Wavelength-division multiplexed M×N×M cross-connect switch using active microring resonators

• US 6,195,187 B1
• Filed: 07/07/1998
• Issued: 02/27/2001
• Est. Priority Date: 07/07/1998
• Status: Expired due to Fees

• Current Assignee: Air Force Government of The United States of America As Represented By The Secretary, United States Air Force (Government of the United States of America)
• Original Assignee: United States Of America As Represented By The Secretary Of The Air Force
• Inventors: Little, Brent E., Soref, Richard A.
• Primary Examiner(s): Chan, Jason
• Assistant Examiner(s): Nguyen, Chau M.
• Application Number:
  US09/111,004
• Time in Patent Office: 966 Days
• Field of Search: 359/117, 359/128, 359/139, 385/15, 385/14, 385/16, 385/17, 385/50
• US Class Current: 398/9
• CPC Class Codes: G02B 6/12007 forming wavelength selective elements, e.g. multiplexer, demultiplexer
• CPC Class Codes: G02B 6/29343 Cascade of loop resonators
• CPC Class Codes: G02B 6/2938 for multiplexing or demultiplexing, i.e. combining or separating wavelengths, e.g. 1xN, NxM
• CPC Class Codes: G02B 6/29395 configurable, e.g. tunable or reconfigurable switching G02B6/35
• CPC Class Codes: G02F 1/3133 the optical waveguides being made of semiconducting materials
• CPC Class Codes: G02F 2203/15 involving resonance effects, e.g. resonantly enhanced interaction
• CPC Class Codes: H04Q 11/0005 Switch and router aspects
• CPC Class Codes: H04Q 2011/0016 using wavelength multiplexing or demultiplexing
• CPC Class Codes: H04Q 2011/0035 using miscellaneous components, e.g. circulator, polarisation, acousto/thermo optical
• CPC Class Codes: H04Q 2011/0049 Crosstalk reduction; Noise; Power budget
• 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

Abstract

Large-scale switching array architectures for multiwavelength routing employ absorption-switched micro-ring resonator 2×2 switches at all optical cross-points of each of a plurality of series-connected waveguide crossbar matrix switches. The architecture eliminates detrimental waveguide crossovers. Two or four coupled micro-rings made from layered III-V or II-VI hetrostructure material can aid in maintaining cross-talk at very low levels while employing simple switch addressing methods.

Claims

1. A wavelength-division-multiplexed routing network comprising:

(a) a plurality of N cascaded optical matrix switches connected together in optical series, where N is an integer, each matrix switch including a number of light waveguides and an array of active micro-sized lightwave micro-resonator cross-point light-switching elements associated with cross-points between non-intersecting light waveguide portions, and wherein said light-switching elements of each matrix switch are responsive to a particular wavelength of light λ

_i, where i=1 . . . N, assigned to a particular matrix of the N-wavelength routing network and are unresponsive to other wavelengths assigned to other matrices of the network; and

(b) switching element control means for causing selected light-switching elements to assume a cross state for switching resonant light across associated cross-points, or a bar state for forwarding light without traversing cross-points.

2. The network of claim 1 wherein said cross-point light-switching elements comprise two-by-two cross-point switches.

3. The network of claim 2 wherein each cross-point switching element has an even number of coupled active lightwave micro-resonators and can assume an electrical ON state or an electrical OFF state under the control of said switching element control means.

4. The network of claim 1 wherein each matrix has M input and M output light waveguides, where M is an integer of four or more, and M² cross-point switches, and only M cross-point switches assume the electrical ON state at any one time.

5. The network of claim 2 wherein each matrix has M input and M output light waveguides, where M is an integer of four or more, and M² cross-point switches, and only M cross-point switches assume the electrical ON state at any one time.

6. The network of claim 3 wherein each matrix has M input and M output light waveguides, where M is an integer of four or more, and M² cross-point switches, and only about M cross-point switches assume the electrical ON state at any one time.

7. The network of claim 1 wherein each matrix has a group of output ports and preserves the spatial arrangement of incoming N-1 non-resonant signals at said output ports.

8. The network of claim 2 wherein each matrix has a group of output ports and preserves the spatial arrangement of incoming N-1 non-resonant signals at said output ports.

9. The network of claim 3 wherein each matrix has a group of output ports and preserves the spatial arrangement of incoming N-1 non-resonant signals at said output ports.

10. The network of claim 1 wherein said cross-point light-switching elements comprise semiconductor bulk-heterostructure or multiple-quantum-well electroabsorbtive resonators that have low optical absorption in the field-OFF state and high optical absorption in the field-ON state.

11. The network of claim 2 wherein said cross-point light-switching elements comprise semiconductor bulk-heterostructure or multiple-quantum-well electroabsorbtive resonators that have low optical absorption in the field-OFF state and high optical absorption in the field-ON state.

12. The network of claim 3 wherein said cross-point light-switching elements comprise semiconductor bulk-heterostructure or multiple-quantum-well electroabsorbtive resonators that have low optical absorption in the field-OFF state and high optical absorption in the field-ON state.

26. The network of claim 1 wherein each lightwave micro-resonator includes a p-i-n microdisk diode.

43. The network of claim 1 wherein said lightwave micro-resonators comprise micro-rings.

13. A wavelength-division-multiplexed routing network comprising:

(a) a plurality of cascaded optical matrix switches connected together in optical series, each matrix switch including a number of light waveguides and an array of lightwave micro-resonator cross-point light-switching elements associated with cross-points between non-intersecting light waveguide portions, and wherein said light-switching elements of each matrix switch are responsive to a particular wavelength of light assigned to a particular matrix of the routing network and are unresponsive to other wavelengths assigned to other matrices of the routing network; and

(b) switching element control means for causing selected light-switching elements to assume a cross state for switching resonant light across associated cross-points, or a bar state for forwarding light without traversing cross-points.

14. The network of claim 13 wherein said cross-point switching elements comprise two-by-two cross-point switches.

15. The network of claim 13 wherein each cross-point switching element has an even number of coupled active lightwave micro-resonators and can assume an electrical ON state or an electrical OFF state under the control of said switching element control means.

16. The network of claim 14 wherein each cross-point switching element has an even number of coupled passive lightwave micro-resonators.

17. The network of claim 13 wherein each matrix has M input and M output light waveguides, where M is an integer of four or more, and M² cross-point switches.

18. The network of claim 13 wherein each matrix has a group of output ports and preserves the spatial arrangement of incoming non-resonant signals at said output ports.

19. The network of claim 13 wherein said cross-point light-switching elements comprise semiconductor bulk-heterostructure or multiple-quantum-well electrotransparent resonators that have high optical absorption in the injected-current-OFF state and low optical absorption in the injected-current-ON state.

20. The network of claim 14 wherein said cross-point light-switching elements comprise semiconductor bulk-heterostructure or multiple-quantum-well electrotransparent resonators that have high optical absorption in the injected-current-OFF state and low optical absorption in the injected-current-ON state.

27. The network of claim 13 wherein each lightwave micro-resonator includes a p-i-n microdisk diode.

44. The network of claim 13 wherein said lightwave micro-resonators comprise micro-rings.

21. A wavelength-division-multiplexed routing network comprising:

(a) at least one light signal routing matrix having a number of light waveguides and an array of lightwave micro-resonator light-switching elements associated with cross-points between non-intersecting light waveguide portions, and wherein said light-switching elements of each matrix are responsive to a particular wavelength of light and are not responsive to other wavelengths of light that may be assigned to other matrices of said routing network; and

(b) switching element control means for causing selected light-switching elements to assume a cross state for switching resonant light across associated cross-points, or a bar state for forwarding light without traversing cross-points.

22. The network of claim 21 wherein said cross-point switching elements comprise two-by-two cross-point switches.

23. The network of claim 21 wherein each cross-point switching element has an even number of coupled active lightwave micro-resonators and can assume an electrical ON state or an electrical OFF state under the control of said switching element control means.

24. The network of claim 21 wherein each cross-point switching element has passive lightwave micro-resonators along with active electro-optic index changing switching means.

25. The network of claim 22 wherein each cross-point switching element has passive lightwave micro-resonators along with active electro-optic index-changing shunt switching means.

28. The network of claim 21 wherein each lightwave micro-resonator includes a p-i-n microdisk diode.

29. The network of claim 21 wherein each cross-point switching element has passive lightwave micro-resonators along with active electro-optic index-changing shunt switching means.

30. The network of claim 22 wherein each cross-point switching element has passive lightwave micro-resonators along with active electro-optic index changing shunt switching means.

31. The network of claim 21 wherein each matrix has M input and M output light waveguides, where M is an integer of four or more, and M² cross-point switches.

32. The network of claim 21 wherein each matrix has a group of output ports and preserves the spatial arrangement of incoming non-resonant signals at said output ports.

33. The network of claim 21 wherein said cross-point switching elements comprise semiconductor bulk-heterostructure or multiple-quantum-well electrotransparent micro-resonators that have low absorption in the electrical ON and OFF states.

45. The network of claim 21 wherein said lightwave micro-resonators comprise micro-rings.

34. A wavelength-division-multiplexed routing network comprising:

(a) a plurality of cascaded optical light transmissive switching matrices connected together in optical series, each matrix including a number of light-switching elements, each light-switching element including passive lightwave micro-resonators associated with cross-points between non-intersecting light waveguide portions of said matrices, and electro-optical switch means for selectively applying incoming light signals to selected lightwave micro-resonators or alternatively, shunting incoming light signals around non-selected lightwave micro-resonators, and wherein said lightwave micro-resonators of each matrix are responsive to a particular wavelength of light assigned to a particular matrix of the routing network and are unresponsive to wavelengths assigned to other matrices of the network; and

(b) switching element control means for controlling said electro-optic switch means for preventing application of incoming light signals to non-selected lightwave micro-resonators.

35. The network of claim 34 wherein said light-switching elements comprise two-by-two cross-point switches.

36. The network of claim 34 wherein each electro-optic switch means includes a one-by-two switch coupled in series with a two-by-one switch.

37. The network of claim 35 wherein each electro-optic switch means includes a one-by-two switch coupled in series with a two-by-one switch.

46. The network of claim 34 wherein said lightwave micro-resonators comprise micro-rings.

38. An optical switching matrix comprising:

(a) a matrix including a number of light-switching elements including passive lightwave micro-resonators associated with cross-points between non-intersecting light waveguide portions of the matrix and electro-optical switch means for selectively applying incoming light signals to selected passive lightwave micro-resonators or alternatively, shunting incoming light signals around said selected passive lightwave micro-resonators; and

(b) switching element control means for controlling said electro-optic switch means for preventing application of incoming light signals to non-selected micro-resonators.

39. The network of claim 38 wherein said light-switching elements comprise two-by-two cross-point switches.

40. The network of claim 38 wherein each two-by-two cross-point switch includes a one-by-two switch coupled in series with a two-by-one switch.

47. The network of claim 38 wherein said lightwave micro-resonators comprise micro-rings.

41. A wavelength-division-multiplexed routing network comprising:

(a) a plurality of cascaded optical matrix switches connected together in optical series, each matrix including a number of light waveguides and an array of cross-point light-switching elements associated with cross-points between non-intersecting light waveguide portions, and wherein said light-switching elements of each array are responsive to a particular wavelength of light assigned to a particular matrix of the routing network and are unresponsive to other wavelengths assigned to other matrices of the routing network; and

(b) switching element control means for causing selected light-switching elements to assume a cross state for switching light across associated cross-points, or a bar state for forwarding light without traversing cross-points.

42. The network of claim 41 wherein said cross-point switching elements comprise two-by-two cross-point switches.