Method and apparatus for optical to electrical to optical conversion in an optical cross-connect switch

• US 6,650,803 B1
• Filed: 11/01/2000
• Issued: 11/18/2003
• Est. Priority Date: 11/02/1999
• Status: Expired due to Term

• Current Assignee: RPX Clearinghouse LLC (RPX Corporation)
• Original Assignee: Xros, Inc. (Nortel Networks Corporation)
• Inventors: Ward, Robert R., Ramaswami, Rajiv
• Primary Examiner(s): Healy, Brian
• Application Number:
  US09/704,439
• Time in Patent Office: 1,112 Days
• Field of Search: 385/16, 385/17, 385/18, 359/117, 359/123, 359/128, 359/139, 359/115, 359/124
• US Class Current: 385/17
• CPC Class Codes: G02B 6/43 Arrangements comprising a plurality of opto-electronic elements and associated optical interconnections
• CPC Class Codes: H04J 14/0293 Optical channel protection
• CPC Class Codes: H04J 14/0297 Optical equipment protection
• CPC Class Codes: H04Q 11/0005 Switch and router aspects
• CPC Class Codes: H04Q 11/0062 Network aspects
• CPC Class Codes: H04Q 2011/0009 using wavelength filters
• CPC Class Codes: H04Q 2011/0015 using splitting combining
• 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 2011/0035 using miscellaneous components, e.g. circulator, polarisation, acousto/thermo optical
• CPC Class Codes: H04Q 2011/0041 Optical control
• CPC Class Codes: H04Q 2011/0043 Fault tolerance
• CPC Class Codes: H04Q 2011/005 Arbitration and scheduling
• CPC Class Codes: H04Q 2011/0058 Crossbar; Matrix
• CPC Class Codes: H04Q 2011/0073 Provisions for forwarding or routing, e.g. lookup tables
• CPC Class Codes: H04Q 2011/0081 Fault tolerance; Redundancy; Recovery; Reconfigurability
• CPC Class Codes: H04Q 2011/0083 Testing; Monitoring
• CPC Class Codes: H04Q 2011/0088 Signalling aspects

Abstract

Methods, apparatus and systems for regenerating, monitoring and bridging optical signals through an optical cross-connect switch to provide increased reliability. A self testing method, apparatus and system for an optical cross-connect switch. An optical-to-electrical-to-optical converter (O/E/O) is provided in an optical cross-connect switch to provide optical-electrical-optical conversion. I/O port cards having an optical-to-electrical-to-optical converter are referred to as smart port cards while I/O port cards without an optical-to-electrical-to-optical converter are referred to as passive port cards. Test port/monitor cards are also provided for testing optical cross-connect switches. Methods, apparatus and systems for performing bridging, test access, and supporting redundant optical switch fabrics are also disclosed.

Claims

1. An optical cross-connect switch comprising:

an optical switch fabric of optical switches to switch optical signals from one optical network connection to another optical network connection; and

,

an optical-electrical-optical converter (O/E/O) coupled between the optical switch fabric and the one optical network connection, the optical-electrical-optical converter to convert an optical signal into an electrical signal and the electrical signal into a regenerated optical signal.

2. The optical cross-connect switch of claim 1 wherein,

the optical-electrical-optical converter (O/E/O) is included in one or more port cards to couple to the one optical network connection.

3. The optical cross-connect switch of claim 1 wherein,

the electrical signal generated by the optical-electrical-optical converter to regenerate optical signals of a channel connection provided by the optical cross-connect switch.

4. The optical cross-connect switch of claim 1 wherein,

the electrical signal generated by the optical-electrical-optical converter to monitor optical signals of a channel connection provided by the optical cross-connect switch.

5. An optical cross-connect switch comprising:

an optical switch fabric of optical switches to switch optical signals from one optical network connection to another optical network connection;

one or more port cards to couple to the one optical network connection, at least one of the one or more port cards including

an optical-electrical-optical converter (O/E/O) coupled between the optical switch fabric and the one optical network connection, the optical-electrical-optical converter to convert an optical signal into an electrical signal and the electrical signal into a regenerated optical signal; and

,

wherein the at least one of the one or more port cards including the optical-electrical-optical converter is a smart port card.

6. The optical cross-connect switch of claim 5 wherein,

at least another one of the one or more port cards does not include an optical-electrical-optical converter and is coupled between the optical switch fabric and the one optical network connection or the another optical network connection, the at least another one of the one or more port cards not including an optical-electrical-optical converter is a passive port card.

7. The optical cross-connect switch of claim 6 wherein,

one or more smart port cards are tiered with one or more passive port cards in the optical cross-connect switch and wherein

the one or more smart port cards couple to the one or more passive port cards and the one optical network connection and

the one or more passive port cards tiered with the one or more smart port cards couple to the optical switch fabric.

8. The optical cross-connect switch of claim 6 wherein,

the smart port cards provide the regeneration of optical signals and the passive port cards provide the connection to the optical switch fabric.

9. The optical cross-connect switch of claim 8 wherein,

the smart port cards additionally monitor the optical signals.

10. An optical cross-connect switch comprising:

an optical switch fabric of optical switches to switch optical signals from one optical network connection to another optical network connection; and

one or more port cards to couple to the one optical network connection, at least one of the one or more port cards including

an optical-electrical-optical converter (O/E/O) coupled between the optical switch fabric and the one optical network connection, the optical-electrical-optical converter to convert an optical signal into an electrical signal and the electrical signal into a regenerated optical signal, wherein the optical-electrical-optical converter is in an input path of the at least one of the one or more port cards including the optical-electrical-optical converter.

11. An optical cross-connect switch comprising:

an optical switch fabric of optical switches to switch optical signals from one optical network connection to another optical network connection; and

one or more port cards to couple to the one optical network connection, at least one of the one or more port cards including

an optical-electrical-optical converter (O/E/O) coupled between the optical switch fabric and the one optical network connection, the optical-electrical-optical converter to convert an optical signal into an electrical signal and the electrical signal into a regenerated optical signal, wherein the optical-electrical-optical converter is in an output path of the at least one of the one or more port cards including the optical-electrical-optical converter.

12. An optical cross-connect switch comprising:

an optical switch fabric of optical switches to switch optical signals from one optical network connection to another optical network connection;

one or more port cards to couple to the one optical network connection, at least one of the one or more port cards including

an optical-electrical-optical converter (O/E/O) coupled between the optical switch fabric and the one optical network connection, the optical-electrical-optical converter to convert an optical signal into an electrical signal and the electrical signal into a regenerated optical signal; and

,

wherein the at least one of the one or more port cards including the optical-electrical-optical converter having the optical-electrical-optical converter on an input side of the optical cross-connect switch.

13. An optical cross-connect switch comprising:

an optical switch fabric of optical switches to switch optical signals from one optical network connection to another optical network connection;

one or more port cards to couple to the one optical network connection, at least one of the one or more port cards including

an optical-electrical-optical converter (O/E/O) coupled between the optical switch fabric and the one optical network connection, the optical-electrical-optical converter to convert an optical signal into an electrical signal and the electrical signal into a regenerated optical signal; and

,

wherein the at least one of the one or more port cards including the optical-electrical-optical converter having the optical-electrical-optical converter on an output side of the optical cross-connect switch.

14. An optical cross-connect switch comprising:

an optical switch fabric of optical switches to switch optical signals from one optical network connection to another optical network connection;

one or more port cards to couple to the one optical network connection, at least one of the one or more port cards including

an optical-electrical-optical converter (O/E/O) coupled between the optical switch fabric and the one optical network connection, the optical-electrical-optical converter to convert an-optical signal into an electrical signal and the electrical signal into a regenerated optical signal, wherein the optical-electrical-optical converter includes

an optical-electrical converter (O/E) having an electrical output, and

an electrical-optical converter (E/O) having an electrical input coupled in series to the electrical output of the optical-electrical converter (O/E).

15. The optical cross-connect switch of claim 14 wherein,

the optical-electrical converter (O/E) is an optical receiver to receive an optical signal and convert it into an electrical signal.

16. The optical cross-connect switch of claim 15 wherein,

the optical receiver is a photodetector.

17. The optical cross-connect switch of claim 15 wherein,

the optical receiver to receive optical signals having a range of wavelengths.

18. The optical cross-connect switch of claim 14 wherein,

the electrical-optical converter (E/O) is an optical transmitter to receive an electrical signal and convert it into an optical signal.

19. The optical cross-connect switch of claim 18 wherein,

the electrical-optical converter (E/O) is a semiconductor laser.

20. The optical cross-connect switch of claim 14 wherein,

the electrical-optical converter (E/O) is a tunable optical transmitter to receive an electrical signal and convert it into an optical signal having a desired wavelength.

21. The optical cross-connect switch of claim 20 wherein,

the electrical-optical converter (E/O) is a multimode semiconductor laser that is tunable to the desired wavelength.

22. A data communication network comprising:

an optical cross-connect switch including

an optical switch fabric of optical switches to switch optical signals from one optical network connection to another optical network connection, and

an optical-electrical-optical converter coupled between the optical switch fabric and the one optical network connection or the another optical network connection, the optical-electrical-optical converter to convert an incoming optical signal into an electrical signal and the electrical signal into an outgoing optical signal, the incoming optical signal and the outgoing optical signal being substantially similar; and

attached network equipment coupled to the optical cross-connect switch, the attached network equipment coupled to one or more port cards to bi-directionally transport optical signals there-between.

23. The data communications network of claim 22 wherein

the optical-electrical-optical converter is included in another one or more port cards to couple to the one optical network connection and the another optical network connection.

24. The data communications network of claim 22 wherein

the optical-electrical-optical converter monitors an incoming optical signal into the optical cross-connect switch.

25. The data communications network of claim 22 wherein

the optical-electrical-optical converter monitors an outgoing optical signal from the optical cross-connect switch.

26. The data communications network of claim 22 wherein

the optical-electrical-optical converter to regenerate a switched optical input signal from the optical switch fabric into an optical output signal.

27. The data communications network of claim 22 wherein

the optical-electrical-optical converter to regenerate an optical input signal input into the optical cross-connect switch into a routable optical signal for routing through the optical switch fabric.

29. The optical cross-connect switch of claim 24 wherein,

the optical-electrical-optical converter is included in one or more port cards to couple to the one optical network connection.

30. The optical cross-connect switch of claim 24 wherein,

the optical switches in the first optical switch fabric and the second optical switch fabric are micro-machined mirrors to direct the optical signals from the one optical network connection to the another optical network connection.

31. The optical cross-connect switch of claim 24 wherein,

the electrical signal generated by the optical-electrical-optical converter is for regeneration of optical signals over a channel connection provided by the optical cross-connect switch.

28. An optical cross-connect switch comprising:

a first optical switch fabric of optical switches to switch optical signals from one optical network connection to another optical network connection;

a second optical switch fabric of optical switches to switch optical signals from the one optical network connection to the another optical network connection; and

,

an optical-electrical-optical converter (O/E/O) coupled between the first and second optical switch fabrics and the one optical network connection, the optical-electrical-optical converter to convert an incoming optical signal into an electrical signal and the electrical signal into an outgoing optical signal, the incoming optical signal and the outgoing optical signal being substantially similar.

32. An optical cross-connect switch comprising:

a first optical switch fabric of optical switches to switch optical signals from one optical network connection to another optical network connection;

a second optical switch fabric of optical switches to switch optical signals from the one optical network connection to the another optical network connection;

one or more port cards to couple to the one optical network connection, at least one of the one or more port cards including

an optical-electrical-optical converter (O/E/O) coupled between the first and second optical switch fabrics and the one optical network connection, the optical-electrical-optical converter to convert an incoming optical signal into an electrical signal and the electrical signal into an outgoing optical signal, the incoming optical signal and the outgoing optical signal being substantially similar; and

,

wherein the at least one of the one or more port cards including the optical-electrical-optical converter is a smart port card.

33. The optical cross-connect switch of claim 32 wherein,

at least another one of the one or more port cards is a test monitoring port card, the test monitoring port card including an optical switch and an optical-electrical converter, the optical switch to receive a first optical signal and a second optical signal respectively from the first and second optical switch fabrics, the optical switch to select between the first and second optical signals respectively for testing as the test optical signal, the optical switch coupled to the optical-electrical converter to convert the selected test optical signal into a test electrical signal for monitoring by the optical cross-connect switch.

34. The optical cross-connect switch of claim 32 wherein,

at least another one of the one or more port cards is an active test port card, the active test port card including an optical switch, an optical-electrical converter and an electrical-optical converter, the electrical-optical converter to receive and convert an electrical testing signal into an optical testing signal and couple it into the first or second optical switch fabric to test the first or second optical switch fabric, the optical switch to receive a first optical signal or a second optical signal respectively from the first or second optical switch fabrics responsive to the optical testing signal, the optical switch to select between the first or second optical signals responsive to the coupling of the optical testing signal into the first or second optical switch fabric respectively as the resultant test optical signal, the optical switch coupled to the optical-electrical converter to convert the resultant test optical signal into a resultant test electrical signal for monitoring by the optical cross-connect switch.

35. An optical cross-connect switch comprising:

a first optical switch fabric of optical switches to switch optical signals from one optical network connection to another optical network connection;

a second optical switch fabric of optical switches to switch optical signals from the one optical network connection to the another optical network connection; and

,

one or more port cards to couple to the one optical network connection, at least one of the one or more port cards including

an optical-electrical-optical converter (O/E/O) coupled between the first and second optical switch fabrics and the one optical network connection, the optical-electrical-optical converter to convert an incoming optical signal into an electrical signal and the electrical signal into an outgoing optical signal, the incoming optical signal and the outgoing optical signal being substantially similar, wherein the optical-electrical-optical converter is in an input path of the at least one of the one or more port cards including the optical-electrical-optical converter.

36. An optical cross-connect switch comprising:

a first optical switch fabric of optical switches to switch optical signals from one optical network connection to another optical network connection;

a second optical switch fabric of optical switches to switch optical signals from the one optical network connection to the another optical network connection; and

,

one or more port cards to couple to the one optical network connection, at least one of the one or more port cards including

an optical-electrical-optical converter (O/E/O) coupled between the first and second optical switch fabrics and the one optical network connection, the optical-electrical-optical converter to convert an incoming optical signal into an electrical signal and the electrical signal into an outgoing optical signal, the incoming optical signal and the outgoing optical signal being substantially similar, wherein the optical-electrical-optical converter is in an output path of the at least one of the one or more port cards including the optical-electrical-optical converter.