OPTICAL COUPLER INCLUDING MODE-MIXING

• US 20080240653A1
• Filed: 04/23/2007
• Published: 10/02/2008
• Est. Priority Date: 03/27/2007
• Status: Abandoned Application

• Current Assignee: II-VI Delaware, Inc. (Coherent Corp.)
• Original Assignee: II-VI Delaware, Inc. (Coherent Corp.)
• Inventors: Noble, Gayle L., King, Jonathan Paul, Abrahams, Paul Chetwode
• Application Number:
  US11/739,048
• Publication Number:
  US 20080240653A1
• Time in Patent Office: Days
• US Class Current: 385/28
• CPC Class Codes: G02B 6/14 Mode converters
• CPC Class Codes: G02B 6/2804 forming multipart couplers without wavelength selective elements, e.g. "T" couplers, star couplers

Abstract

A mode-mixer is used to introduce mode-mixing to an input in an optical coupler. As a result, modal noise effects are minimized in an output of the optical coupler. An example of a mode-mixer implemented includes a step index optical fiber which may or may not be coupled to a graded index optical fiber via a splice within an optical coupler. The splice may be a mechanical splice using connectors or a fused splice in some embodiments. The optical coupler may be included in a system for monitoring and/or analyzing a network.

Claims

1. An optical coupler comprising:

an input;

means for introducing mode-mixing optically coupled to the input;

a first output;

a second output; and

a fiber optic splitter configured to optically couple the input with the first output and the second output.

2. An optical coupler according to claim 1, wherein the means for introducing mode-mixing includes a step index optical fiber.

3. An optical coupler according to claim 2, wherein the input includes a graded index optical fiber, wherein the input further includes means for coupling optical energy between the step index optical fiber and the graded index optical fiber.

4. An optical coupler according to claim 3, wherein the means for coupling optical energy includes an optical fiber splice between the step index optical fiber and the graded index optical fiber.

5. An optical coupler according to claim 4, wherein the optical fiber splice includes a fusion splice between the step index optical fiber and the graded index optical fiber.

6. An optical coupler according to claim 4, wherein the optical fiber splice includes a mechanical splice between the step index optical fiber and the graded index optical fiber.

7. An optical coupler according to claim 6, wherein the mechanical splice includes a mated plug assembly between the step index optical fiber and the graded index optical fiber.

8. An optical coupler according to claim 7, wherein the mated plug assembly includes mated LC type optical connectors.

9. An optical coupler according to claim 1, wherein the first output includes a step index optical fiber.

10. An optical coupler according to claim 1, wherein the second output includes a step index optical fiber.

11. An optical coupler according to claim 1, wherein the optical coupler is associated with a predetermined split ratio.

12. An optical coupler according to claim 11, wherein the split ratio is between about 10:

90 and 50;

50.

13. An optical coupler according to claim 11, wherein the split ratio is about 20:

80.

14. An optical coupler according to claim 11, wherein the split ratio is about 30:

70.

15. An optical coupler according to claim 2, wherein a length of the step index optical fiber is at least about 2 centimeters.

16. An optical coupler according to claim 2, wherein a length of the step index optical fiber is between about 5 centimeters and about 100 centimeters.

17. An optical coupler according to claim 2, wherein a length of the step index optical fiber is between about 10 centimeters and about 20 centimeters.

18. An optical coupler according to claim 2, wherein a core diameter of the step index optical fiber is between about 25 and about 200 micron.

19. An optical coupler according to claim 2, wherein a core diameter of the step index optical fiber is about 50 micron.

20. An optical coupler according to claim 2, wherein a core diameter of the step index optical fiber is about 62.5 micron.

21. An optical coupler according to claim 1, wherein the first output includes a first output optical fiber, the second output includes a second output optical fiber, and the input includes an input optical fiber.

22. An optical coupler according to claim 1, wherein the means for introducing mode-mixing includes an attenuation device, surface coating, surface treatment, mechanical or optical perturbation, a doped fiber, or a roughness to a surface.

23. A Fibre Channel tap comprising the optical coupler according to claim 1.

24. A Fibre Channel tap comprising at least two optical couplers according to claim 1 and configured to support up to 10 gigabits-per-second.

25. A Fibre Channel tap comprising between about four and about 32 optical couplers according to claim 1.

26. A system comprising:

an optical coupler comprising;

an input;

means for introducing mode-mixing optically coupled to the input;

a first output;

a second output; and

a fiber optic splitter configured to optically couple the input with the first output and the second output;

a first electronic device optically coupled to the input of the optical coupler; and

a second electronic device optically coupled to the second output of the optical coupler.

27. A system according to claim 26, wherein the means for introducing mode-mixing includes a step index fiber.

28. A system according to claim 26, wherein the first electronic device includes a network host device and the second electronic device includes a network switch device.

29. A system according to claim 26, further comprising an analysis device coupled to the first output, the analysis device being configured to monitor and/or analyze data transmitted from the first electronic device to the second electronic device.

30. A system according to claim 29, wherein the analysis device includes a probe configured to monitor and/or analyze data transmitted from the first electronic device to the second electronic device at line rates of at least 4 gigabits-per-second.

31. A method for processing an optical signal transmitted in an optical communication link, the method comprising:

introducing mode-mixing to the optical signal; and

diverting a portion of the optical signal transmitted in the optical communication link.

32. A method according to claim 31, wherein the diverted portion of the optical signal has a waveform that substantially represents a waveform of the optical signal transmitted in the optical communication link.

33. A method according to claim 31, further comprising:

converting the diverted portion of the optical signal to an electrical signal; and

outputting the electrical signal to an electronic device.

34. A method according to claim 31, wherein the optical signal transmitted in the optical communication link is associated with a transmission rate of at least about 4 gigabits-per-second.

35. A method for analyzing an optical signal, comprising:

performing the acts of claim 31; and

analyzing the diverted portion of the optical signal.

36. A method according to claim 35, wherein the received optical data is analyzed for a mask margin associated with the received optical data.

37. A method according to claim 36, wherein the mask margin includes less than 5 percent mask degradation.

38. A method according to claim 35, wherein the analysis includes analysis of a network within which the optical data is transmitted.