Optical switch for reciprocal traffic

• US 6,850,662 B1
• Filed: 10/07/2003
• Issued: 02/01/2005
• Est. Priority Date: 07/31/2000
• Status: Expired due to Term

• Current Assignee: Tellabs Operations Incorporated (Infinera Corp.)
• Original Assignee: Tellabs Operations Incorporated (Infinera Corp.)
• Inventors: Lin, Philip J., Holmstrom, Roger P., Mills, James D.
• Primary Examiner(s): Palmer, Phan T. H.
• Application Number:
  US10/680,443
• Time in Patent Office: 483 Days
• Field of Search: 385 16- 18, 385 20- 21, 385/24, 398/108, 398/110, 398/119, 398/130
• US Class Current: 385/18
• 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 6/3542 Non-blocking switch, e.g. with multiple potential paths between multiple inputs and outputs, the establishment of one switching path not preventing the establishment of further switching paths
• CPC Class Codes: G02B 6/3546 NxM switch, i.e. a regular array of switches elements of matrix type constellation
• CPC Class Codes: H04Q 11/0005 Switch and router aspects
• CPC Class Codes: H04Q 2011/0024 using space switching
• CPC Class Codes: H04Q 2011/0026 using free space propagation (e.g. lenses, mirrors)
• CPC Class Codes: H04Q 2011/0039 Electrical control
• CPC Class Codes: H04Q 2011/0056 Clos
• CPC Class Codes: H04Q 2011/0058 Crossbar; Matrix

Abstract

A reduced component optical switch module includes a plurality of ports wherein each port includes an optical input and an optical output. A plurality of switchable deflectors in combination with a plurality of non-switchable deflectors can be used to establish transmission paths between pairs of ports to support traffic reciprocity. In one embodiment, the ports and switchable elements are configured so as to provide substantially constantly transmission paths within the respective module. In another embodiment, additional deflector elements can be provided to implement loop-back functionality at one or more of the ports.

Claims

1. A multi-stage modular optical switch comprising:

a first group (L, 2L-1) switching modules, the first group having M members and configured to support non-blocking reciprocal traffic at LXM ports;

a second group of M-way reciprocal switching modules, the second group having 2L-1 members with each configured to support non-blocking reciprocal traffic at M ports with each member of the second group having less than [N*(N−

1)/2] switchable deflectors.

2. A switch as in claim 1 which includes M×

(2L-1) interconnections between the groups.

3. A switch as in claim 2 where each member of the second group incorporates as switchable deflecting elements one of switchable reflectors, optical bubbles or holographic gratings.

4. A switch as in claim 3 where the deflecting elements are arranged on transmission paths having a substantial common predetermined length.

5. A switch as in claim 2 where each member of the second group incorporates a plurality of transmission paths which have substantially a common length.

6. A switch as in claim 2 where at least some members of the second group include a loop-back element.

7. A switch as in claim 1 which includes signal interconnections between members of the first group and members of the second group.

8. A switch as in claim 7 where each of 2L-1 ports of each member of the first group is coupled to a port of a different one of the 2L-1 members of the second group.

9. A switch as in claim 8 which includes M×

(2L-1) interconnections between the groups.

10. A modular switch for non-blocking reciprocal traffic comprising:

a first plurality of substantially identical bidirectional switching modules, the ports of each member of the plurality support reciprocal traffic;

a second plurality of substantially identical reciprocal traffic switching modules, each member of the second plurality has M inputs and on the order of [M*(M−

1)2] switchable path selecting elements and each member of the second plurality is coupled to the members of the first plurality to support non-blocking reciprocal traffic relative to the ports of the first plurality.

11. A modular switch as in claim 10 where the members of the second plurality exhibit substantially a common path length.

12. A modular switch for non-blocking reciprocal traffic comprising:

a plurality of substantially identical bi-directional switching modules, each of the modules has a plurality of bi-directional ports;

a plurality of substantially identical reciprocal traffic switching modules, each member of the plurality of reciprocal traffic modules has a selected number of inputs and has switchable path selecting elements on the order of one half the selected number multiplied by itself;

each member of the plurality of reciprocal traffic modules is coupled to the members of the plurality of bi-directional switching modules to support non-blocking reciprocal traffic relative to the ports.

13. A method of implementing signal switching comprising:

coupling any one of L input signals in M groups, to any one of (2L-1) outputs in M groups;

transferring each of the (2L-1) outputs to one of the M inputs in (2L-1) groups;

switching each of the M inputs, as an intermediate output, to any one of the other M-1 inputs to implement non-blocking reciprocal traffic among at least M bidirectional paths;

coupling each of the intermediate outputs to a different group of (2L-1) outputs; and

providing the coupled intermediate outputs to at least some of the L input signals in M groups.

14. A method as in claim 13 including providing bi-directional coupling of L input signals with (2L-1) outputs for at least some of the M groups.

15. A method as in claim 14 including switching signals among the M groups with substantially a common path length.

16. A method as in claim 13 where at least M bi-directional paths have a substantially common length.

17. A method as in claim 13 including altering at least M bi-directional paths at [M*(M−

1)/2]−

1 sites.

18. A method of switching communications signals comprising:

injecting up to N communications signals into a region;

deflecting selected pairs of injected signals at up to (N*(N−

1)/2)−

1 locations so that each of the members of each pair of injected signals becomes an output associated with the other injected signal of the respective pair.

19. A method as in claim 18 which includes looping selected of the injected signals back on themselves to form a pair of substantially identical signals, one being the injected signal, the other being an output signal.

20. A method as in claim 18 which includes deflecting first and second pairs of signals so that the signals of each pair traverse a common path length.

21. A method as in claim 18 which includes arranging first and second pairs of signals so that the signals of each pair traverse a common path length.

22. A method of switching communications signals comprising:

injecting up to a selected number of communications signals into a region;

deflecting selected pairs of injected signals at up to a selected number of locations so that each of the members of each pair of injected signals becomes an output associated with the other injected signal of the respective pair.

23. A method as in claim 22 which includes looping selected of the injected signals back on themselves to form a pair of substantially identical signals, one being the injected signal, the other being an output signal.

24. A method as in claim 22 which includes deflecting first and second pairs of signals so that the signals of each pair traverse a common path length.

25. A method as in claim 22 which includes arranging first and second pairs of signals so that the signals of each pair traverse a common path length.

26. A method of implementing signal switching comprising:

selecting a number of inputs;

dividing the inputs into a first number of groups;

coupling any one of the inputs in any one of the groups to any one of a selected number of outputs, on the order of twice the number of inputs in any one of the groups;

selecting a second number of inputs;

selecting a second number of groups, the second number is on the order of twice the number of inputs in any one of the first groups;

coupling each of the outputs to one of the second inputs in the second groups to implement non-blocking reciprocal traffic among at least as many paths as the number of inputs.

27. A method as in claim 26 where the paths are bidirectional and have a common length.

28. A method as in claim 26 where the second number of inputs corresponds to the first number of groups.