Optical cross connect switching array system with optical feedback

• US 6,483,962 B1
• Filed: 05/24/2001
• Issued: 11/19/2002
• Est. Priority Date: 05/24/2000
• Status: Expired due to Fees

• Current Assignee: Vlad J. Novotny
• Original Assignee: Vlad J. Novotny
• Inventors: Novotny, Vlad J.
• Primary Examiner(s): Lee, John D.
• Assistant Examiner(s): KNAUSS, SCOTT A
• Application Number:
  US09/865,981
• Time in Patent Office: 544 Days
• Field of Search: 385/16-23, 359/223-226, 359/290, 359/291
• US Class Current: 385/18
• CPC Class Codes: G02B 6/32 having lens focusing means positioned between opposed fibre ends with lens being an integral part of the single fibre end G02B6/262
• CPC Class Codes: G02B 6/3518 the reflective optical element being an intrinsic part of a MEMS device, i.e. fabricated together with the MEMS device MEMS devices in general B81B; manufacture of MEM devices in general B81C; micromechanical devices controlling the direction of light G02B26/0833
• CPC Class Codes: G02B 6/3556 NxM switch, i.e. regular arrays of switches elements of matrix type constellation
• CPC Class Codes: G02B 6/357 Electrostatic force electrostatic forces controlling reflecting elements in general G02B26/0841
• CPC Class Codes: G02B 6/3584 constructional details of an associated actuator having a MEMS construction, i.e. constructed using semiconductor technology such as etching MEMS per se B81B, B81C
• CPC Class Codes: G02B 6/359 of the position of the moving element itself during switching, i.e. without monitoring the switched beams

Abstract

An optical cross connect switch directs an optical data signal from an incoming optical fiber in a first fiber array to a first controllable mirror in a first controllable mirror array, a second controllable mirror in a second controllable mirror array into an outgoing optical fiber in a second fiber array. A position sensing detector array determines the position of the light with respect to fiber cores to provide feedback control to the controllable mirror arrays.

Claims

1. An optical cross connect switching system for directing optical signals from incoming fibers in a first optical fiber array to selected destination outgoing fibers in a second optical fiber array, the system comprising:

a first mirror array for controllably reflecting the optical signals received from the incoming fibers to the selected destination outgoing fibers, and comprising a plurality of controllably deflectable mirrors and an input;

a first position sensitive detector array for detecting the position of optical signals incident thereon, the position of optical signals incident thereon corresponding to the position of the optical signals incident on the selected destination outgoing fibers in the second optical fiber array, and comprising an output; and

a system controller coupled to the output of the first position sensitive detector array and to the input of the first mirror array, for controlling the deflections of the mirrors of the first mirror array in response to the destination outgoing fibers selected for the optical data signals and in response to the detected positions of the optical signals.

2. The system of claim 1, further comprising light intensity monitors coupled to the outgoing fibers and the system controller for monitoring the intensity of the optical signals received by the selected destination outgoing fibers and outputting the intensity of the optical signals received by the selected destination outgoing fibers to the system controller.

3. The system of claim 1 further comprising:

a second mirror array for controllably reflecting the optical signals from the first mirror array into the outgoing fibers, and comprising a plurality of controllably deflectable mirrors and an input; and

wherein;

each incoming fiber is aligned with one of the mirrors in the first mirror array;

each outgoing fiber is aligned with one of the mirrors in the second mirror array; and

the system controller is further coupled to the input of the second mirror array to control the deflections of the first and second mirror arrays, to reflect each optical signal from the incoming optical fiber to the mirror in the first mirror array that is aligned with the incoming optical fiber to the mirror in the second mirror array that is aligned with the selected destination outgoing fiber to the selected destination outgoing fiber.

4. The system of claim 3 further comprising a second position detector array for detecting the position of optical signals incident thereon, the position of optical signals incident thereon corresponding to the position of the optical signals incident on selected incoming fibers in the first optical fiber array, and comprising an output coupled to the system controller, wherein the system controller further controls the deflections of the mirrors in the first and second mirror arrays in response to the positions of the optical signals detected by the second position detector array.

5. The system of claim 4, wherein the second position detector array is selected from a group consisting of a bi-lateral position sensitive detector array, a quadrant position sensitive detector array, a charged coupled device (CCD) array, a complementary metal oxide semiconductor (CMOS) array, and an infrared imaging array.

6. The system of claim 4, wherein the optical signals have a data signal wavelength and the first and second position detector arrays are sensitive at the data signal wavelength.

7. The system of claim 4, further comprising a registration light source coupled to an incoming fiber in the first optical fiber array for adding a registration light signal to the optical signals, wherein the registration light signal is at a different wavelength than data signals within the optical signals but is coincident with the data signals when leaving the first optical fiber array, and wherein the first and second position detector arrays are sensitive at the registration light signal wavelength.

8. The system of claim 3 further comprising a beamsplitter for splitting off a portion of the optical signal reflected from the second mirror array and directing said portion towards the first position sensitive detector array.

9. The system of claim 3 further comprising:

a registration light source coupled to an incoming fiber in the first optical fiber array for adding a registration light signal to the optical signals, wherein the registration light signal is at a different wavelength than data signals within the optical signals but is coincident with the data signals when leaving the first optical fiber array; and

a coarse wavelength division demultiplexer for reflecting the registration light towards the first position sensitive detector array and transmitting data optical signals to a face of the second optical fiber array.

10. The system of claim 3 further comprising:

a registration light source coupled to an incoming fiber in the first optical fiber array for adding a registration light signal to the optical signals, wherein the registration light signal is at a different wavelength than data signals within the optical signals but is coincident with the data signals when leaving the first optical fiber array; and

a coarse wavelength division demultiplexer for reflecting registration light back-reflected from a face of the second optical fiber array and directing said portion towards the first position sensitive detector array and transmitting data optical signal to a face of the second optical fiber array.

11. The system of claim 3 further comprising:

a first lens array having a lens associated with each of the incoming fibers;

wherein each lens is positioned to collimate the optical signals from the incoming fiber in the first optical fiber array onto the first mirror array;

wherein each lens-incoming fiber combination comprises an incoming fiber-lens assembly; and

wherein each incoming fiber-lens assembly is aligned with one of the mirrors in the first mirror array.

12. The system of claim 3 further comprising:

a second lens array having a lens associated with each of the outgoing fibers;

wherein each lens is positioned to focus the optical signals onto the outgoing fiber in the second optical fiber array;

wherein each lens-outgoing fiber combination comprises an outgoing fiber-lens assembly; and

wherein each outgoing fiber-lens assembly is aligned with one of the mirrors in the second mirror array.

13. The system of claim 3 wherein the first position detector array is placed between the second mirror array and the second optical fiber array.

14. The system of claim 3, wherein the second mirror array is a micro electro mechanical system (MEMS) mirror array.

15. The system of claim 3, wherein the second mirror array is one-dimensional array.

16. The system of claim 3, wherein the second mirror array is a two-dimensional array.

17. The system of claim 3 further comprising a second position sensitive detector array for detecting the position of optical signals incident thereon, the position of optical signals incident thereon corresponding to the position of the optical signals reflected from the first mirror array and corresponding to the position of the optical signals incident on the selected destination outgoing fibers in the second optical fiber array, and comprising an output coupled to the system controller, wherein the system controller further controls the deflections of the mirrors in the first and second mirror arrays in response to the positions of the optical signals detected by the second position detector array.

18. The system of claim 17 further comprising a beamsplitter for splitting off a portion of the optical signal reflected from the second mirror array and directing said portion towards the second position sensitive detector array.

19. The system of claim 17 further comprising:

a registration light source coupled to an incoming fiber in the first optical fiber array for adding a registration light signal to the optical signals, wherein the registration light signal is at a different wavelength than data signals within the optical signals but is coincident with the data signals when leaving the first optical fiber array; and

a coarse wavelength division demultiplexer for reflecting the registration light towards the second position sensitive detector array and transmitting data optical signals to a face of the second optical fiber array.

20. The system of claim 17 further comprising:

a registration light source coupled to an incoming fiber in the first optical fiber array for adding a registration light signal to the optical signals, wherein the registration light signal is at a different wavelength than data signals within the optical signals but is coincident with the data signals when leaving the first optical fiber array; and

a coarse wavelength division demultiplexer for reflecting registration light back-reflected from a face of the second optical fiber array and directing said portion towards the second position sensitive detector array and transmitting data optical signal to a face of the second optical fiber array.

21. The system of claim 17, further comprising:

a second lens array having a lens associated with each of the outgoing fibers;

wherein each lens is positioned to focus the optical signals onto the outgoing fiber in the second optical fiber array; and

wherein the second position detector array is positioned between the second lens array and the second optical fiber array.

22. The system of claim 21, further comprising:

a beamsplitter positioned between the second mirror array and the second lens array for splitting off a portion of the optical signal reflected from the second mirror array and directing said portion towards the second position detector array.

23. The system of claim 17 further comprising:

a beamsplitter positioned between the first and second mirror arrays; and

wherein the second position detector array is positioned adjacent to the beamsplitter.

24. The system of claim 17 further comprising third and fourth position detector arrays for detecting the position of optical signals incident thereon, the position of optical signals incident on the fourth position detector array corresponding to the position of the optical signals incident on selected outgoing fibers in the first optical fiber array, the position of optical signals on the third position detector array corresponding to the position of the optical signals incident on the mirrors in the second mirror array, and comprising an output coupled to the system controller, wherein the system controller further controls the deflections of the mirrors in the first and second mirror arrays in response to the positions of the optical signals detected by the second position detector array.

25. The system of claim 1 further comprising.

a first lens array having a lens associated with each of the incoming fibers;

wherein each lens is positioned to collimate the optical signals from the incoming fiber in the first optical fiber array onto the first mirror array; and

wherein each lens-incoming fiber combination comprises an incoming fiber-lens assembly.

26. The system of claim 25 wherein each incoming fiber-lens assembly is aligned with one of the mirrors in the first mirror array.

27. The system of claim 1 further comprising:

a second lens array having a lens associated with each of the outgoing fibers;

wherein each lens is positioned to focus the optical signals onto the outgoing fiber in the second optical fiber array; and

wherein each lens-outgoing fiber combination comprises an outgoing fiber-lens assembly.

28. The system of claim 27 wherein the first position detector array is positioned between the second lens array and the second optical fiber array.

29. The system of claim 27 wherein each outgoing fiber-lens assembly is aligned with one of the mirrors in the first mirror array.

30. The system of claim 1 wherein the optical signals on at least one of the incoming fibers and on at least one incoming wavelength in the first optical fiber array comprise an optical destination signal carrying information identifying the selected destination outgoing fibers for the optical signals on the incoming fibers, and further comprising a switch configuration controller with an input for receiving the optical destination signal and an output for outputting the identity of the selected destination outgoing fibers to the system controller.

31. The system of claim 1, further comprising a registration light source coupled to an incoming fiber in the first optical fiber array for adding a registration light signal to the optical signals, wherein the registration light signal is at a different wavelength than data signals within the optical signals but is coincident with the data signals when leaving the first optical fiber array.

32. The system of claim 31 wherein the first position sensitive detector array detects the position of the registration light signals.

33. The system of claim 31 further comprising:

a coarse wavelength division demultiplexer for reflecting the registration light towards the first position sensitive detector array and transmitting data optical signals to a face of the second optical fiber array.

34. The system of claim 31 further comprising:

a coarse wavelength division demultiplexer for reflecting registration light back-reflected from a face of the second optical fiber array and directing said portion towards the first position sensitive detector array and transmitting data optical signal to a face of the second optical fiber array.

35. The system of claim 31, wherein the registration light source has a wavelength and the first position detector array is sensitive at the wavelength of the registration light source.

36. The system of claim 1 further comprising a beamsplitter for splitting off a portion of the optical signal reflected from the first mirror array and directing said portion towards the first position sensitive detector array.

37. The system of claim 1 further comprising:

a beamsplitter for splitting off a portion of the optical signal back-reflected from a face of the second optical fiber array and directing said portion towards the first position sensitive detector array.

38. The system of claim 1 wherein the first position detector array is positioned between the first mirror array and the second optical fiber array.

39. The system of claim 1 further comprising a second position detector array for detecting the position of optical signals incident thereon, the position of optical signals incident thereon corresponding to the position of the optical signals incident on selected outgoing fibers in the first optical fiber array, and comprising an output coupled to the system controller, wherein the system controller further controls the deflections of the mirrors in the first mirror array in response to the positions of the optical signals detected by the second position detector array.

40. The system of claim 1, wherein the first mirror array is a micro electro mechanical system (MEMS) mirror array.

41. The system of claim 40, wherein the first mirror array is driven by bi-axial electrostatic actuators.

42. The system of claim 40, wherein the plurality of controllably deflectable mirrors of the first MEMS mirror array comprises bi-axial mirrors having two sets of hinges.

43. The system of claim 40, wherein the plurality of controllably deflectable mirrors of the first MEMS mirror array comprises a center torsional post.

44. The system of claim 40, wherein the plurality of controllably deflectable mirrors of the first MEMS mirror array has electrostatic drive.

45. The system of claim 40, wherein the plurality of controllably deflectable mirrors of the first MEMS mirror array comprises bi-axial mirrors having electromagnetic drive.

46. The system of claim 40, wherein the plurality of controllably deflectable mirrors of the first MEMS mirror array comprises bi-axial mirrors having piezoelectric drive.

47. The system of claim 1, wherein the first mirror array is one-dimensional array.

48. The system of claim 1, wherein the first mirror array is a two-dimensional array.

49. The system of claim 1, wherein the first position detector array is selected from a group consisting of a bilateral position sensitive detector array, a quadrant position sensitive detector array, a charged coupled device (CCD) array, a complementary metal oxide semiconductor (CMOS) array, and an infrared imaging array.

50. The system of claim 1, wherein the optical signals have a data signal wavelength and the first position detector array is sensitive at the data signal wavelength.

51. The system of claim 1 wherein the first position sensitive detector array comprises a plurality of detectors, and each detector is a bi-lateral position sensitive detection type detector.

52. A method for directing optical signals from incoming fibers in a first optical fiber array to selected destination outgoing fibers in a second optical fiber array, the method comprising:

determining the selected destination outgoing fibers;

reflecting, with a first mirror array comprising a plurality of controllably deflectable mirrors, the optical signals received from the incoming fibers to the selected destination outgoing fibers;

detecting the position of optical signals beams incident on a first position sensitive detector array, the position of optical signals incident thereon corresponding to the position of the optical signals incident on the selected destination outgoing fibers in the second optical fiber array; and

controlling deflections of the plurality of controllably deflectable mirrors in the first mirror array in response to the determined destination outgoing fibers and in response to the detected positions of the optical signals.

53. A method for directing optical signals from incoming fibers in a first optical fiber array to selected destination outgoing fibers in a second optical fiber array, the method comprising:

determining the selected destination outgoing fibers;

reflecting, with a first mirror array comprising a plurality of controllably deflectable mirrors, the optical signals received from the incoming fibers to mirrors in a second mirror array comprising a plurality of controllably deflectable mirrors;

reflecting, with the second mirror array, the optical signals received from the first mirror array to the selected destination outgoing fibers in the second optical fiber array;

detecting positions of optical signal beams reflected from the first mirror array incident on a first position sensitive detector array, the;

detecting positions of optical signal beams reflected from the second mirror array incident on a second position sensitive detector array, the position of optical signals incident thereon corresponding to a position of the optical signals incident on the selected destination outgoing fibers in the second optical fiber array; and

controlling deflections of the plurality of controllably deflectable mirrors in the first mirror array and the second mirror array in response to the determined destination outgoing fibers and in response to the detected positions of the optical signal beams.

54. A method for directing optical signals from a first set of incoming fibers in a first optical fiber array to a first set of selected outgoing fibers in a second optical fiber array, and for directing optical signals from a second set of incoming fibers in the second optical fiber array to a second set of selected outgoing fibers in the first optical fiber array, the method comprising:

determining the first set of selected outgoing fibers;

reflecting, with a first mirror array comprising a plurality of controllably deflectable mirrors, the optical signals received from the first set of incoming fibers to mirrors in a second mirror array comprising a plurality of controllably deflectable mirrors;

reflecting, with the second mirror array, the optical signals received from the first mirror array to the first set of selected outgoing fibers in the second optical fiber array;

detecting the position of optical signal beams incident on a first position sensitive detector array, the position of optical signals incident thereon corresponding to a position of the optical signals incident on the first set of selected outgoing fibers in the second optical fiber array;

controlling deflections of the plurality of controllably deflectable mirrors in the first mirror array and the second mirror array in response to the determined first set of selected outgoing fibers and in response to the detected positions of the optical signals on the first position sensitive detector array;

determining the second set of selected outgoing fibers;

reflecting, with the second mirror array, the optical signals received from the second set of incoming fibers to mirrors in the first mirror array;

reflecting, with the first mirror array, the optical signals received from the second mirror array to the second set of selected outgoing fibers in the first optical fiber array;

detecting the position of optical signal beams incident on a second position sensitive detector array, the position of optical signals incident thereon corresponding to a position of the optical signals incident on the second set of selected outgoing fibers in the first optical fiber array; and

controlling deflections of the plurality of controllably deflectable mirrors in the first mirror array and the second mirror array in response to the determined second set of selected outgoing fibers and in response to the detected positions of the optical signals incident on the second position sensitive detector array.

55. The method of claim 54 further comprising detecting the light intensities in the first set of selected outgoing fibers in the second optical fiber array, wherein the deflections of the plurality of controllably deflectable mirrors in the first mirror array and the second mirror array are further controlled in response to the light intensities in the first set of selected outgoing fibers in the second optical fiber array.

56. The method of claim 55 wherein the deflections of the plurality of controllably deflectable mirrors in the first mirror array and the second mirror array are controlled to maximize the light intensities in the first set of selected outgoing fibers in the second optical fiber array.

57. The method of claim 54 further comprising detecting the light intensities in the second set of selected outgoing fibers in the first optical fiber array, wherein the deflections of the plurality of controllably deflectable mirrors in the first mirror array and the second mirror array are further controlled in response to the light intensities in the second set of selected outgoing fibers in the first optical fiber array.

58. The method of claim 57 wherein the deflections of the plurality of controllably deflectable mirrors in the first mirror array and the second mirror array are controlled to maximize the light intensities in the second set of selected outgoing fibers in the first optical fiber array.

59. A method for directing optical signals from incoming fibers in a first optical fiber array to selected destination outgoing fibers in a second optical fiber array, the method comprising:

determining, for each incoming fiber, the selected destination outgoing fiber;

determining, for each incoming fiber, an optical path from the incoming fiber to at least one mirror array comprising a plurality of controllably deflectable mirrors, and to the selected destination outgoing fiber;

detecting the position of optical signal beams incident on a first position sensitive detector array, the position of optical signals incident thereon corresponding to a position of the optical signals incident on the selected destination outgoing fibers in the second optical fiber array; and

controlling deflections of the plurality of controllably deflectable mirrors in the at least one mirror array in response to the determined destination outgoing fibers, the determined optical path and in response to the detected positions of the optical signals to direct the optical signals from the incoming fibers to the selected destination outgoing fibers.

60. The method of claim 59, further comprising:

determining, for at least one incoming fiber, a new selected destination outgoing fiber;

determining, for the at least one incoming fiber, a new optical path from the at least one incoming fiber to the at least one mirror array comprising a plurality of controllably deflectable mirrors, and to the selected destination outgoing fiber;

detecting the position of an optical signal beam from the at least one incoming fiber incident on the first position sensitive detector array, the position of the optical signal from the at least one incoming fiber incident thereon corresponding to a position of the optical signal incident on the new selected destination outgoing fiber; and

controlling deflections of at least one of the plurality of controllably deflectable mirrors in the at least one mirror array in response to the determined new destination outgoing fiber, the determined new optical path and in response to the detected position of the optical signals to direct the optical signal from the at least one incoming fiber to the new selected destination outgoing fiber without redirecting the optical signals from the rest of the incoming fibers.

61. The method of claim 59, further comprising:

determining, for at least one incoming fiber, a new selected destination outgoing fiber;

determining, for the at least one incoming fiber, a new optical path from the at least one incoming fiber to the at least one mirror array comprising a plurality of controllably deflectable mirrors, and to the selected destination outgoing fiber;

detecting the position of an optical signal beam from the at least one incoming fiber incident on the first position sensitive detector array, the position of the optical signal from the at least one incoming fiber incident thereon corresponding to a position of the optical signal incident on the new selected destination outgoing fiber; and

controlling deflections of at least one of the plurality of controllably deflectable mirrors in the at least one mirror array in response to the determined new destination outgoing fiber, the determined new optical path and in response to the detected position of the optical signals to direct the optical signal from the at least one incoming fiber to close proximity to the new selected destination outgoing fiber without redirecting the optical signals from the rest of the incoming fibers.