Symmetrical optical matrix crossconnect apparatus and method therefor

• US 6,144,781 A
• Filed: 12/31/1997
• Issued: 11/07/2000
• Est. Priority Date: 12/31/1997
• Status: Expired due to Term

• Current Assignee: AT&T Corporation (AT&T, Inc.)
• Original Assignee: AT&T Corporation (AT&T, Inc.)
• Inventors: Lin, Lih-Yuan, Simmons, Jane Marie, Goldstein, Evan Lee
• Primary Examiner(s): Bovernick, Rodney
• Assistant Examiner(s): Wise, Robert E.
• Application Number:
  US09/002,240
• Time in Patent Office: 1,042 Days
• Field of Search: 385/18, 385/16, 385/17, 385/19, 385/20, 385/47
• US Class Current: 385/18
• CPC Class Codes: G02B 6/3512 the optical element being reflective, e.g. mirror
• CPC Class Codes: G02B 6/3546 NxM switch, i.e. a regular array of switches elements of matrix type constellation
• CPC Class Codes: G02B 6/356 in an optical cross-connect device, e.g. routing and switching aspects of interconnecting different paths propagating different wavelengths to (re)configure the various input and output links switching polarized beams G02B6/3594; power equalizers G02B6/356 and G02B6/3594; path selecting means H04Q11/0001
• CPC Class Codes: H04Q 11/0005 Switch and router aspects
• CPC Class Codes: H04Q 2011/0026 using free space propagation (e.g. lenses, mirrors)
• CPC Class Codes: H04Q 2011/0058 Crossbar; Matrix

Abstract

A symmetrical optical matrix crossconnect apparatus includes a plurality of optical switch devices with each comprising a first pair of fiber optic ports, a second pair of fiber optic ports and a reflective element. The first pair of fiber optic ports are disposed apart from one another and aligned coextensively along a first optical path. One of the first pair of fiber optic ports emits a first light beam that travels along the first optical path in free space while the remaining one of the first pair of fiber optic ports receives the first light beam. The second pair of fiber optic ports are disposed apart from one another and aligned coextensively along a second optical path. A first one of the second pair of fiber optic ports emits a second light beam that travels along the second optical path in free space while a remaining one of the second pair of fiber optic ports receives the second light beam. The first optical path and the second optical path crisscross each other at an intersection. The reflective element has a first and an opposite second reflective surface and moves between a non-reflective state and a reflective state. In the non-reflective state, the reflective element is disposed away from the first and second optical paths. In the reflective state, the reflective element is interposed into the first and second optical paths at the intersection to reflect the first light beam to a light receiving one of the second pair of fiber optic ports while reflecting the second light beam to the light receiving one of the first pair of fiber optic ports.

Claims

1. A symmetrical optical matrix crossconnect apparatus, comprising:

a first input and a second input different from the first input;

a first output and a second output different from the first output;

a first light beam traveling from the first input to the first output;

a second light beam traveling from the second input to the second output;

the first and second light beams crisscrossing each other at an intersection, and

a reflecting element disposed at the intersection of the first and second light beams, the reflecting element reflecting the first and the second light beams to redirect the first light beam to the second output and the second light beam to the first output.

2. The symmetrical otical matrix crossconnect apparatus of claim 1, further comprising:

a first pair of fiber optic ports disposed apart from one another and aligned coextensively along a first optical path, respective ones of the first pair of fiber optic ports operative for emitting and receiving a first light beam traveling along the first optical path in free space;

a second pair of fiber optic ports disposed apart from one another and aligned coextensively along a second optical path, respective ones of the second pair of fiber optic ports operative for emitting and receiving a second light beam traveling along the second optical path in free space, the first optical path and the second optical path crisscrossing each other at an intersection; and

a reflective element for reflecting the first light beam emitted by a light emitting first one of the first pair of fiber optic ports to a light receiving second one of the second pair of fiber optic ports while reflecting the second light beam emitted by a light emitting second one of the second pair of fiber optic ports to a light receiving first one of the first pair of fiber optic ports by moving the reflective element between a non-reflective state and a reflective state, the reflective element being disposed away from the first and second optical paths in the non-reflective state and being interposed into the first and second optical paths at the intersection in the reflective state.

3. The symmetrical optical matrix crossconnect apparatus according to claim 2, wherein the reflective element has a first reflective surface and an opposite second reflective surface.

4. The symmetrical optical matrix crossconnect apparatus according to claim 2, further comprising a base member and an actuator, the base member having the reflective element pivotally connected thereto, the actuator connected to the base member and the reflective element and operative to cause the reflective element to move to and between the reflective state and the non-reflective state.

5. The symmetrical optical matrix crossconnect apparatus according to claim 4, wherein the actuator includes a hinge assembly and a translation plate, the hinge assembly having at least one connecting rod with a first end of the connecting rod pivotally connected to the reflective element and an opposite second end pivotally connected to the translation plate, the translation plate slidably connected to the base member and movable between a first position wherein the reflective element is in the reflective state and a second position wherein the reflective element is in the non-reflective state.

6. The symmetrical optical matrix crossconnect apparatus according to claim 2, wherein the reflective element defines a plane extending in a longitudinal direction and a lateral direction being orthogonal to the longitudinal direction, the optical paths being oriented perpendicularly relative to the longitudinal direction and obliquely relative to the lateral direction when the reflective element is in the reflective state.

7. The symmetrical opticl matrix crossconect apparatus of claim 1, further comprising:

M pairs of fiber optic ports wherein M is an integer greater than 1, each pair of fiber optic ports including a light emitting port for emitting a beam of light and a light receiving port for receiving another beam of light, the light emitting port and light receiving port of each pair of fiber optic ports defining one optical path, the plurality of optical paths crisscrossing one another to define a plurality of light beam intersections with each light beam intersection formed by only two crisscrossing optical path segments;

one or more reflective elements, each reflective element having a first reflective surface and an opposite second reflective surface, being associated with a respective one of each light beam intersection and operative to move between a non-reflective state whereby respective ones of the reflective elements are disposed away from the associated light path intersections thereby permitting two intersecting light beams to travel along respective optical paths from a first light emitting port to a corresponding first light receiving port and from a second light emitting port to a corresponding second light receiving port, and a reflective state whereby one reflective element is interposed into the light beam intersection where the two intersecting light beams crisscross thereby redirecting one light beam from the first light emitting port to the second light receiving port and a remaining light beam from the second light emitting port to the first light receiving port; and

at least one actuator, each actuator being associated with at least one reflective element, the actuator being operative to move each associated reflective element between the reflective states and the non-reflective states.

8. The symmetrical optical matrix crossconnect apparatus according to claim 7, wherein M is selected from a group of integers consisting of 3, 4 and 5.

9. The symmetrical optical matrix crossconnect apparatus according to claim 8, wherein when at least one reflective element is in the reflective state, remaining ones of the reflective elements disposed along the crisscrossing optical paths in which the reflective element is interposed are in the non-reflective state.

10. The symmetrical optical matrix crossconnect apparatus according to claim 8, comprising one actuator that moves all the reflective elements.

11. The symmetrical optical matrix crossconnect apparatus of claim 1, wherein the reflective element has a first reflective surface disposed on the front side of the reflective element and a second reflective surface disposed on the rear side of the reflective element.

12. A symmetrical optical matrix crossconnect apparatus for redirecting a selected two of at least three light beams traveling in free space along respective optical paths, the at least three light beams being oriented so that the at least three light beams crisscross to form a plurality of light beam intersections with only two of the light beams crisscrossing at one intersection at a time;

the symmetrical optical matrix crossconnect comprising;

a plurality of reflective elements for redirecting at least a first one of the light beams from a first reflective surface of a reflective element while redirecting at least a second one of the light beams from a second reflective surface of the reflective element.

13. The symmetrical optical matrix crossconnect apparatus according to claim 12, wherein when one reflective element is in the reflective state, remaining ones of the reflective elements associated with the light path intersections disposed along the crisscrossing optical paths in which the reflective element is interposed are in the non-reflective state.

14. The symmetrical optical matrix crossconnect apparatus of claim 12, wherein each reflective element having a first reflective surface and an opposite second reflective surface and associated with each light path intersection, each reflective element movable between a non-reflective state whereby respective ones of the reflective elements are disposed away from the associated light path intersections thereby permitting the light beams to travel along the respective optical paths and a reflective state whereby at least one reflective element is interposed into the associated light path intersection thereby redirecting a first one of the light beams from the first reflective surface while redirecting a second one of the light beams from the second reflective surface.

15. A method for symmetrically crossconnecting a first light beam traveling in free space from a first input to a first output and a second light beam traveling in free space from a second input different from a first input to a second output different from the first output the first and second light beams crisscrossing each other at an intersection, the method comprising the steps of:

disposing a reflective element at the intersection of the first and second light beams;

directing the first and second light beams traveling from the respective first and second inputs to the reflecting element; and

reflecting the first beams to redirect the first light beam to the second output and the second light beam to the first output.

16. The method according to claim 15, wherein the reflective element has a first reflective surface and an opposite second reflective surface, the first beam reflecting on the first reflective surface in the non-reflective state and the second beam reflecting on the second reflective surface in the reflective state.

17. The method of claim 15, wherein the first light beam is reflected by a front side of the reflective element to redirect the first light beam to the second output and the second light beam is reflected by a rear side of the reflective element to redirect the second light beam to the first output.

18. A method for symmetrically crossconnecting a symmetrical optical matrix for redirecting a selected two of at least three light beams traveling in free space along respective optical paths, the at least three light beams being oriented so that the at least three light beams crisscross to form a plurality of light beam intersections with only two of the light beams crisscrossing at one intersection at a time, the method comprising:

redirecting at least a first one of the light beams from a first reflective surface of a reflective element while redirecting at least a second one of the light beams from a second reflective surface of the reflective element.

19. The method according to claim 18, wherein when one reflective element is in the reflective state, remaining ones of the reflective elements associated with the light path intersections disposed along the crisscrossing optical paths in which the reflective element is interposed are in the non-reflective state.