Flexible, modular, compact fiber switch improvements

• US 6,694,072 B1
• Filed: 01/11/2002
• Issued: 02/17/2004
• Est. Priority Date: 07/21/1999
• Status: Expired due to Fees

• Current Assignee: RPX Clearinghouse LLC (RPX Corporation)
• Original Assignee: Xros, Inc. (Nortel Networks Corporation)
• Inventors: Foster, Jack D., Slater, Timothy G., Schuman, Marc R., Clark, Steven M., Neukermans, Armand P., Calmes, Sam
• Primary Examiner(s): Kim, Ellen E.
• Application Number:
  US10/031,159
• Time in Patent Office: 767 Days
• Field of Search: 385/16, 385/18, 385/20, 385/24
• US Class Current: 385/18
• CPC Class Codes: G02B 26/0841 the reflecting element being moved or deformed by electrostatic means
• CPC Class Codes: G02B 26/085 the reflecting means being moved or deformed by electromagnetic means
• 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 6/327 with angled interfaces to reduce reflections
• 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 6/3582 Housing means or package or arranging details of the switching elements, e.g. for thermal isolation
• 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
• CPC Class Codes: G02B 6/3644 the coupling means being through-holes or wall apertures
• CPC Class Codes: G02B 6/3656 the additional structures being micropositioning, with microactuating elements for fine adjustment, or restricting movement, into two dimensions, e.g. cantilevers, beams, tongues or bridges with associated MEMs
• CPC Class Codes: G02B 6/3672 with fibres arranged in a regular matrix array
• CPC Class Codes: G02B 6/3692 with surface micromachining involving etching, e.g. wet or dry etching steps surface micromachining involving subtractive techniques B81C1/00055
• CPC Class Codes: H04Q 11/0005 Switch and router aspects
• CPC Class Codes: H04Q 2011/003 using switches based on microelectro-mechanical systems [MEMS]
• CPC Class Codes: H04Q 2011/0039 Electrical control

Abstract

A fiber optic switch (400) includes a fiber optic switching module (100) that receives and fixes ends (104) of optical fibers (106). The module (100) includes numerous reflective light beam deflectors (172) arranged in a V-shape which may be selected as pairs for coupling a beam of light (108) between a pair of optical fibers (106). The module (100) also produces orientation signals from each deflector (172) which indicate its orientation. A portcard (406) supplies drive signals to the module (100) for orienting at least one deflector (172). The portcard (406) also receives the orientation signals produced by that deflector (172) together with coordinates that specify an orientation for the deflector (172). The portcard (406) compares the received coordinates with the orientation signals and adjusts the drive signals supplied to the module (100) to reduce any difference between the received coordinates and the orientation signals. The switch (400) also employs optical alignment to precisely orient pairs deflectors (172) coupling a beam of light (108) between optical fibers (106).

Claims

1. A fiber optic switching module comprising:

a) a first and a second group of collimator receptacles which are separated from each other at opposite ends of a free space optical path, and each of which collimator receptacles is respectively adapted for receiving and fixing an optical fiber collimator assembly;

that in turn receives and fixes an end of an optical fiber, and

which is adapted for emitting a quasi-collimated beam of light into the optical path;

b) a first and a second set of reflective light beam deflectors that are disposed in a V-shaped arrangement within the optical path between the groups of collimator receptacles, each of the light beam deflectors being;

associated with one of the optical fiber collimator assemblies receivable in the collimator receptacles;

located so the quasi-collimated beam of light emittable from the associated optical fiber collimator assembly impinges upon the light beam deflector to be reflected therefrom; and

energizable by drive signals supplied to said fiber optic switching module to be oriented for reflecting the quasi-collimated beam of light emittable from the associated optical fiber collimator assembly to also reflect off a selected light beam deflector; and

c) a mirror disposed along the optical path between said sets of light beam deflectors upon which quasi-collimated beams of light impinge;

whereby a pair of light beam deflectors when selected and oriented by the drive signals supplied thereto, establish an optical coupling for at least one quasi-collimated beam of light between a pair of optical fiber collimator assemblies one of which is fixable in any one of said collimator receptacles and another optical fiber collimator assembly fixable in any other of said collimator receptacles.

2. The fiber optic switching module of claim 1 wherein the first group includes only one collimator receptacle and the second group includes the remaining collimator receptacles whereby the fiber optic switching module establishes the optical coupling between one optical fiber collimator assembly fixable in the single collimator receptacle and a selected one of the optical fiber collimator assemblies fixable in the second group of collimator receptacles.

3. The fiber optic switching module of claim 1 wherein individual collimator receptacles are conically-shaped and are adapted to receive a mating, conically-shaped optical fiber collimator assembly.

4. The fiber optic switching module of claim 1 further comprising environmental housing that encloses the optical path through which the beams of light propagate.

5. The fiber optic switching module of claim 4 wherein the environmental housing provides temperature regulation for maintaining a stable operating environment for the fiber optic switching module.

6. The fiber optic switching module of claim 4 wherein dry gas flows through the environmental housing to hinder moisture from condensing within the fiber optic switching module.

7. The fiber optic switching module of claim 4 wherein the environmental housing is pressurized to exclude atmosphere surrounding the environmental housing from entering the fiber optic switching module.

8. The fiber optic switching module of claim 4 wherein the environmental housing includes a nonsaturable microdryer to hinder moisture from condensing within the fiber optic switching module.

9. The fiber optic switching module of claim 4 wherein a wall of the environmental housing is pierced by an electrical feed-through through which the drive signals pass.

10. The fiber optic switching module of claim 1 wherein, when light beam deflectors are un-energized, beams of light reflecting therefrom substantially converge in one dimension (“

1D”

).

11. The fiber optic switching module of claim 1 wherein, when light beam deflectors are un-energized, beams of light reflecting therefrom substantially converge in two dimensions (“

2D”

).

12. The fiber optic switching module of claim 11 wherein orientation of said collimator receptacles effects convergence of beams of light in a first dimension, and orientation of said light beam deflectors when un-energized effects convergence in a second dimension.

13. The fiber optic switching module of claim 1 wherein, when light beam deflectors of the first or of the second set are un-energized, the beams of light reflecting therefrom substantially converge at a point that is located behind a juncture of said sets of light beam deflectors.

14. The fiber optic switching module of claim 1 wherein, when light beam deflectors of the first or of the second set are un-energized, the beams of light reflecting therefrom substantially converge at a point that is located at a juncture of said sets of light beam deflectors.

15. The fiber optic switching module of claim 1 wherein light beam deflectors of the first or of the second set that require the greatest movement in reflecting a beam of light to any of the light beam deflectors in the second or in the first set exhibit substantially equal clockwise and counter-clockwise rotation angles from an un-energized orientation of such light beam deflectors.

16. The fiber optic switching module of claim 1 wherein light beam deflectors of the first or of the second set that require the greatest movement in reflecting a beam of light to any of the light beam deflectors in the second or in the first set:

rotate about two non-parallel axes; and

exhibit substantially equal clockwise and counter-clockwise rotation angles about at least one of the axes from an un-energized orientation of such light beam deflectors.

17. The fiber optic switching module of claim 1 wherein light beam deflectors of the first or of the second set that require the greatest movement in reflecting a beam of light to any of the light beam deflectors in the second or in the first set exhibit substantially equal bi-polar rotation angles from an un-energized orientation of such light beam deflectors.

18. The fiber optic switching module of claim 1 wherein light beam deflectors of the first or of the second set that require the greatest movement in reflecting a beam of light to any of the light beam deflectors in the second or in the first set:

rotate about two non-parallel axes; and

exhibit substantially equal bi-polar rotation angles about at least one of the axes from an un-energized orientation of such light beam deflectors.

19. The fiber optic switching module of claim 1 wherein light beam deflectors of the first or of the second set that require the greatest movement in reflecting a beam of light to any of the light beam deflectors in the second or in the first set exhibit minimum rotation angles from an un-energized orientation of such light beam deflectors.

20. The fiber optic switching module of claim 1 wherein orientation of only the collimator receptacles effects convergence of beams of light.

21. The fiber optic switching module of claim 1 wherein orientation of only said light beam deflectors when un-energized effects convergence of beams of light.

22. The fiber optic switching module of claim 1 wherein drive signals supplied to the fiber optic switching module for energizing orientation of each light beam deflector respond to a signal produced by an orientation sensor that is coupled to the light beam deflector.

23. The fiber optic switching module of claim 1 wherein drive signals supplied to the fiber optic switching module for energizing orientation of each light beam deflector respond to a signal produced by an orientation sensor that is independent of the beam of light reflectable therefrom.

24. The fiber optic switching module of claim 1 wherein said light beam deflectors are respectively supported from a frame by torsional hinges, and each frame, torsional hinges and light beam deflector are fabricated from single crystal silicon.

25. A fiber optic switching module comprising:

a first and a second group of optical fiber receptacles, said groups of optical fiber receptacles being separated from each other at opposite ends of a free space optical path, and each optical fiber receptacle being adapted for receiving and fixing an end of an optical fiber;

lenses one of which is fixed respectively at each of the optical fiber receptacles of the first and second groups so the end of the optical fiber fixable in that optical fiber receptacle is juxtaposed with said lens fixed thereat, each said lens being adapted for receiving a beam of light emittable from the juxtaposed end of the optical fiber and for emitting a quasi-collimated beam of light into the optical path of the fiber optic switching module;

c) a first and a second set of reflective light beam deflectors that are disposed in a V-shaped arrangement within the optical path between the groups of optical fiber receptacles, each of the light beam deflectors respectively being;

associated with one of said lenses fixed at each of the optical fiber receptacles;

located so the quasi-collimated beam of light emittable from said associated lens impinges upon the light beam deflector to be reflected therefrom; and

energizable by drive signals supplied to said fiber optic switching module to be oriented for reflecting the quasi-collimated beam of light emittable from said associated lens to also reflect off a selected light beam deflector; and

d) a mirror disposed along the optical path between said sets of light beam deflectors upon which quasi-collimated beams of light impinge;

whereby a pair of light beam deflectors when selected and oriented by the drive signals supplied thereto, establish an optical coupling for at least one quasi-collimated beam of light between a pair of lenses respectively fixable at any one of said optical fiber receptacles and another lens fixable at any other of the optical fiber receptacles.

26. The fiber optic switching module of claim 25 wherein the first group includes only one optical fiber receptacle and the second group includes the remaining optical fiber receptacles whereby the fiber optic switching module establishes the optical coupling between one lens fixed at the single optical fiber receptacle and one of said lenses fixed at the second group of optical fiber receptacles.

27. The fiber optic switching module of claim 25 further comprising environmental housing that encloses the optical path through which the beams of light propagate.

28. The fiber optic switching module of claim 27 wherein the environmental housing provides temperature regulation for maintaining a stable operating environment for the fiber optic switching module.

29. The fiber optic switching module of claim 27 wherein dry gas flows through the environmental housing to hinder moisture from condensing within the fiber optic switching module.

30. The fiber optic switching module of claim 27 wherein the environmental housing is pressurized to exclude atmosphere surrounding the environmental housing from entering the fiber optic switching module.

31. The fiber optic switching module of claim 27 wherein the environmental housing includes a nonsaturable microdryer to hinder moisture from condensing within the fiber optic switching module.

32. The fiber optic switching module of claim 27 wherein a wall of the environmental housing is pierced by an electrical feed-through through which the drive signals pass.

33. The fiber optic switching module of claim 25 wherein, when light beam deflectors are un-energized, beams of light reflecting therefrom substantially converge in 1D.

34. The fiber optic switching module of claim 25 wherein, when light beam deflectors are un-energized, beams of light reflecting therefrom substantially converge in 2D.

35. The fiber optic switching module of claim 34 wherein orientation of said optical fiber receptacles and said lenses effects convergence of beams of light in a first dimension, and orientation of said light beam deflectors when un-energized effects convergence in a second dimension.

36. The fiber optic switching module of claim 25 wherein, when light beam deflectors of the first or of the second set are un-energized, the beams of light reflecting therefrom substantially converge at a point that is located behind a juncture of said sets of light beam deflectors.

37. The fiber optic switching module of claim 25 wherein, when light beam deflectors of the first or of the second set are un-energized, the beams of light reflecting therefrom substantially converge at a point that is located at a juncture of said sets of light beam deflectors.

38. The fiber optic switching module of claim 25 wherein light beam deflectors of the first or of the second set that require the greatest movement in reflecting a beam of light to any of the light beam deflectors in the second or in the first set exhibit substantially equal clockwise and counter-clockwise rotation angles from an un-energized orientation of such light beam deflectors.

39. The fiber optic switching module of claim 25 wherein light beam deflectors of the first or of the second set that require the greatest movement in reflecting a beam of light to any of the light beam deflectors in the second or in the first set:

rotate about two non-parallel axes; and

exhibit substantially equal clockwise and counter-clockwise rotation angles about at least one of the axes from an un-energized orientation of such light beam deflectors.

40. The fiber optic switching module of claim 25 wherein light beam deflectors of the first or of the second set that require the greatest movement in reflecting a beam of light to any of the light beam deflectors in the second or in the first set exhibit substantially equal bi-polar rotation angles from an un-energized orientation of such light beam deflectors.

41. The fiber optic switching module of claim 25 wherein light beam deflectors of the first or of the second set that require the greatest movement in reflecting a beam of light to any of the light beam deflectors in the second or in the first set:

rotate about two non-parallel axes; and

exhibit substantially equal bi-polar rotation angles about at least one of the axes from an un-energized orientation of such light beam deflectors.

42. The fiber optic switching module of claim 25 wherein light beam deflectors of the first or of the second set that require the greatest movement in reflecting a beam of light to any of the light beam deflectors in the second or in the first set exhibit minimum rotation angles from an un-energized orientation of such light beam deflectors.

43. The fiber optic switching module of claim 25 wherein orientation of only said optical fiber receptacles and said lenses effects convergence of beams of light.

44. The fiber optic switching module of claim 25 wherein orientation of only said light beam deflectors when un-energized effects convergence of beams of light.

45. The fiber optic switching module of claim 25 wherein drive signals supplied to the fiber optic switching module for energizing orientation of each light beam deflector respond to a signal produced by an orientation sensor that is coupled to the light beam deflector.

46. The fiber optic switching module of claim 25 wherein drive signals supplied to the fiber optic switching module for energizing orientation of each light beam deflector respond to a signal produced by an orientation sensor that is independent of the beam of light reflectable therefrom.

47. The fiber optic switching module of claim 25 wherein said light beam deflectors are respectively supported from a frame by torsional hinges, and each frame, torsional hinges and light beam deflector are fabricated from single crystal silicon.

48. The fiber optic switching module of claim 25 wherein ends of optical fibers receivable into optical fiber receptacles emit a beam of light at an angle with respect to a center line of the optical fiber, and first faces of lenses respectively associated therewith are oriented at an oblique angle with respect to a longitudinal axis of the lens so that within each lens the beam of light is substantially aligned with the longitudinal axis of the lens.

49. The fiber optic switching module of claim 48 herein each lens has a focal point located substantially at the obliquely angled face thereof, and the end of the optical fiber receivable into the optical fiber receptacle associated therewith is positioned one Raleigh range of the beam of light from the obliquely angled face.

50. The fiber optic switching module of claim 48 wherein optical fibers receivable into optical fiber receptacles are duplex optical fibers and lenses respectively associated therewith further have a second face that:

is oriented at an oblique angle with respect to the longitudinal axis of each lens; and

intersects with and is not parallel to the first face thereof,

so that within each lens two beams of light, respectively exiting or entering the end of the duplex optical fiber respectively associated therewith at differing angles with respect to the center line of the optical fiber, are substantially aligned with the longitudinal axis of the lens.

51. The fiber optic switching module of claim 50 wherein two beams of light propagate through the duplex optical fiber in opposite directions.

52. The fiber optic switching module of claim 50 wherein two beams of light propagate through the duplex optical fiber in a single direction.

53. The fiber optic switching module of claim 25 wherein lenses included in the fiber optic switching module are respectively formed with a smaller diameter outer surface which is disposed nearer to the end of said optical fiber receivable into the optical fiber receptacle associated therewith, the lenses also being formed with a larger diameter outer surface which is disposed further from the end of said optical fiber receivable into the optical fiber receptacle associated therewith than the smaller diameter outer surface of the lens.