METHOD OF USING A UNIDIRECTIONAL CROW GYROSCOPE

• US 20120069346A1
• Filed: 09/20/2011
• Published: 03/22/2012
• Est. Priority Date: 04/01/2008
• Status: Active Grant

• 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
• Granted Patent: US 8,705,044 B2
• Time in Patent Office: Days
• US Class Current: 356/471
• 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; and

propagating light along each path in a clockwise direction or along each path in a counterclockwise direction.

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 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, and said propagating light comprises propagating the light either successively through the first resonant waveguide along the first path in a clockwise direction and through the second resonant waveguide along the second path in a clockwise direction, or successively through the first resonant waveguide along the first path in a counterclockwise direction and through the second resonant waveguide along the second path in a counterclockwise direction.

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 an 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. 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 through each resonant waveguide of the plurality of resonant waveguides in a clockwise direction;

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 through each resonant waveguide of the plurality of resonant waveguides in a counterclockwise direction.

13. The method of claim 12, 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.

14. The method of claim 13, 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.

15. The method of claim 12, 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.

16. The method of claim 15, 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.

17. The method of claim 16, wherein the third area is less than 10% of the first area and less than 10% of the second area.

18. The method of claim 12, 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.

19. The method of claim 12, wherein each resonant waveguide of the plurality of resonant waveguides is planar, and the resonant waveguides are parallel to one another.

20. The method of claim 19, wherein the resonant waveguides are planar with one another.

21. The method of claim 20, wherein the resonant waveguides are positioned along a straight line.

22. The method of claim 20, wherein the resonant waveguides are positioned along a curved line.

23. The method of claim 19, 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.

24. The method of claim 19, wherein the resonant waveguides are stacked above one another.

25. 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, wherein the paths of each of the resonant waveguides of the plurality of waveguides are parallel to one another, at least one of the resonant waveguides including a twisted portion optically coupled to an adjacent resonant waveguide; and

propagating light along each path in a clockwise direction or along each path in a counterclockwise direction.