Optical switch with internal monitoring

• US 6,792,177 B2
• Filed: 03/12/2001
• Issued: 09/14/2004
• Est. Priority Date: 03/12/2001
• Status: Expired due to Term

• Current Assignee: Calient Networks Incorporated
• Original Assignee: Calient Networks Incorporated
• Inventors: Fant, Walter Joseph, Blumenthal, Daniel Jacob, Welsh, David Edward, Helkey, Roger Jonathan, Keating, Adrian
• Primary Examiner(s): Duverne, Jean F.
• Application Number:
  US09/805,528
• Publication Number:
  US 20020126949A1
• Time in Patent Office: 1,282 Days
• Field of Search: 385/18, 385/20, 385/16, 385/17, 385/15, 385/14, 385/33, 385/47, 385/52, 385/73, 359/290, 359/291, 359/298
• US Class Current: 385/18
• CPC Class Codes: G02B 6/3512 the optical element being reflective, e.g. mirror
• 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 6/359 of the position of the moving element itself during switching, i.e. without monitoring the switched beams

Abstract

The invention provides an optical switch comprising a housing, an input optical fiber, a mirror substrate, an input pivoting mirror, an output optical fiber, a first optical splitter, and a first optical detector. The input optical fiber propagates a light beam and is secured to the housing. The mirror substrate is secured to the housing. The input pivoting mirror is located in a path of the light beam after leaving the input optical fiber. The input pivoting mirror is pivotally secured to the mirror substrate. Pivoting of the mirror relative to the mirror substrate alters an angle with which the light beam is reflected therefrom. The output optical fiber is secured to the housing and has an end through which the light beam enters after being reflected by the input pivoting mirror. The first optical splitter is located in a path of the light beam after leaving the input optical fiber. The first optical splitter splits the light beam into a first propagated portion and a first monitoring portion. The first propagated portion is propagated through the output optical fiber and the first monitoring portion is detected by the first optical detector.

Claims

1. An optical switch, comprising:

an input optical fiber to propagate a light beam;

a mirror substrate;

an input pivoting mirror located in a path of the light beam after leaving the input optical fiber, the input pivoting mirror being pivotally secured to the mirror substrate, pivoting of the input pivoting mirror relative to the mirror substrate altering an angle with which the light beam is reflected therefrom;

an output optical fiber, having an end through which the light beam enters after being reflected by the input pivoting mirror;

a first optical splitter located in a path of the light beam after leaving the input optical fiber; and

a first optical detector, the first optical splitter splitting the light beam into a first propagated portion and a first monitoring portion, the first propagated portion being propagated through the output optical fiber and the first monitoring portion being received by the first optical detector, wherein the first optical splitter splits the light beam at a location after leaving the input optical fiber, and the first optical splitter is a partially transmissive optical splitter mirror that propagates one, and reflects the other one, of the first propagated portion and the first monitoring portion.

2. The optical switch of claim 1 wherein the first optical splitter splits the light beam after being reflected by the input pivoting mirror.

3. The optical switch of claim 1 wherein the first optical splitter splits the light beam after entering the output optical fiber.

4. The optical switch of claim 3 wherein the first optical splitter is an optical splitting coupler located in the output optical fiber, further comprising:

a monitoring optical fiber connected to the coupler so that the first propagated portion propagates from the coupler through the output optical fiber, and the first monitoring portion propagates through the monitoring optical fiber to the first optical detector.

5. The optical switch of claim 1 wherein the first optical splitter is an input optical splitter that splits the light beam at a location before being reflected by the input pivoting mirror, the first propagated portion being an input propagated portion, the first monitoring portion being an input monitoring portion and the first detector being an input detector, further comprising:

an output optical splitter located in a path of the light beam at a location after being reflected by the input pivoting mirror; and

an output detector, the output optical splitter splitting the input propagated portion into an output propagated portion and an output monitoring portion, the output propagated portion being propagated through the output optical fiber and the output monitoring portion being detected by the output detector.

6. The optical switch of claim 5 further comprising:

a transmissive substrate, the input optical splitter being a first, partially transmissive input optical splitter mirror, on the transmissive substrate, that propagates the input propagated portion therethrough and reflects the input monitoring portion therefrom, and the output optical splitter being an output optically spiting coupler located in the output fiber;

a monitoring optical fiber being connected to the coupler so that the output propagated portion is propagated through the output optical fiber and the output monitoring portion is propagated through the monitoring optical fiber; and

a second, reflective mirror on the transmissive substrate, that reflects the light beam, after leaving the monitoring optical fiber, towards the output optical detector.

7. The optical switch of claim 6 wherein the input propagated portion propagates through the transmissive substrate after being reflected by the input pivoting mirror and before entering the output optical fiber.

8. The optical switch of claim 1 wherein the optical detector is a photodetector that generates an electric signal dependent on an intensity of the first monitoring portion.

23. The optical switch of claim 1 further comprising:

a plurality of said detectors;

a plurality of output lines, each output line being connected to more than one of said detectors.

24. The optical switch of claim 23 wherein there are more detectors than output lines.

25. The optical switch of claim 23 further comprising:

a plurality of sample lines, each sample line being connected to a respective detector.

26. The optical switch of claim 25 wherein there are at least as many detectors as the sample lines multiplied by output lines.

27. The optical switch of claim 1 further comprising:

a first transparent component, the first optical splitter being a partially transmissive mirror layer on a surface of the first transparent component; and

a second transparent component on the partially transmissive mirror layer so that the partially transmissive mirror layer is located between the first and second transparent components.

28. The optical switch of claim 27 wherein a selected one of the first transparent components has a first surface through which the light beam enters into the selected transparent component and a second surface through which the light beam leaves the selected transparent component, the second surface being at an angle other than 90°

relative to a direction of the light beam upon reaching the second surface.

29. The optical switch of claim 28 wherein the respective light beams converge away from the second surface.

30. The optical switch of claim 29 wherein the second surface includes at least two flat sections, the light beam passing through both flat sections.

31. The optical switch of claim 29 wherein the second surface has a curvature.

32. The optical switch of claim 29 wherein the second surface forms a plurality of individual curved lenses.

33. The optical switch of claim 28 wherein the second surface forms a plurality of individual curved lenses.

34. The optical switch of claim 33 wherein a respective light beam travels through a respective individual curved lens.

35. The optical switch of claim 33 wherein one light beam passes through two of the individual curved lenses.

36. The optical switch of claim 27 further comprising a transparent housing to which the second transparent components are mounted.

37. The optical switch of claim 36 wherein the transparent housing has at least one outer surface at an angle relative to a plane of the mirror substrate, the second transparent component having a first surface through which the light beam enters into the second transparent component, and a second surface through which the light beam leaves the second transparent component, the second surface being substantially parallel to the outer surface.

38. The optical switch of claim 37 wherein the second surface is mounted to the outer surface.

39. The optical switch of claim 38 wherein the transparent housing has a second outer surface at an angle relative to the plane of the mirror substrate, further comprising:

a reflective substrate mounted over the second outer surface.

40. The optical switch of claim 27 wherein the first optical splitter splits the light beam after entering the output optical fiber.

41. The optical switch of claim 40 wherein the first optical splitter is an optical splitting coupler located in the output optical fiber, further comprising:

a monitoring optical fiber connected to the coupler so that the first propagated portion propagates from the coupler through the output optical fiber and the first monitoring portion propagates through the monitoring optical fiber to the first optical detector.

42. The optical switch of claim 27 wherein the first optical splitter is an input optical splitter that splits the light beam at a location before being reflected by the input pivoting mirror, the first propagated portion being an input propagated portion, the first monitoring portion being an input monitoring portion and the first detector being an input detector, further comprising:

an output optical splitter located in a path of the light beam at a location after being reflected by the input pivoting mirror; and

an output detector, the output optical splitter splitting the input propagated portion into an output propagated portion and an output monitoring portion, the output propagated portion being propagated through the output optical fiber and the output monitoring portion being received by the output detector.

43. The optical switch of claim 1 further comprising:

an output pivoting mirror that is pivotal relative to the mirror substrate, the light beam being reflected by the output pivoting mirror after being reflected, by the input pivoting mirror but before entering the output optical fiber, wherein the first optical splitter splits the light beam after being reflected by the input pivoting mirror but before being reflected by the output pivoting mirror.

44. The optical switch of claim 43 further comprising:

a reflective substrate having a reflective surface that reflects the light beam after being reflected by the input pivoting mirror but before being reflected by the output pivoting mirror, wherein the reflective substrate is the first optical splitter, the first propagated portion being reflected by the reflective substrate and the first monitoring portion propagating through the reflective substrate.

45. The optical switch of claim 44 wherein the detector receives the first monitoring portion when the input pivoting mirror is in a selected orientation and not when the input pivoting mirror is out of the selected orientation.

46. The optical switch of claim 44 further comprising:

a lens between the reflective substrate and the detector.

47. The optical switch of claim 46 wherein the detector receives the first monitoring portion regardless of an orientation of the input pivoting mirror.

9. An optical switch comprising:

an input optical fiber to propagate a light beam;

a mirror substrate;

an input pivoting mirror located in a path of the light beam after leaving the input optical fiber, the input pivoting mirror being pivotally secured to the mirror substrate, pivoting of the input pivoting mirror relative to the mirror substrate altering an angle with which the light beam is reflected therefrom;

an output optical fiber, having an end through which the light beam enters after being reflected by the input pivoting mirror;

a first optical splitter located in a path of the light beam after leaving the input optical fiber;

an output pivoting mirror that is pivotal relative to the mirror substrate, the light beam being reflected by the output pivoting mirror after being reflected by the input pivoting mirror but before entering an output optical fiber; and

a first optical detector, the first optical splitter splitting the light beam into a first propagated portion and a first monitoring portion, the first propagated portion being propagated through the output optical fiber and the first monitoring portion being received by the first optical detector.

10. The optical switch of claim 9 wherein the first optical splitter splits the light beam after a being reflected by the output pivoting mirror.

11. The optical switch of claim 9 further comprising:

a reflective substrate having a reflective surface that reflects the light beam after being reflected by the input pivoting mirror but before being reflected by the output pivoting mirror.

12. The optical switch of claim 11 wherein the output pivoting mirror is pivotally mounted to the mirror substrate and is substantially in a common plane as the input pivoting mirror.

13. The optical switch of claim 12 wherein the first optical splitter is an input optical splitter that splits the light beam at a location before being reflected by the input pivoting mirror, the first propagated portion being an input propagated portion, the first monitoring portion being an input monitoring portion and the first detector being an input detector, further comprising:

an output optical splitter located in a path of the light beam at a location after being reflected by the input pivoting mirror; and

an output detector, the output optical splitter splitting the input propagated portion into an output propagated portion and an output monitoring portion, the output propagated portion being propagated through the output optical fiber and the output monitoring portion being received by the output detector.

14. The optical switch of claim 13 further comprising:

a transmissive substrate, the input optical splitter being a first, partially transmissive input optical splitter mirror, on the transmissive substrate, that propagates the input propagated portion therethrough and reflects the input monitoring portion therefrom, and the output optical splitter is an output optically splitting coupler located in the output fiber;

a monitoring optical fiber being connected to the coupler so that the output propagated portion is propagated through the output optical fiber and the output monitoring portion is propagated through the monitoring optical fiber; and

a second, reflective mirror on the transmissive substrate, that reflects the light beam, after leaving the separator optical fiber, towards the output optical detector.

15. The optical switch of claim 14 wherein the input propagated portion propagates through the transmissive substrate after being reflected by the input pivoting mirror and before entering the output optical fiber.

16. The optical switch of claim 15 wherein the transmissive substrate is a planar substrate being mounted to the housing at an angle other than 90°

with respect to the light beam being propagated therethrough.

17. The optical switch of claim 14 comprising:

a plurality of said input optical fibers, each propagating a respective light beam;

a plurality of said input pivoting mirrors, each reflecting a respective light beam;

a plurality of said output pivoting mirrors, each reflecting a respective light beam;

a plurality of said output optical fibers, each propagating a respective light beam.

18. The optical switch of claim 17 comprising:

one or more of said partially transmissive input optical splitter mirrors splitting each light beam into a respective input propagated portion and a respective input monitoring portion;

a plurality of said input detectors each detecting a respective input monitoring portion;

a plurality of said couplers, each being located in a respective output fiber;

a plurality of said monitoring optical fibers, each connected to a respective coupler to propagate a respective output detector portion;

one or more of said second reflective mirrors reflecting the output monitoring portions; and

a plurality of said output detectors, each receiving a respective output monitoring portion.

19. The optical switch of claim 12 further comprising a transmissive mirror array cover located over the input and output pivoting mirrors, having at least one inclined surface that is inclined with respect to the mirror substrate and through which the light beam propagates.

20. The optical switch of claim 19 wherein the mirror substrate extends in a mirror substrate plane, the light beam propagates at a substrate light beam angle relative to the mirror substrate plane towards the mirror substrate and the inclined surface extends at an angle relative to the mirror substrate plane, the light beam propagating at an inclined surface-light beam angle that is more than the substrate-light beam angle towards the inclined surface.

21. The optical switch of claim 20 wherein the inclined surface-light beam angle is substantially 90°

.

22. The optical switch of claim 21 wherein the light beam leaves the cover at an angle that is substantially 90°

.

48. The optical switch of claim 9 wherein at least one of the pivoting mirrors is the first optical splitter, the respective pivoting mirror being partially transmissive so that the first propagated portion is reflected by the pivoting mirror and the monitoring portion is propagated through the pivoting mirror.

49. The optical switch of claim 48 wherein both the input and output pivoting mirrors are partially transmissive, the first propagated portion being reflected by the input pivoting mirror, the input monitoring portion being propagated by the input pivoting mirror, the first propagated portion being partially reflected by the output pivoting mirror in the form of an output propagated portion and partially propagated in the form of an output monitoring portion.

50. The optical switch of claim 49 wherein the detector is an input detector located behind the input pivoting mirror, further comprising:

an output detector located behind the output pivoting mirror.

51. An optical switch, comprising:

a housing;

an input optical fiber, to propagate a light beam, secured to the housing;

a mirror substrate secured to the housing;

an input pivoting mirror located in a path of the light beam after leaving to input optical fiber, the input pivoting mirror being pivotally secured to the mirror substrate, pivoting of the input pivoting mirror relative to the mirror substrate altering an angle with which the light beam is reflected therefrom;

an output optical fiber, having an end through which the light beam enters after being reflected by the input pivoting mirror;

a first optical splitter located in a path of the light beam after leaving the input optical fiber;

a first optical detector, the first optical splitter splitting the light beam into a first propagated portion and a first monitoring portion, the first propagated portion being propagated through the output optical fiber and the first monitoring portion being received by the first optical detector, wherein the first optical splitter splits the light beam at a location after leaving the input optical fiber; and

an output pivoting mirror that is pivotal relative to the mirror substrate, the light beam being reflected by the output pivoting mirror after being reflected by the input pivoting mirror but before entering the output optical fiber, wherein the first optical splitter splits the light beam after being reflected by the input pivoting mirror but before being reflected by the output pivoting mirror.

52. The optical switch of claim 51 wherein the first optical splitter splits the light beam after being reflected by the input pivoting mirror.

53. The optical switch of claim 52 wherein the first optical splitter is a partially transmissive optical splitter mirror that propagates one, and reflects the other one, of the first propagated portion and the first monitoring portion.

54. The optical switch of claim 51 wherein the first optical splitter is an input optical splitter that splits the light beam at a location before being reflected by the input pivoting mirror, the first propagated portion being an input propagated portion, the first monitoring portion being an input monitoring portion and the first detector being an input detector, further comprising:

an output optical splitter located in a path of the light beam at a location after being reflected by the input pivoting mirror; and

an output detector, the output optical splitter splitting the input propagated portion into an output propagated portion and an output monitoring portion, the output propagated portion being propagated through the output optical fiber and the output monitoring portion being detected by the output detector.

55. An optical switch comprising:

a housing;

a retaining block on the housing;

a plurality of input optical fibers each to propagate a respective light beam, secured to the retaining block;

a mirror substrate secured to the housing;

a plurality of input pivoting mirrors, each located in the path of a respective light beam leaving a respective input optical fiber, and each being pivotally secured to the mirror substrate, pivoting of the respective input pivoting mirror relative to the mirror substrate altering an angle with which the light beam is reflected therefrom;

a reflecting substrate mounted to the housing and positioned to reflect the light beams after being reflected by the input pivoting mirrors;

a plurality of output pivoting mirrors, each located in a path of a respective light beam after being reflected by the reflective substrate, and each being pivotally secured to the mirror substrate, pivoting of a respective output pivoting mirror relative to the mirror substrate altering an angle with which the light beam is reflected therefrom;

a plurality of output optical fibers secured to the retained block, a respective light beam coupling into a selected output optical fiber after being reflected by a respective output pivoting mirror;

a first optical splitter located in a path of each light beam after leaving the input optical fiber but before being reflected by the input pivoting mirrors;

a first optical detector, the first optical splitter splitting the light beam into a first propagated portion and a first monitoring portion, the first propagated portion being propagated through the output optical fiber and the first monitoring portion being received by the first optical detector.

56. A method of switching light, comprising:

propagating a light beam from an input optical fiber;

reflecting the light beam from an input pivoting mirror after leaving the input optical fiber;

pivoting the input pivoting mirror;

propagating the light beam through an output optical fiber, pivoting of the input pivoting mirror ensuring coupling of the light beam with the output optical fiber;

splitting the light beam into a first propagated portion and a first monitoring portion, the first propagated portion being propagated through the output optical fiber;

splitting the light beam after leaving the input optical fiber but before being reflected from the pivoting mirror; and

receiving the first monitoring portion.