OPTICAL SENSING DEVICE

• US 20080291446A1
• Filed: 12/01/2006
• Published: 11/27/2008
• Est. Priority Date: 12/01/2006
• Status: Active Grant

• Current Assignee: 3M Innovative Properties Company (3M Company)
• Original Assignee: 3M Innovative Properties Company (3M Company)
• Inventors: Smith, Terry L., Koch, Barry J., Yi, Yasha
• Granted Patent: US 7,903,240 B2
• Time in Patent Office: Days
• US Class Current: 356/338
• CPC Class Codes: G01N 21/7746 the waveguide coupled to a cavity resonator
• CPC Class Codes: G02B 6/12007 forming wavelength selective elements, e.g. multiplexer, demultiplexer
• CPC Class Codes: G02B 6/29338 Loop resonators

Abstract

An optical sensing system and method are disclosed. The optical sensing system includes one or more bus waveguides. A first bus waveguide includes an input port that is in optical communication with a light source. The system further includes a microresonator optically coupled to the bus waveguides and an optical scattering center configured for alteration of a strength of optical coupling between the optical scattering center and the microresonator. In addition, the system includes a detector in optical communication one of the bus waveguides or the microresonator.

Claims

1. An optical sensing system comprising:

a first bus waveguide, the first bus waveguide comprising an input port that is in optical communication with a light source;

a second bus waveguide comprising a drop two port;

a microresonator optically coupled to the first and second bus waveguides;

an optical scattering center configured for alteration of a strength of optical coupling between the optical scattering center and the microresonator; and

a detector in optical communication with the drop two port, wherein the optical sensing system is configured so that, in the absence of a scattering center optically coupled to the microresonator, light launched at the input port couples to a first guided optical mode of the microresonator and the first guided optical mode primarily does not couple to the drop two port.

2. The system of claim 1 wherein the microresonator is selected from a disk microresonator, a ring microresonator, a toroidal microresonator, and a racetrack microresonator.

3. The system of claim 1 wherein the scattering center comprises a particle.

4. The system of claim 3 wherein the particle is a nanoparticle.

5. The system of claim 4 wherein the nanoparticle is a metallic nanoparticle, a semiconductor nanoparticle, or a dielectric nanoparticle.

6. The system of claim 1 wherein the scattering center is a region of variable refractive index embedded in the core of the resonator.

7. The system of claim 1 wherein the second bus waveguide further comprises a drop port, wherein the optical sensing system is configured so that, in the absence of the scattering center optically coupled to the microresonator, the first guided optical mode of the microresonator couples to the drop port.

8. The system of claim 1 wherein the drop two port is primarily capable of optically coupling to a second guided optical mode of the microresonator and the detector is configured to detect the second guided optical mode.

9. The system of claim 8 wherein the optical sensing system is configured so that an alteration of the strength of optical coupling between the optical scattering center and the microresonator induces a change in optical scattering from the first resonant guided optical mode to the second guided optical mode.

10. The system of claim 9 wherein the optical sensing system is configured to detect the change in optical scattering at the detector at the drop two port.

11. The system of claim 1 wherein the microresonator and the first bus waveguide are integrated on a substrate.

12. The system of claim 11 wherein the light source is integrated on the substrate.

13. The system of claim 11 wherein the detector is integrated on the substrate.

14. The system of claim 1 wherein the microresonator is optically coupled to the first and second bus waveguides by a vertical coupling.

15. The system of claim 1, wherein the microresonator is optically coupled to the first and second bus waveguides by a lateral coupling.

16. The system of claim 1, wherein the microresonator is optically coupled to the first and second bus waveguides by evanescent coupling.

17. The system of claim 1, wherein the microresonator is optically coupled to the first and second bus waveguides by core coupling.

18. The system of claim 1, wherein the microresonator is optically coupled to the first and second bus waveguides via a multimode interference coupler.

19. An optical sensing system comprising:

one or more bus waveguides, comprising a first bus waveguide, the first bus waveguide comprising an input port that is in optical communication with a light source;

a microresonator optically coupled to the one or more bus waveguides; and

a detector in optical communication with the input port.

20. The system of claim 19 wherein the microresonator is selected from a disk microresonator, a ring microresonator, a toroidal microresonator, and a racetrack microresonator.

21. The system of claim 19 wherein the optical sensing system further comprises an optical scattering center configured for alteration of a strength of optical coupling between the optical scattering center and the microresonator.

22. The system of claim 19 wherein the microresonator and the first bus waveguide are integrated on a substrate.

23. The system of claim 22, wherein the light source is integrated on the substrate.

24. The system of claim 22 wherein the detector is integrated on the substrate.

25. The system of claim 19, further comprising an optical circulator in optical communication with the input port, wherein the optical circulator enables optical coupling of the second mode to the detector.

26. The system of claim 19, further comprising an optical splitter in optical communication with the input port, wherein the optical splitter enables optical coupling of the second mode to the detector.

27. An optical sensing system comprising:

a first bus waveguide, the first bus waveguide comprising an input port that is in optical communication with a light source;

a second bus waveguide comprising a drop port and a drop two port;

a microresonator optically coupled to the first and second bus waveguides; and

a detector in optical communication with the second bus waveguide, wherein;

(a) light launched at the input port is capable of coupling to;

i. a first guided optical mode of the microresonator; and

ii. a second guided optical mode of the microresonator that occurs primarily when a scattering center is in optical communication with the microresonator;

(b) the drop port is primarily capable of optically coupling to the first guided optical mode of the microresonator and is primarily not capable of coupling to the second guided optical mode;

(c) the drop two port is primarily capable of optically coupling to the second guided optical mode of the microresonator and is primarily not capable of coupling to the first guided optical mode,

(d) the detector is in optical communication with the drop two port.

28. The system of claim 27 wherein the microresonator is selected from a disk microresonator, a ring microresonator, a toroidal microresonator, and a racetrack microresonator.

29. The system of claim 27 wherein optical sensing system comprises a scattering center configured for alteration of a strength of optical coupling between the optical scattering center and the microresonator.

30. The system of claims 29 wherein the scattering center comprises a particle.

31. The system of claim 30 wherein the particle is a nanoparticle.

32. The system of claim 31 wherein the nanoparticle is a metallic nanoparticle, a semiconductor particle, or a dielectric nanoparticle.

33. The system of claim 29 wherein the scattering center is a region of variable refractive index embedded in a core of the resonator.

34. The system of claim 27 wherein the microresonator, the first bus waveguide, and the second bus waveguide are integrated on a substrate.

35. The system of claim 34 wherein the light source is integrated on the substrate.

36. The system of claim 34 wherein the detector is integrated on the substrate.

37. The system of claim 27 wherein the microresonator is optically coupled to the first and second bus waveguides by a vertical coupling.

38. The system of claim 27, wherein the microresonator is optically coupled to the first and second bus waveguides by a lateral coupling.

39. An optical sensing system comprising:

one or more bus waveguides, comprising a first bus waveguide, the first bus waveguide comprising an input port that is in optical communication with a light source;

a disk microresonator optically coupled to the one or more bus waveguides, the disk microresonator defining a center location; and

a detector in optical communication with the disk microresonator and located at the center location of the disk microresonator.

40. The system of claim 39 wherein the microresonator, the first bus waveguide, the light source, and the detector are integrated on a substrate.

41. The system of claim 40, wherein the light source is hybridly integrated on the substrate.

42. The system of claim 40, wherein the microresonator, the first bus waveguide, and the detector are monolithically integrated on the substrate.

43. The system of claim 39, wherein the optical sensing system further comprises an optical scattering center configured for alteration of a strength of optical coupling between the optical scattering center and the microresonator.

44. The system of claim 43 wherein the scattering center comprises a particle.

45. The system of claim 44 wherein the particle is a nanoparticle.

46. The system of claim 45 wherein the nanoparticle is a metallic nanoparticle, a semiconductor nanoparticle, or a dielectric nanoparticle.

47. The system of claim 43 wherein the scattering center is a region of variable refractive index embedded in a core of the resonator.