Optical fiber with large effective area and low bending loss

Patent metadata

Field	Value
Publication number	US-9851499-B2
Application number	US-201715435679-A
Country	US
Kind code	B2
Filing date	Feb 17, 2017
Priority date	Jun 30, 2015
Publication date	Dec 26, 2017
Grant date	Dec 26, 2017

Abstract

An optical fiber with large effective area, low bending loss and low attenuation. The optical fiber includes a core, an inner cladding region, and an outer cladding region. The core region includes a spatially uniform updopant to minimize low Rayleigh scattering and a relative refractive index and radius configured to provide large effective area. The inner cladding region features a large trench volume to minimize bending loss. The core may be doped with Cl and the inner cladding region may be doped with F.

First claim

What is claimed is:

1. An optical fiber comprising:
a core region comprising Cl-doped silica glass having a chlorine concentration greater than 1.5 wt %, said core region having an outer radius r 1 in the range from 6.0 microns to 10.0 microns and a relative refractive index Δ 1 ;
an inner cladding region surrounding said core region, said inner cladding region having an outer radius r 2 in the range from 15 microns to 40 microns, a relative refractive index Δ 2 , and a trench volume V Trench greater than 30%Δ-micron 2 ; and
an outer cladding region surrounding said inner cladding region, said outer cladding region having a relative refractive index Δ 3 such that Δ 1 >Δ 3 >Δ 2 ;
wherein said optical fiber has a cable cutoff of less than 1550 nm and an effective area at 1550 nm of at least 100 micron 2 .

2. The optical fiber of claim 1 , wherein the cable cutoff is less than 1500 nm.

3. The optical fiber of claim 1 , wherein the cable cutoff is less than 1450 nm.

4. The optical fiber of claim 1 , wherein said core is free of Ge.

5. The optical fiber of claim 1 , wherein said outer radius r 1 is in the range from 7.0 μm to 10.0 μm.

6. The optical fiber of claim 1 , wherein said relative refractive index Δ 1 is in the range from 0.08% to 0.30%.

7. The optical fiber of claim 1 , wherein said relative refractive index Δ 1 exceeds said relative refractive index Δ 2 by at least 0.20%.

8. The optical fiber of claim 1 , wherein said outer radius r 2 in the range from 24 μm to 35 μm.

9. The optical fiber of claim 1 , wherein said relative refractive index Δ 2 is in the range from −0.25% to 0%.

10. The optical fiber of claim 1 , wherein said relative refractive index Δ 3 is in the range from −0.20% to 0.10%.

11. The optical fiber of claim 1 , wherein said relative refractive index Δ 3 exceeds said relative refractive index Δ 2 by at least 0.08%.

12. The optical fiber of claim 1 , wherein said relative refractive index Δ 3 exceeds said relative refractive index Δ 2 by at least 0.10%.

13. The optical fiber of claim 1 , wherein said relative refractive index Δ 3 exceeds said relative refractive index Δ 2 by at least 0.12%.

14. The optical fiber of claim 1 , wherein said relative refractive index Δ 3 exceeds said relative refractive index Δ 2 by at least 0.15%.

15. The optical fiber of claim 1 , wherein said inner cladding region is directly adjacent said core.

16. The optical fiber of claim 15 , wherein said outer cladding region is directly adjacent said inner cladding region.

17. The optical fiber of claim 1 , wherein said effective area at 1550 nm is at least 130 μm 2 .

18. The optical fiber of claim 1 , wherein said effective area at 1550 nm is at least 150 μm 2 .

19. The optical fiber of claim 1 , wherein said optical fiber has a bending loss at 1550 nm, determined from a mandrel wrap test using a mandrel with a diameter of 20 mm, of less than 3.5 dB/turn.

20. The optical fiber of claim 1 , wherein said bending loss at 1550 nm, determined from a mandrel wrap test using a mandrel with a diameter of 20 mm, of less than 1.0 dB/turn.

21. The optical fiber of claim 1 , wherein said Cl-doped core comprises 1.75 wt % to 2.75 wt % Cl.

22. The optical fiber of claim 1 , wherein said inner cladding region comprises fluorine-doped silica glass.

23. The optical fiber of claim 22 , wherein the concentration of fluorine in said fluorine-doped silica glass is in the range from 0.10 wt % to 0.50 wt %.

24. The optical fiber of claim 1 , wherein said fiber has an attenuation at 1550 nm less than 0.17 dB/km.

25. The optical fiber of claim 1 , wherein said trench volume V Trench is greater than 50% Δmicron 2 .

26. The optical fiber of claim 1 , wherein said trench volume V Trench is greater than 100% Δmicron 2 .

27. The optical fiber of claim 1 , wherein said trench volume V Trench is greater than 150% Δmicron 2 .

28. The optical fiber of claim 1 , wherein said fiber has bending loss at 1550 nm, determined from a mandrel wrap test using a mandrel with a diameter of 60 mm, of less than 2.0 dB/100 turns.

29. The optical fiber of claim 1 , wherein said fiber has bending loss at 1550 nm, determined from a mandrel wrap test using a mandrel with a diameter of 60 mm, of less than 1.0 dB/100 turns.

30. The optical fiber of claim 1 , wherein said fiber has bending loss at 1550 nm, determined from a mandrel wrap test using a mandrel with a diameter of 60 mm, of less than 0.5 dB/100 turns.

31. The optical fiber of claim 1 , wherein said fiber has bending loss at 1550 nm, determined from a mandrel wrap test using a mandrel with a diameter of 60 mm, of less than 0.1 dB/100 turns.

32. The optical fiber of claim 1 , said fiber further comprising: (i) a primary coating having a Young's modulus less than 1 MPa; (ii) a secondary coating having a Young's modulus greater than 1200 MPa.

33. The optical fiber of claim 1 , said fiber further comprising: (i) a primary coating having a Young's modulus less than 0.5 MPa; (ii) a secondary coating having a Young's modulus greater than 1500 MPa.

34. The optical fiber of claim 1 , wherein said fiber has a dispersion of no more than 22 ps/nm/km at a wavelength of 1550 nm.

35. The optical fiber of claim 1 , said fiber has a wire mesh covered drum microbending loss less than 2 dB/km at a wavelength of 1550 nm.

36. The optical fiber of claim 1 , wherein said fiber has a wire mesh covered drum microbending loss less than 1 dB/km at a wavelength of 1550 nm.

37. The optical fiber of claim 1 , further comprising an offset region between said core region and said inner cladding region, said offset region having an outer radius r 4 and a relative refractive index Δ 4 such that r 1 <r 4 <r 2 and Δ 1 >Δ 4 >Δ 2 .

Assignees

• Corning Inc

Inventors

• Bookbinder Dana Craig
• Li Ming-Jun
• Matthews Iii Hazel Benton
• Mishra Snigdharaj Kumar
• Tandon Pushkar

Classifications

• C03C3/06

  with more than 90% silica by weight, e.g. quartz {(C03C3/045 takes precedence)} · CPC title

• C03C2201/12

  containing fluorine (C03C2201/14 takes precedence) · CPC title

• C03B2201/12

  doped with fluorine (C03B2201/14 takes precedence) · CPC title

• G02B6/0365

  arranged - - + · CPC title

• C03B2201/08

  doped with boron or fluorine or other refractive index decreasing dopant · CPC title