim 1, wherein the solid immersion mirror planar waveguide includes a truncated end and the width of the gap is substantially equal to the width of the truncated end.

3. The apparatus of claim 1, wherein the first diffraction grating and the second diffraction grating are slanted relative to each other.

4. The apparatus of claim 1, wherein the planar waveguide includes a first edge and a second edge, the first and second edges being shaped for directing the electromagnetic waves to a predetermined point.

5. The apparatus of claim 4, wherein the first and second edges form a substantially parabolic shape.

6. The apparatus of claim 4, wherein the first and second edges are structured and arranged as a function of an angle of at least one of the first diffraction grating and the second diffraction grating.

7. The apparatus of claim 1, wherein the first diffraction grating is positioned at a grating angle in the range of about zero degrees to about twenty degrees.

8. The apparatus of claim 7, wherein the second diffraction grating is positioned at a grating angle in the range of about zero degrees to about twenty degrees.

9. The apparatus of claim 1, wherein the first diffraction grating and the second diffraction grating direct the first electromagnetic wave and the second electromagnetic wave around a dead zone area of the planar waveguide.

10. An apparatus comprising:

a solid immersion mirror planar waveguide; and

first and second diffraction gratings for directing first and second electromagnetic waves into the solid immersion mirror planar waveguide;

wherein the first diffraction grating and the second diffraction grating are slanted relative to each other.

11. The apparatus of claim 10, wherein the solid immersion mirror planar waveguide includes a first and a second edge, the first and second edges being shaped for directing the electromagnetic waves to a predetermined point.

12. The apparatus of claim 11, wherein the first and second edges form a substantially parabolic shape.

13. The apparatus of claim 11, wherein the first and second edges form a shape that is a function of an angle of at least one of the first and second diffraction gratings.

14. The apparatus of claim 10, wherein the first diffraction grating is positioned at a grating angle in the range of about zero degrees to about twenty degrees.

15. The apparatus of claim 14, wherein the second diffraction grating is positioned at a grating angle in the range of about zero degrees to about twenty degrees.

16. The apparatus of claim 10, wherein the first diffraction grating and the second diffraction grating direct the electromagnetic waves around a dead zone area of the planar waveguide.