Universal optical fibers for optical fiber connectors

1. An optical fiber for use as a stub fiber in an optical fiber connector comprising:

a segmented core with a relative refractive index Δ 1 in the range 0.3%≦Δ 1 ≦2.5% and having a substantially step-index single-mode segment with a radius r 1 in the range 2.5 μm≦r 1 ≦5 μm and a relative refractive index Δ s or Δ s +Δ t in the range 0.2%≦{Δ s or Δ s +Δ t }≦0.4%, and at least one alpha-profile multimode segment having a radius r 0 in the range 10 μm≦r 0 ≦50 μm and a profile parameter α in the range 1.8≦α≦4.1;

a cladding surrounding the segmented core, the cladding having an inner cladding segment of width w in the range 5 μm≦w≦20 μm and relative refractive index Δ 2 , and an outer cladding segment having a relative refractive index Δ 3 , wherein 1.5%≦Δ 2 ≦Δ 3 ; and

a length L in the range from 10 mm to 20 mm.

2. The optical fiber according to claim 1 , wherein 0.4%≦Δ 1 ≦2%.

3. The optical fiber according to claim 1 , wherein 22 μm≦r 0 ≦35 μm.

4. The optical fiber according to claim 1 , wherein 1.9≦α≦2.5.

5. An optical fiber connector, comprising:

the optical fiber according to claim 1 having a first end and operably supported by a first alignment member; and

a field optical fiber having a second end and operably supported relative to the first alignment member by a second alignment member such that the respective first and second ends of the stub fiber and field optical fiber are operably aligned and interfaced.

6. The optical fiber connector according to claim 5 , wherein the length L of the stub fiber is in the range from 15 mm to 20 mm.

7. The optical fiber connector according to claim 5 , further comprising a splicing member configured to operably align and interface the stub fiber and the single-mode field optical fiber.

8. The optical fiber connector according to claim 7 , wherein the splicing member further comprises an interior that contains an index-matching material.

9. The optical fiber connector according to claim 5 , wherein the field optical fiber is either a single mode fiber or a multimode fiber.

10. The optical fiber connector according to claim 5 , having a return loss that is less than −40 dB.

11. An optical fiber for use as a stub fiber in an optical fiber connector comprising:

a segmented core having a substantially step-index single-mode segment and at least one multimode segment having an alpha profile, wherein the single-mode segment has an associated mode field diameter substantially the same as a conventional single-mode optical fiber, and has substantially the same or a smaller group index difference Δn g as compared to the conventional single mode fiber;

wherein the at least one multimode segment has radius and a numerical aperture NA MM that substantially match that of a conventional multimode optical fiber; and

wherein the stub fiber has a length L in the range from 10 mm to 20 mm.

12. The optical fiber according to claim 11 , wherein the substantially step-index single-mode segment has a radius r 1 in the range 2.5 μm≦r 1 ≦5 μm and a relative refractive index Δ s or Δ s +Δ t in the range 0.2%≦{Δ s or Δ s +Δ t }≦0.4%.

13. An optical fiber connector, comprising:

the optical fiber according to claim 10 serving as said stub fiber and having a first end and operably supported by a first alignment member; and

a field optical fiber having a second end and operably supported relative to the first alignment member by a second alignment member such that the respective first and second ends of the stub fiber and field optical fiber are operably aligned and interfaced.

14. The optical fiber connector according to claim 13 , wherein the length L of the stub fiber is in the range from 15 mm to 20 mm.

15. The optical fiber connector according to claim 13 , further comprising a splicing member configured to operably align and interface the stub fiber and the single-mode field optical fiber.

16. The optical fiber connector according to claim 13 , wherein the splicing member further comprises an interior that contains an index-matching material.

17. The optical fiber connector according to claim 13 , wherein the field optical fiber is either a standard single mode fiber, or a multimode fiber.

18. The optical fiber connector according to claim 13 , having a return loss that is less than −40 dB.

19. An optical fiber connector for connecting to either a single-mode optical fiber or a multi-mode optical fiber, comprising:

a stub fiber having a length L of between 10 mm and 20 mm, a first end and a core having single-mode and multimode segments, wherein the single-mode segment has a substantially step-index profile, a mode field diameter substantially the same as that of a conventional single-mode optical fiber and has substantially the same or a smaller group index difference Δn g as compared to the conventional single mode fiber, and wherein the multimode segment has an alpha profile, a radius r 0 in the range 22 μm≦r 0 ≦35 μm, and a numerical aperture NA MM that substantially match that of a conventional multimode optical fiber;

a first alignment member that operably supports the stub fiber; and

a field optical fiber having a second end and that is operably supported relative to the first alignment member by a second alignment member such that the respective first and second ends of the stub fiber and field optical fiber are operably aligned and interfaced.

20. The optical fiber connector according to claim 19 , further comprising a splicing member configured to operably align and interface the stub fiber and the single-mode field optical fiber.

21. The optical fiber connector according to claim 19 , wherein the splicing member further comprises an interior that contains an index-matching material.

22. The optical fiber connector according to claim 19 , wherein the field optical fiber is either a standard single mode fiber, or a multimode fiber.

23. The optical fiber connector according to claim 19 , having a return loss that is less than −40 dB.