Microelectromechanical optical cross-connect switches including mechanical actuators and methods of operating same

• US 6,445,842 B1
• Filed: 04/05/2000
• Issued: 09/03/2002
• Est. Priority Date: 04/05/2000
• Status: Expired due to Fees

• Current Assignee: Memscap Incorporated
• Original Assignee: Viavi Solutions, Inc. (Lumentum Holdings Inc.)
• Inventors: Hill, Edward A., Dhuler, Vijayakumar Rudrappa
• Primary Examiner(s): Sanghavi, Hemang
• Assistant Examiner(s): KNAUSS, SCOTT A
• Application Number:
  US09/542,170
• Time in Patent Office: 881 Days
• Field of Search: 385/16, 385/17, 385/18, 385/19, 385/20-22
• US Class Current: 385/17
• CPC Class Codes: G02B 26/0833 the reflecting element being a micromechanical device, e.g. a MEMS mirror, DMD G02B26/0825 takes precedence; micromechanical devices in general B81B
• CPC Class Codes: G02B 26/0841 the reflecting element being moved or deformed by electrostatic means
• CPC Class Codes: G02B 6/3514 the reflective optical element moving along a line so as to translate into and out of the beam path, i.e. across the beam path
• CPC Class Codes: G02B 6/3546 NxM switch, i.e. a regular array 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 6/358 Latching of the moving element, i.e. maintaining or holding the moving element in place once operation has been performed; includes a mechanically bistable system

Abstract

Microelectromechanical (MEM) Optical Cross-connect (OXC) switches having mechanical actuators are discussed. In particular, the MEM OXC switches can include a plurality of reflectors, wherein each of the plurality of the reflectors is movable to at least one of a respective first reflector position along a respective optical beam path from an associated input of the MEM OXC switch to an associated output thereof and a respective second reflector position outside the optical beam path. A mechanical actuator moves to at least one of a first mechanical actuator position and a second mechanical actuator position. A selector selects ones of the plurality of reflectors to be coupled to the mechanical actuator and at least one of the plurality of reflectors to be decoupled from the mechanical actuator, wherein the mechanical actuator is coupled to the selected ones of the plurality of reflectors in the first actuator position and wherein the mechanical actuator moves the selected ones of the plurality of reflectors from the respective first reflector positions to the respective second reflector positions when the mechanical actuator moves from the first mechanical actuator position to the second mechanical actuator position. Related methods are also discussed.

Claims

1. A microelectromechanical optical cross-connect switch that switches optical energy from an input of the microelectromechanical optical cross-connect switch to an output of the microelectromechanical optical cross-connect switch, the microelectromechanical optical cross-connect switch comprising:

a substrate

a plurality of reflectors, on the substrate, wherein the each of the plurality of reflectors is movable to at least one of a respective first reflector position along an optical beam path from an input of the microelectromechanical optical cross-connect switch to an output thereof and a respective second reflector position outside the optical beam path;

a mechanical actuator that is movable to at least one of a first mechanical actuator position and a second mechanical actuator position; and

a selector that selectively couples at least one of the plurality of reflectors to the mechanical actuator such that the at least one of the plurality of reflectors moves from the first reflector position to the second reflector position when the mechanical actuator moves from the first mechanical actuator position to the second mechanical actuator position.

2. A microelectromechanical optical cross-connect switch according to claim 1, wherein the selector selectively decouples at least a second one of the plurality of reflectors from the mechanical actuator so that the at least second one of the plurality of reflectors remains in the first reflector position when the mechanical actuator moves from the first mechanical actuator position to the second mechanical actuator position.

3. A microelectromechanical optical cross-connect switch according to claim 1, wherein the mechanical actuator moves from the first to the second mechanical actuator position in a direction of mechanical actuator movement that is substantially perpendicular to the substrate.

4. A microelectromechanical optical cross-connect switch according to claim 1, wherein the first and second mechanical actuator positions define a plane that is substantially parallel to the substrate.

5. A microelectromechanical optical cross-connect switch according to claim 1 further comprising:

a plurality of flexible elements, on the substrate, a respective one of the plurality of flexible elements having a first portion attached to the substrate and a second portion, spaced-apart from the first portion, attached to a respective one of the plurality of reflectors, wherein the respective one of the plurality of flexible elements allows the attached respective one of the plurality of reflectors to move between the first and second reflector positions.

6. A microelectromechanical optical cross-connect switch according to claim 5, wherein the respective one of the plurality of flexible elements includes a third portion spaced-apart from the first and second portions and attached to the substrate.

7. A microelectromechanical optical cross-connect switch according to claim 1 further comprising:

a first flexible element attached to a respective one of the plurality of reflectors and the substrate, wherein the respective one of the plurality of reflectors is coupled to the mechanical actuator and moves when the mechanical actuator moves from the first mechanical actuator, position to the second mechanical actuator position; and

a second flexible element attached to a respective second one of the plurality of reflectors and the substrate, wherein the respective second one of the plurality reflectors is decoupled from the, mechanical actuator and does not move when the mechanical actuator moves from the first mechanical actuator position to the second mechanical actuator position.

8. A microelectromechanical optical cross-connect switch according to claim 7, wherein the first flexible element remains outside the optical beam path when the respective one of the plurality of reflectors is moved to the second reflector position.

9. A microelectromechanical optical cross-connect switch according to claim 7, wherein the first flexible element remains substantially outside the optical beam path when the respective one of the plurality of reflectors is moved to the second reflector position.

10. A microelectromechanical optical cross-connect switch according to claim 7, wherein the first flexible element includes a first portion attached to the substrate and a second portion, spaced-apart from the first portion, attached to the respective one of the plurality of reflectors, further comprising:

a third flexible element, on the substrate, spaced-apart from the first flexible element, the third flexible element having a first portion attached to the substrate and a second portion, spaced-apart from the first portion, attached to the respective one of the plurality of reflectors, wherein the third flexible element moves when the mechanical actuator moves from the first mechanical actuator position to the second mechanical actuator position.

11. A microelectromechanical optical cross-connect switch according to claim 10, wherein the third flexible element is located substantially outside the optical beam path when the respective one of the plurality of reflectors is moved to the second reflector position.

12. A microelectromechanical optical cross-connect switch according to claim 7, wherein at least one of the first and second flexible elements comprises a u-shaped zig-zag pattern.

13. A microelectromechanical optical cross-connect switch according to claim 7, wherein at least one of the first and second flexible elements comprises a closed rectangular pattern.

14. A microelectromechanical optical cross-connect switch according to claim 7, wherein at least one of the first and second flexible elements extends in a direction substantially perpendicular to the substrate when the mechanical actuator moves from the first to the second mechanical actuator position.

15. A microelectromechanical optical cross-connect switch according to claim 7, wherein at least one of the first and second plurality of flexible elements extends in a direction substantially parallel to the substrate when the mechanical actuator moves from the first to the second mechanical actuator position.

16. A microelectromechanical optical cross-connect switch according to claim 1, further comprising:

a plurality of trenches in the substrate adjacent the plurality of reflectors.

17. A microelectromechanical optical cross-connect switch according to claim 5, further comprising:

a plurality of trenches in the substrate opposite the plurality of reflectors, wherein each of the plurality of flexible elements extends opposite the associated one of the plurality of trenches from the substrate to the associated one of plurality of reflectors.

18. A microelectromechanical optical cross-connect switch according to claim 1, wherein the mechanical actuator comprises a conductive plate that is moved between the first and second mechanical actuator positions via at least one of an inductively driven servo and a stepper motor.

19. A microelectromechanical optical cross-connect switch according to claim 1, wherein the selector comprises a plurality of conductors that conduct a voltage level to the selected ones of the plurality of reflectors to couple the selected ones of the plurality of reflectors to the mechanical actuator.

20. A microelectromechanical optical cross-connect switch that switches optical energy from an input of the microelectromechanical optical cross-connect switch to an output of the microelectromechanical optical cross-connect switch, the microelectromechanical optical cross-connect switch comprising:

a substrate;

a reflector, on the substrate, wherein the reflector is movable to at least one of a first reflector position along an optical beam path from an associated input of the microelectromechanical optical cross-connect switch to an associated output thereof and a second reflector position outside the optical beam path;

a mechanical actuator that is movable to at least one of a first mechanical actuator position and a second mechanical actuator position; and

a selector that selects a reflector to be coupled to the mechanical actuator, wherein a selected reflector is coupled to the mechanical actuator in the first mechanical actuator position so that the mechanical actuator moves the reflector from the first reflector position to the second position when the mechanical actuator moves from the first mechanical actuator position to the second mechanical actuator position.

21. A microelectromechanical optical cross-connect switch according to claim 20, wherein the selector selects a reflector to be decoupled from the mechanical actuator and remain in the first reflector position when the mechanical actuator moves from the first mechanical actuator position to the second mechanical actuator position.

22. A microelectromechanical optical cross-connect switch according to claim 20, wherein the mechanical actuator moves from the first to the second mechanical actuator position in a direction of mechanical actuator movement that is substantially perpendicular to the substrate.

23. A microelectromechanical optical cross-connect switch according to claim 20, wherein the first and second mechanical actuator positions define a plane that is substantially parallel to the substrate.

24. A microelectromechanical optical cross-connect switch according to claim 20 further comprising:

a flexible element, on the substrate, the flexible element having a first portion attached to the substrate and a second portion, spaced-apart from the first portion, attached to the reflector, wherein the flexible element allows the reflector to move between the first and second reflector positions.

25. A microelectromechanical optical cross-connect switch according to claim 24, wherein the flexible element includes a third portion spaced-apart from the first and second portions and attached to the substrate.

26. A microelectromechanical optical cross-connect switch according to claim 20 further comprising:

a second flexible element, on the substrate, the second flexible element having a respective first portion attached to the substrate and a respective second portion, spaced-apart from the first portion, attached to the reflector, wherein the second flexible element extends when the mechanical actuator moves from the first mechanical actuator position to the second mechanical actuator position.

27. A microelectromechanical optical cross-connect switch according to claim 26, wherein the first and second flexible elements are located outside the optical beam path when the reflector is in the second reflector position.

28. A microelectromechanical optical cross-connect switch according to claim 26, wherein at least one of the first and second flexible elements comprises a u-shaped zig-zag flexible element.

29. A microelectromechanical optical cross-connect switch according to claim 26, wherein at least one of the first and second flexible elements comprises a closed rectangular shape.

30. A microelectromechanical optical cross-connect switch according to claim 26, wherein at least one. of the first and second flexible elements extends in a direction substantially perpendicular to the substrate when the mechanical actuator moves from the first to the second mechanical actuator position.

31. A microelectromechanical optical cross-connect switch according to claim 26, wherein at least one of the first and second flexible elements extends in a direction substantially parallel to the substrate when the mechanical actuator moves from the first to the second mechanical actuator position.

32. A microelectromechanical optical cross-connect switch according to claim 20, further comprising:

a trench in the substrate adjacent the reflector, wherein a trench width and length are greater than a reflector width and length.

33. A microelectromechanical optical cross-connect switch according to claim 20, wherein the mechanical actuator comprises a conductive plate that is moved between the first and second mechanical actuator positions via at least one of an inductively driven servo and a stepper motor least.

34. A microelectromechanical optical cross-connect switch that switches optical energy from an input of the microelectromechanical optical cross-connect switch to an output of the microelectromechanical optical cross-connect switch, the microelectromechanical optical cross-connect switch comprising:

a substrate;

a plurality of reflectors, on the substrate, wherein at least one of the plurality of reflectors is movable to at least one of a first reflector position along an optical beam path from an associated input of the microelectromechanical optical cross-connect switch to an associated output thereof and a second reflector position outside the optical beam path;

a mechanical actuator that moves selected ones of the plurality of reflectors from respective first reflector positions to respective second reflector positions; and

a selector that selects ones of the plurality of reflectors to remain in the second reflector position when the mechanical actuator moves from the second mechanical actuator position to the first mechanical actuator position.

35. A microelectromechanical optical cross-connect switch according to claim 34, wherein the selector comprises a plurality of conductors electrically coupled to the plurality of reflectors, wherein the selected ones of the plurality of conductors conduct a clamping voltage level to the selected ones of the plurality of reflectors to maintain the selected ones of the plurality of reflectors in the respective second reflector positions when the mechanical actuator moves from the second mechanical actuator position to the first mechanical actuator position.

36. A microelectromechanical optical cross-connect switch that switches optical energy from an input of the microelectromechanical optical cross-connect switch to an output of the microelectromechanical optical cross-connect switch, the microelectromechanical optical cross-connect switch comprising:

a substrate;

a plurality of reflectors, on the substrate, wherein at least one of the plurality of reflectors is movable to at least one of a first reflector position along an optical beam path from an associated input of the microelectromechanical optical cross-connect switch to an associated output thereof and a second reflector position outside the optical beam path;

a mechanical actuator that moves selected ones of the plurality of reflectors from respective first reflector positions to respective second reflector positions; and

a selector that selects ones of the plurality of reflectors to be coupled to the mechanical actuator and at least one of the plurality of reflectors to be decoupled from the mechanical actuator, wherein the mechanical actuator is coupled to the selected ones of the plurality of reflectors in the first actuator position and wherein the mechanical actuator moves the selected ones of the plurality of reflectors from the respective first reflector positions to the respective second reflector positions when the mechanical actuator moves from the first mechanical actuator position to the second mechanical actuator position.

37. A microelectromechanical optical cross-connect switch according to claim 36, wherein the selected at least one of the plurality of reflectors remains in the first reflector position when the mechanical actuator moves from the first mechanical actuator position to the second mechanical actuator position.

38. A microelectromechanical optical cross-connect switch according to claim 36, wherein the first and second mechanical actuator positions define a plane that is substantially perpendicular to the substrate.

39. A microelectromechanical optical cross-connect switch according to claim 36, wherein the first and second mechanical actuator positions define a plane that is substantially parallel to the substrate.

40. A microelectromechanical optical cross-connect switch according to claim 36 further comprising:

a plurality of flexible elements, on the substrate, each of the plurality of flexible elements having a first portion attached to the substrate and a second portion, spaced-apart from the first portion, attached to one of the plurality of reflectors, wherein each of the plurality of flexible elements allows the attached one of the plurality of reflectors to move between the first and second reflector positions.

41. A microelectromechanical optical cross-connect switch according to claim 40, wherein each of the plurality of flexible elements includes a third portion spaced-apart from the first and second portions and attached to the substrate.

42. A microelectromechanical optical cross-connect switch according to claim 36 further comprising:

a plurality of flexible elements, on the substrate, each of the plurality of flexible elements having a first portion attached to the substrate and a second portion, spaced-apart from the first portion attached to one of the plurality of reflectors, wherein ones of the plurality of flexible elements attached to the selected ones of the plurality of reflectors move when the mechanical actuator moves from the first mechanical actuator position to the second mechanical actuator position and at least one of the plurality of flexible elements attached to the selected at least one of the plurality of reflectors holds the selected at least one of the plurality of reflectors in the first reflector position when the mechanical actuator moves from the first mechanical actuator position to the second mechanical actuator position.

43. A microelectromechanical optical cross-connect switch according to claim 42, wherein the ones of the plurality of flexible elements attached to the at least one of the plurality of reflectors are located outside the optical beam path when the at least one of the plurality of reflectors is moved to the second reflector position.

44. A microelectromechanical optical cross-connect switch according to claim 42, wherein the ones of the plurality of flexible elements attached to the at least one of the plurality of reflectors are located substantially outside the optical beam path when the at least one of the plurality of reflectors is moved to the second reflector position.

45. A microelectromechanical optical cross-connect switch according to claim 41 further comprising:

a plurality of second flexible elements, on the substrate, spaced-apart from the plurality of first flexible elements, each of the plurality of second flexible elements having a first portion attached to the substrate and a second portion, spaced-apart from the first portion, attached to one of the plurality of reflectors, wherein ones of the plurality of second flexible elements attached to the selected ones of the plurality of reflectors move when the mechanical actuator moves from the first mechanical actuator position to the second mechanical actuator position and at least one of the plurality of second flexible elements attached to the selected at least one of the plurality of reflectors holds the selected at least one of the plurality of reflectors in the first reflector position when the mechanical actuator moves from the first mechanical actuator position to the second mechanical actuator position.

46. A microelectromechanical optical cross-connect switch according to claim 45, wherein the ones of the plurality of second flexible elements attached to the at least one of the plurality of reflectors are located substantially outside the optical beam path when the at least one of the plurality of reflectors is moved to the second reflector position.

47. A microelectromechanical optical cross-connect switch according to claim 41, wherein at least one of the plurality of flexible elements comprises a u-shaped zig-zag flexible element.

48. A microelectromechanical optical cross-connect switch according to claim 41, wherein at least one of the plurality of flexible elements comprises a w-shaped zig-zag flexible element.

49. A microelectromechanical optical cross-connect switch according to claim 41, wherein at least one of the plurality of flexible elements extends in a direction substantially perpendicular to the substrate when the mechanical actuator moves from the first to the second mechanical actuator position.

50. A microelectromechanical optical cross-connect switch according to claim 41, wherein at least one of the plurality of flexible elements extends in a direction substantially parallel to the substrate when the mechanical actuator moves from the first to the second mechanical actuator position.

51. A microelectromechanical optical cross-connect switch according to claim 36, further comprising:

a plurality of trenches in the substrate opposite the plurality of reflectors.

52. A microelectromechanical optical cross-connect switch according to claim 40, further comprising:

a plurality of trenches in the substrate opposite the plurality of reflectors, wherein each of the plurality of flexible elements extends opposite the associated one of the plurality of trenches from the substrate to the associated one of plurality of reflectors.

53. A microelectromechanical optical cross-connect switch according to claim 36, wherein the mechanical actuator comprises a conductive plate that is moved between the first and second mechanical actuator positions via at least one of an inductively driven servo and a stepper motor least.

54. A microelectromechanical optical cross-connect switch according to claim 36, wherein the selector comprises a conductor that conducts a plurality of voltage levels to the selected ones of the plurality of reflectors to couple the selected ones of the plurality of reflectors to the mechanical actuator.

55. A method for switching optical energy from an input of a microelectromechanical optical cross-connect switch to an output thereof, the method comprising the steps of:

coupling at least one of a plurality of reflectors at respective first reflector positions to a mechanical actuator along an optical beam path from an associated input of the microelectromechanical optical cross-connect switch to an associated output thereof;

moving the mechanical actuator from a first mechanical actuator position to a second mechanical actuator position to move the at least one of the plurality of reflectors to respective second reflector positions outside the optical beam path; and

decoupling at least one of the plurality of reflectors from the mechanical actuator in the first mechanical actuator position so that the at least one of the plurality of reflectors remains in the first reflector position along the optical beam path when the mechanical actuator moves from the first to the second mechanical actuator position.

56. A method according to claim 55, wherein the step of moving comprises the step of moving the mechanical actuator along a path substantially parallel to a substrate of the microelectromechanical optical cross-connect switch.

57. A method according to claim 55, wherein the step of moving comprises the step of moving the mechanical actuator along a path substantially perpendicular to a substrate of the microelectromechanical optical cross-connect switch.

63. A method according to claim 55, further comprising the step of:

transmitting optical energy from the input to the output along the optical beam path.

58. A method for switching optical energy from an input of a microelectromechanical optical cross-connect switch to an output thereof, the method comprising the steps of:

coupling at least one of a plurality of reflectors at respective first reflector positions to a mechanical actuator along an optical beam path from an associated input of the microelectromechanical optical cross-connect switch to an associated output thereof;

moving the mechanical actuator from a first mechanical actuator position to a second mechanical actuator position to move the at least one of the plurality of reflectors to respective second reflector positions outside the optical beam path;

moving the mechanical actuator from the second to the first mechanical actuator position; and

decoupling the coupled ones of the plurality of reflectors from the mechanical actuator in the first mechanical actuator position.

59. A method for switching optical energy from an input of a microelectromechanical optical cross-connect switch to an output thereof, the method comprising the steps of:

coupling at least one of a plurality of reflectors at respective first reflector positions to a mechanical actuator along an optical beam path from an associated input of the microelectromechanical optical cross-connect switch to an associated output thereof,

moving the mechanical actuator from a first mechanical actuator position to a second mechanical actuator position to move the at least one of the plurality of reflectors to respective second reflector positions outside the optical beam path; and

decoupling the coupled ones of the plurality of reflectors from the mechanical actuator in the second mechanical actuator position.

60. A method for switching optical energy from an input of a microelectromechanical optical cross-connect switch to an output thereof, the method comprising the steps of:

coupling at least one of a plurality of reflectors at respective first reflector positions to a mechanical actuator along an optical beam path from an associated input of the microelectromechanical optical cross-connect switch to an associated output thereof, and

moving the mechanical actuator from a first mechanical actuator position to a second mechanical actuator position to move the at least one of the plurality of reflectors to respective second reflector positions outside the optical beam path, wherein the step of coupling comprises the step of applying a clamping voltage level to the ones of the plurality of reflectors to electrostatically couple the ones of the plurality of reflectors to the mechanical actuator.

61. A method for switching optical energy from an input of a microelectromechanical optical cross-connect switch to an output thereof, the method comprising the steps of:

coupling at least one of a plurality of reflectors at respective first reflector positions to a mechanical actuator along an optical beam path from an associated input of the microelectromechanical optical cross-connect switch to an associated output thereof; and

moving the mechanical actuator from a first mechanical actuator position to a second mechanical actuator position to move the at least one of the plurality of reflectors to respective second reflector positions outside the optical beam path, wherein the step of moving comprises the steps of moving the mechanical actuator from the first to the second mechanical actuator position to contact ones of the plurality of reflectors to move the contacted ones of the plurality of reflectors from the first reflector position substantially perpendicular to the optical beam path to the second reflector position substantially parallel to the optical beam path and clamping ones of the plurality of reflectors in the second reflector position.

62. A method according to claim 61, further comprising the steps of:

moving the mechanical actuator from the second mechanical actuator position; and

allowing selected ones of the plurality of reflectors to move from the second to the first reflector position.