Low bend loss optical fiber

Patent metadata

Field	Value
Publication number	US-10082622-B2
Application number	US-201715812560-A
Country	US
Kind code	B2
Filing date	Nov 14, 2017
Priority date	Mar 29, 2016
Publication date	Sep 25, 2018
Grant date	Sep 25, 2018

Abstract

Disclosed herein are optical waveguide fibers comprising: (I) a core comprising an outer radius r1, a maximum refractive index delta percent Δ1max and core alpha, α, of larger than 5; and (II) a cladding surrounding the core, the cladding comprising: (i) an inner cladding region having outer radius r2 and refractive index delta percent Δ2, wherein Δ1max>Δ2; (ii) a trench region surrounding the inner cladding region, the trench region having an outer radius, r3 where r3≥10 microns and refractive index delta percent Δ3; and (iii) an outer cladding region having chlorine concentration of ≥1.2 wt. % surrounding the trench region and comprising refractive index delta percent Δ4, wherein Δ1max>Δ4 and Δ2>Δ3, and Δ4>Δ3 and wherein the difference between Δ4 and Δ3 is ≥0.12 percent.

First claim

What is claimed is:

1. A single mode optical fiber comprising:
(I) a core having outer radius r 1 , a maximum refractive index delta percent Δ 1max and core alpha>5;
(II) a cladding surrounding the core, the cladding comprising
(i) inner cladding region having outer radius r 2 and refractive index delta percent Δ 2 , wherein Δ 1max >Δ 2 ; and
(ii) a trench region surrounding the inner cladding region, the trench region having an outer radius r 3 >10 microns and refractive index delta percent Δ 3 ; and
(iii) an outer cladding region having chlorine concentration larger than 1.2 wt. % surrounding the trench region and comprising refractive index delta percent Δ 4 ; wherein Δ 1max >Δ 4 and Δ 2 >Δ 3 , and Δ 4 >Δ 3 and wherein the Δ 4 −Δ 3 ≥0.12 percent, and said fiber exhibits a MAC number ≥7.25 at 1310 nm wavelength, cable cutoff of less than 1260 nm, and bend loss at 1550 nm for a 15 mm diameter mandrel of less than 0.5 dB/turn, and 1300 nm≤λ 0 ≤1324 nm, where λ 0 is the zero dispersion wavelength.

2. The optical fiber of claim 1 , wherein the MAC number ≥7.6 at 1310 nm wavelength.

3. The optical fiber of claim 1 , wherein the MAC number ≥7.7 at 1310 nm wavelength.

4. The optical fiber of claim 1 , wherein the bend loss for a 30 mm mandrel diameter is less than 0.005 dB/turn at 1550 nm.

5. The optical fiber of claim 1 , wherein the bend loss for a 30 mm mandrel diameter is less than 0.003 dB/turn at 1550 nm.

6. The optical fiber of claim 1 , wherein a maximum refractive index delta percent Δ 1 <0.65%.

7. The optical fiber of claim 1 , wherein refractive index delta percent Δ 3 is between −0.4% and 0.1%.

8. The Optical fiber of claim 1 , wherein the trench region has a width W 1 between 4 microns and 22 microns.

9. The optical fiber of claim 1 , wherein the profile volume, |V 3 | of the trench region is at least 30% Δmicron 2 .

10. The optical fiber of claim 1 , wherein the profile volume, |V 3 | of the trench region is at least 45% Δmicron 2 .

11. The optical fiber of claim 1 , wherein Δ 4 −Δ 3 ≥0.15 percent.

12. The optical fiber of claim 1 , wherein Δ 1max −Δ 2 0.25 percent, and Δ 1max −Δ 3 ≥0.35; and Δ 2 −Δ 3 ≥0.08 percent.

13. The optical fiber of claim 12 , wherein 0.15%≤Δ 4 −Δ 3 ≤0.4% delta.

14. The optical fiber of claim 1 , wherein the core has less than 10 wt. % germania.

15. The optical fiber of claim 1 , wherein the maximum germania concentration in the core region, [Ge02] core-max , in weight percent is 4 wt. %≤[Ge02] core-max ≤13 wt. %.

16. The optical fiber of claim 1 , wherein the maximum germania concentration in the core region, [Ge02] core-max , in weight percent is 6 wt. %≤[Ge02] core-max ≤12 wt %.

17. The optical fiber of claim 1 , wherein the maximum germania concentration in the core region, [Ge02] core-max ,in weight percent is 7 wt. %≤[Ge02] core-max ≤11 wt. %.

18. The optical fiber of claim 1 , wherein the maximum chlorine concentration in the core region, [Cl] core-max , in weight percent is 1 wt. %≤[Cl] core-max ≤7 wt. %.

19. The optical fiber of claim 1 , wherein the maximum chlorine concentration in the core region, [Cl] core-max , in weight percent is 1 wt. %≤[Cl] core-max ≤6 wt. %.

20. The optical fiber of claim 1 , wherein the maximum chlorine concentration in the core region, [Cl] core-max , in weight percent is 1.5 wt. %≤[Cl] core-max ≤6 wt. %.

21. The optical fiber of claim 1 , wherein the trench region contains 0 to 2 wt. % fluorine.

22. The optical fiber of claim 1 , wherein the outer cladding region comprises Cl concentration ≥1.5 weight percent.

23. The optical fiber of claim 1 , wherein the ratio of core radius to the inner cladding radius, 1.2<r 2 /r 1 <2.5.

24. The optical fiber of claim 1 , said fiber further exhibiting a wire mesh covered drum microbend loss at 1550 nm which is less than or equal to 0.05 dB/km.

25. The optical fiber of claim 1 , said fiber further exhibiting a wire mesh covered drum microbend loss at 1550 nm which is less than or equal to 0.01 dB/km.

26. The optical fiber of claim 1 , wherein the trench region is essentially free of fluorine and germania.

27. The optical fiber of claim 1 , wherein Δ 4 ≥Δ 2 for a radial position extending from r 3 to a radius of at least 30 microns.

28. The fiber of claim 1 , wherein said fiber exhibits an attenuation at 1550 nm which is less than or equal to 0.18 dB/km.

29. The fiber of claim 1 , wherein said fiber exhibits an attenuation at 1310 nm which is less than or equal to 0.32 dB/km.

30. The fiber of claim 1 , wherein the core alpha is greater than 10.

31. The optical fiber of claim 1 , wherein 9 microns<MFD at 1310 nm<9.5 microns.

32. The optical fiber of claim 1 , said fiber further exhibiting a basketweave microbend loss at −60° C. at 1550 nm which is less than or equal to 0.05 dB/km.

33. The optical fiber of claim 1 , said fiber further exhibiting a basketweave microbend loss at −60° C. at 1550 nm which is less than or equal to 0.01 dB/km.

34. The optical fiber of claim 1 , said fiber further is coated with primary and secondary coatings, wherein the outer diameter of the secondary coating is less than 250 microns.

35. The optical fiber of claim 34 , wherein the primary coating has Young's modulus of less than 1 MPa and the secondary coating has Young's modulus of greater than 1000 MPa.

36. The optical fiber of claim 1 , said fiber further is coated with primary and secondary coatings, wherein the outer diameter of the secondary coating is less than 210 microns.

37. The optical fiber of claim 36 , wherein the primary coating has Young's modulus of less than 1 MPa and the secondary coating has Young's modulus of greater than 1000 MPa.

38. The optical fiber of claim 1 , wherein the outer cladding region comprises a first outer cladding region with refractive index delta percent Δ4 and chlorine concentration larger than 1.2 wt. % ; and a second outer cladding region surrounding the first outer cladding region and comprising refractive index delta percent Δ5 such that Δ4>Δ5, the second outer cladding region having chlorine concentration of less than 0.5 wt. %.

39. The optical fiber of claim 38 , wherein viscosity of glass of said second outer cladding region is greater than the viscosity of glass of said first outer cladding region.

Assignees

• Corning Inc

Inventors

• Bookbinder Dana Craig
• Li Ming-Jun
• Mishra Snigdharaj Kumar
• Tandon Pushkar

Classifications

• G02B6/03672 Primary

  arranged - - + - · CPC title

• G02B6/0365

  arranged - - + · CPC title

• G02B6/02395

  Glass optical fibre with a protective coating, e.g. two layer polymer coating deposited directly on a silica cladding surface during fibre manufacture (G02B6/02052, G02B6/02057, G02B6/024, G02B6/032, G02B6/105, G02B6/14 take precedence; coating on fibre gratings G02B6/02104; multilayer core or cladding G02B6/036; reinforcing splice joints G02B6/2558; optical cables, i.e. comprising protective structures external to the protective coating such as a jacket or plural coated optical fibres G02B6/44; coating of glass to obtain optical fibres C03C25/104) · CPC title

• G02B6/02009

  Large effective area or mode field radius, e.g. to reduce nonlinear effects in single mode fibres · CPC title

• G02B6/02014

  Effective area greater than 60 square microns in the C band, i.e. 1530-1565 nm · CPC title