Method of using a unidirectional crow gyroscope

• US 8,705,044 B2
• Filed: 09/20/2011
• Issued: 04/22/2014
• Est. Priority Date: 04/01/2008
• Status: Expired due to Fees

• Current Assignee: Board of Trustees of the Leland Stanford Junior University (Stanford Management Co.)
• Original Assignee: Board of Trustees of the Leland Stanford Junior University (Stanford Management Co.)
• Inventors: Terrel, Matthew A., Digonnet, Michel J. F., Fan, Shanhui
• Primary Examiner(s): Chowdhury, Tarifur
• Assistant Examiner(s): Cook, Jonathon
• Application Number:
  US13/237,591
• Publication Number:
  US 20120069346A1
• Time in Patent Office: 945 Days
• Field of Search: 356459-361
• US Class Current: 356/461
• CPC Class Codes: G01C 19/721 Details
• CPC Class Codes: G01C 19/727 using a passive ring resonator

Abstract

A method for detecting rotation includes providing a plurality of resonant waveguides generally adjacent to one another and optically coupled to one another. Each resonant waveguide of the plurality of resonant waveguides is configured to allow light to propagate along the resonant waveguide in a planar path. The method further includes propagating light along each path in a clockwise direction or along each path in a counterclockwise direction.

Claims

1. A method of detecting rotation, the method comprising:

providing a plurality of resonant waveguides adjacent to one another and optically coupled together, wherein each resonant waveguide of the plurality of resonant waveguides is configured to allow light to propagate along the resonant waveguide in a planar path that surrounds an area substantially bounded by the resonant waveguide; and

propagating at least a portion of a light signal sequentially along each path in a clockwise direction relative to the area surrounded by the path or along each path in a counterclockwise direction relative to the area surrounded by the path.

2. The method of claim 1, wherein the plurality of resonant waveguides comprises a first resonant waveguide configured to allow light to propagate along the first resonant waveguide in a first path surrounding a first area and a second resonant waveguide adjacent to the first resonant waveguide and configured to allow light to propagate along the second resonant waveguide in a second path surrounding a second area, and said propagating at least the portion of the light signal comprises propagating the light either successively through the first resonant waveguide along the first path in a clockwise direction relative to the first area and through the second resonant waveguide along the second path in a clockwise direction relative to the second area, or successively through the first resonant waveguide along the first path in a counterclockwise direction relative to the first area and through the second resonant waveguide along the second path in a counterclockwise direction relative to the second area.

3. The method of claim 1, wherein at least one of the resonant waveguides comprises at least one ring waveguide.

4. The method of claim 1, wherein at least one of the resonant waveguides comprises at least one microresonator.

5. The method of claim 1, wherein the resonant waveguides are positioned such that the planar paths of the plurality of resonant waveguides are in a common plane.

6. The method of claim 5, wherein the resonant waveguides are positioned along a straight line.

7. The method of claim 5, wherein the resonant waveguides are positioned along a curved line.

8. The method of claim 1, wherein each planar path has a normal direction perpendicular to the path, and the resonant waveguides are positioned such that the normal directions of the paths are coincident with one another.

9. The method of claim 1, wherein at least one of the resonant waveguides includes a twisted portion optically coupled to an adjacent resonant waveguide.

10. The method of claim 1, wherein at least one of the resonant waveguides is optically coupled to an adjacent resonant waveguide by a ring waveguide having an area smaller than the area of the at least one of the resonant waveguides.

11. The method of claim 1, wherein a coupling ratio between adjacent resonant waveguides of the plurality of resonant waveguides is less than one.

12. The method of claim 1, wherein adjacent resonant waveguides of the plurality of resonant waveguides are optically coupled by an optical coupler disposed between the adjacent resonant waveguides.

13. The method of claim 12, wherein the optical coupler comprises a ring resonator, a twisted portion of a resonant waveguide of the adjacent resonant waveguides, or portions of the adjacent resonant waveguides spaced sufficiently close to one another to allow light to propagate between the adjacent resonant waveguides.

14. A method of detecting rotation, the method comprising:

providing an optical waveguide gyroscope comprising a plurality of resonant waveguides adjacent to one another and optically coupled to one another;

propagating at least a portion of a first optical signal through the plurality of resonant waveguides such that the at least a portion of the first optical signal propagates sequentially through each resonant waveguide of the plurality of resonant waveguides in a clockwise direction relative to an area surrounded and substantially bounded by the resonant waveguide;

propagating at least a portion of a second optical signal through the plurality of resonant waveguides such that the at least a portion of the second optical signal propagates sequentially through each resonant waveguide of the plurality of resonant waveguides in a counterclockwise direction relative to the area surrounded and substantially bounded by the resonant waveguide.

15. The method of claim 14, wherein a first resonant waveguide and a second resonant waveguide of the plurality of resonant waveguides are adjacent to one another and are optically coupled to one another by a coupling portion of the first resonant waveguide, wherein the coupling portion comprising two sections of the first resonant waveguide that cross over one another.

16. The method of claim 15, wherein the coupling portion comprises a 180 degree twist of the first resonant waveguide, the first resonant waveguide is planar and surrounds a first area, the coupling portion between the twist and the second resonant waveguide is planar and surrounds a second area less than 10% of the first area.

17. The method of claim 14, wherein a first resonant waveguide and a second resonant waveguide of the plurality of resonant waveguides are adjacent to one another, the first resonant waveguide and the second resonant waveguide are optically coupled to one another by a ring resonator.

18. The method of claim 17, wherein the first resonant waveguide is planar and surrounds a first area, the second resonant waveguide is planar and surrounds a second area, and the ring resonator is generally planar and generally surrounds a third area, the third area smaller than the first area and smaller than the second area.

19. The method of claim 18, wherein the third area is less than 10% of the first area and less than 10% of the second area.

20. The method of claim 14, further comprising combining the at least a portion of the first optical signal after propagating through the plurality of resonant waveguides and the at least a portion of the second optical signal after propagating through the plurality of resonant waveguides.

21. The method of claim 14, wherein each resonant waveguide of the plurality of resonant waveguides is planar, and the resonant waveguides are parallel to one another.

22. The method of claim 21, wherein the resonant waveguides are planar with one another.

23. The method of claim 22, wherein the resonant waveguides are positioned along a straight line.

24. The method of claim 22, wherein the resonant waveguides are positioned along a curved line.

25. The method of claim 21, wherein each resonant waveguide defines a normal direction perpendicular to the resonant waveguide, and the resonant waveguides are positioned such that the normal directions are coincident with one another.

26. The method of claim 21, wherein the resonant waveguides are stacked above one another.