Devices, systems and methods for connecting a single mode fiber to a legacy multi-mode fiber

• US 20050002614A1
• Filed: 12/17/2003
• Published: 01/06/2005
• Est. Priority Date: 12/17/2002
• Status: Active Grant

• Current Assignee: II-VI Delaware, Inc. (Coherent Corp.)
• Original Assignee: Finisar Corporation (II-VI Incorporated)
• Inventors: Zhang, Yin, Wang, Steve, Zhong, Johnny
• Granted Patent: US 7,352,937 B2
• Time in Patent Office: Days
• US Class Current: 385/50
• CPC Class Codes: G02B 6/2835 formed or shaped by thermal treatment, e.g. couplers
• CPC Class Codes: G02B 6/32 having lens focusing means positioned between opposed fibre ends with lens being an integral part of the single fibre end G02B6/262
• CPC Class Codes: G02B 6/3801 Permanent connections, i.e. wherein fibres are kept aligned by mechanical means splices by bonding G02B6/255; fusion splices G02B6/2551

Abstract

Exemplary embodiments of the present invention provide for methods to launch data signals from single mode fiber optic cable into legacy multimode fiber optic cable. In one exemplary embodiment, a single mode fiber is offset slightly from the axis of a multimode fiber, thus only exciting the outer mode of the multimode fiber. In an alternate exemplary embodiment, a core portion of the single mode fiber is exposed, heated, and fused with a cladding portion of the multimode fiber. In yet another alternate exemplary embodiment, various lenses can be used to collimate and focus light signals from single mode fibers into multimode fibers, and vice versa. In these exemplary embodiments, the transmitted light signals can be in the range of from 1470 to about 1610 nm with, for example, a 20 nm channel separation. Other wavelengths and channel separations are also possible.

Claims

1. A device for coupling a light signal from a single mode fiber having a first fiber axis into a multimode fiber having a second fiber axis, said device comprising a first end, a second end disposed from said first end, and a hole extending between said first end and said second end and having an hole axis, said first end receives the single mode fiber so that the first fiber axis is offset from said hole axis and said second end receives the multimode fiber so that the second fiber axis is offset from the first fiber axis.

2. The device of claim 1, further comprising a filler material disposed within at least a part of said hole, said filler materials aiding with securely retaining the single mode fiber and the multimode fiber in said hole.

3. The device of claim 1, wherein the single mode fiber transmits data signals in a wavelength range of from about 1470 nanometers to about 1610 nanometers.

4. The device of claim 1, wherein the single mode fiber transmits coarse wavelength division multiplexed (CWDM) signals.

5. The device of claim 1, wherein the single mode fiber transmits data signals have a channel spacing of approximately 20 nanometers.

6. A system for coupling a light signal from a single mode fiber having a first fiber axis into a multimode fiber having a second fiber axis, said system comprising:

a first ferrule having a first ferrule axis, said ferrule encasing said single mode fiber so that said first fiber axis is offset from said first ferrule axis;

a second ferrule having a second ferrule axis, said second ferrule encasing the multimode fiber so that said second ferrule axis is aligned with the second fiber axis and offset from the first fiber axis.

7. The system of claim 6, wherein said multimode fiber interference fits with said second ferrule.

8. The system of claim 6, wherein said second ferrule at least partially surrounds said first ferrule.

9. The system of claim 6, further comprising a filler material at least partially contacting said first ferrule and said second ferrule.

10. A method for coupling a light signal from a single mode fiber to a multimode fiber, said method comprising:

positioning the single mode fiber within a ferrule, the single mode fiber having a first fiber axis and said ferrule having a first ferrule axis; and

positioning the multimode fiber, having a second fiber axis, within said ferrule so that said first fiber axis aligns with a point on the multimode fiber offset a distance from said second fiber axis.

11. The method of claim 10, further comprising locating an end of the single mode fiber within a second ferrule having a second ferrule axis and a hole having a hole axis, said second ferrule being disposed within said ferrule upon positioning the single mode fiber within said ferrule.

12. The method of claim 11, further comprising interference fitting said end of the single mode fiber within said second ferrule.

13. The method of claim 11, further comprising aligning said second ferrule axis with said second fiber axis.

14. The method of claim 11, further comprising aligning said hole axis with said point on the multimode fiber.

15. The method of claim 10, further comprising interference fitting the multimode fiber within said ferrule.

16. The method of claim 10, further comprising depositing a filler material within said ferrule.

17. The method of claim 10, wherein said single mode fiber is capable of transmitting data signals in a wavelength range of from about 1470 nanometers to about 1610 nanometers.

18. The method of claim 17, wherein said data signals are coarse wavelength division multiplexed (CWDM) signals.

19. The method of claim 18, wherein said CWDM data signals have a channel spacing of approximately 20 nanometers.

20. A device for coupling a light signal from a single mode fiber having a first fiber core and a first cladding layer at least partially surrounding the core into a multimode fiber having a second fiber core and a second cladding layer, said device comprising a first end, a second end disposed from said first end, and a hole extending between said first end and said second end that receives the single mode fiber and the multimode fiber when a first fiber portion of the first fiber core of the single mode fiber is joined to a second fiber portion of the second cladding layer of the multimode fiber to form a fused section.

21. The device as recited in claim 20, wherein said fused section is heated and stretched during joining of said first fiber portion of the first fiber core with said second fiber portion of the multimode fiber.

22. The system of claim 20, further comprising a filler material deposited within at least a portion of said hole.

23. The system of claim 20, wherein the single mode fiber transmits data signals in a wavelength range of from about 1470 nanometers to about 1610 nanometers.

24. The system of claim 23, wherein said data signals are coarse wavelength division multiplexed (CWDM) signals having channel spacing of approximately 20 nanometers.

25. A method for coupling a light signal from a single mode fiber to a multimode fiber, said method comprising:

removing a first cladding layer from the single mode fiber to expose a fiber core;

contacting said fiber core of the single mode fiber to a cladding layer of the multimode fiber; and

heating and stretching the single mode fiber and the multimode fiber until said fiber core fuses with said cladding layer of the multimode fiber to form a fused section.

26. The method of claim 25, further comprising encasing said fused section in a ferrule.

27. The method of claim 26, further comprising filling said ferrule with a filler material.

28. The method of claim 26 wherein said single mode fiber transmits data signals in a wavelength range of from about 1470 nanometers to about 1610 nanometers.

29. The method of claim 29, wherein said data signals are coarse wavelength division multiplexed (CWDM) signals having a channel spacing of approximately 20 nanometers.

30. A system for coupling a light signal from a single mode fiber into a multimode fiber, said system comprising:

a first collimating lens in optical communication with the single mode fiber;

a second collimating lens in optical communication with the multimode fiber; and

a focusing lens disposed between said first collimating lens and said second collimating lenses, said focusing lens focusing a light signal from said single mode fiber onto said multimode fiber.

31. The system of claim 30, wherein the single mode fiber transmits data signals in a wavelength range of from about 1470 nanometers to about 1610 nanometers.

32. The system of claim 31, wherein the data signals are coarse wavelength division multiplexed (CWDM) signals.

33. The system of claim 32, wherein the CWDM data signals have a channel spacing of approximately 20 nanometers.

34. A method for coupling a light signal from a single mode fiber to a multimode fiber, said method comprising:

positioning a single mode fiber, at least one lens and a multimode fiber having an axis; and

fixing a position of the single mode fiber, said at least one lens and said multimode fiber such that the light signal is focused from said single mode fiber, through said at least one lens onto an area of said multimode fiber offset from said axis.

35. The method of claim 34, wherein said single mode fiber transmits data signals in a wavelength range of from about 1470 nanometers to about 1610 nanometers.

36. The method of claim 35, wherein said data signals are coarse wavelength division multiplexed (CWDM) signals.

37. The method of claim 36, wherein said CWDM data signals have a channel spacing of approximately 20 nanometers.