Low bend loss single mode optical fiber with bromine up-doped cladding

Patent metadata

Field	Value
Publication number	US-10215915-B2
Application number	US-201715714122-A
Country	US
Kind code	B2
Filing date	Sep 25, 2017
Priority date	Sep 30, 2016
Publication date	Feb 26, 2019
Grant date	Feb 26, 2019

Abstract

According to embodiments, an optical fiber may include a core portion comprising an outer radius rC and a maximum relative refractive index ΔCmax. A cladding may surround the core portion and include a low-index trench and an outer cladding. The low index trench may surround the core portion and includes an outer radius rT and relative refractive index ΔT. The outer cladding may surround and be in direct contact with the low-index trench. The outer cladding may be formed from silica-based glass comprising greater than 1.0 wt. % bromine and has a relative refractive index ΔOC, wherein ΔCmax>ΔOC>ΔT. The optical fiber may have a cable cutoff of less than or equal to 1530 nm. An attenuation of the optical fiber may be less than or equal to 0.185 dB/km at a wavelength of 1550 nm.

First claim

What is claimed is:

1. An optical fiber comprising:
a core portion comprising an outer radius r C and a maximum relative refractive index Δ Cmax relative to pure silica glass;
a cladding surrounding the core portion and comprising:
a low-index trench surrounding the core portion, the low-index trench comprising an outer radius r T and relative refractive index Δ T relative to pure silica glass; and
an outer cladding surrounding and in direct contact with the low-index trench, the outer cladding formed from silica-based glass comprising greater than 1.0 wt. % bromine and having a relative refractive index Δ OC relative to pure silica glass, wherein:
the optical fiber comprises a cable cutoff of less than or equal to 1530 nm;
Δ Cmax >Δ OC >Δ T ; and
an attenuation of the optical fiber is less than or equal to 0.185 dB/km at a wavelength of 1550 nm.

2. The optical fiber of claim 1 , wherein a mode field diameter MFD of the optical fiber is greater than 9 μm at a wavelength of 1310 nm.

3. The optical fiber of claim 1 , wherein a 15 mm diameter bend loss of the optical fiber is less than 0.5 dB/turn at 1550 nm.

4. The optical fiber of claim 1 , wherein a cable cutoff of the optical fiber is less than 1260 nm.

5. The optical fiber of claim 1 , wherein a zero dispersion wavelength λ 0 of the optical fiber is greater than or equal to 1300 nm and less than or equal to 1324 nm.

6. The optical fiber of claim 1 , wherein a concentration of bromine in the outer cladding is less than or equal to 3 wt. %.

7. The optical fiber of claim 1 , wherein a concentration of bromine in the outer cladding is greater than or equal to 1.2 wt. % and less than or equal to 2.0 wt. %.

8. The optical fiber of claim 1 , wherein Δ OC is greater than or equal to 0.1% and less than or equal to 0.4% relative to pure silica glass.

9. The optical fiber of claim 1 , wherein the low-index trench has a volume profile V T and |V T | is greater than or equal to 30% Δμm 2 .

10. The optical fiber of claim 1 , wherein the low-index trench is in direct contact with the core portion.

11. The optical fiber of claim 10 , wherein the core portion has an alpha profile and a is greater than or equal to 1 and less than or equal to 5.0.

12. The optical fiber of claim 10 , wherein:
the outer radius r C of the core portion is greater than or equal to 4 microns and less than or equal to 10 microns; and
the outer radius r T is greater than or equal to 14 microns and less than or equal to 25 microns.

13. The optical fiber of claim 1 , wherein the cladding further comprises an inner cladding surrounding the core portion and in direct contact with the core portion and the low-index trench, the inner cladding comprising an outer radius r IC and a relative refractive index Δ IC relative to pure silica glass, wherein Δ max >Δ IC and Δ IC >Δ T .

14. The optical fiber of claim 13 , wherein the core portion has an alpha profile and a is greater than or equal to 10.

15. The optical fiber of claim 13 , wherein:
the outer radius r C of the core portion is greater than or equal to 2.75 microns and less than or equal to 6 microns;
the outer radius r IC of the inner cladding is greater than or equal to 6.5 microns and less than or equal to 15 microns; and
the outer radius r T is greater than or equal to 12 microns and less than or equal to 25 microns.

16. An optical fiber comprising:
a core portion comprising an outer radius r C and a maximum relative refractive index Δ Cmax relative to pure silica glass;
a cladding surrounding the core portion and comprising:
a low-index trench surrounding the core portion, the low-index trench comprising an outer radius r T and relative refractive index Δ T relative to pure silica glass; and
an outer cladding surrounding and in direct contact with the low-index trench, the outer cladding formed from silica-based glass comprising greater than 0.25 wt. % of bromine or a compound of bromine and having a relative refractive index Δ OC relative to pure silica glass, wherein:
the optical fiber comprises a cable cutoff less than or equal to 1530 nm;
Δ Cmax >Δ OC >Δ T ; and
an axial stress of a region directly adjacent to the core portion is less than 2.5 MPa.

17. The optical fiber of claim 16 , wherein a mode field diameter MFD of the optical fiber is greater than 9 μm at a wavelength of 1310 nm.

18. The optical fiber of claim 16 , wherein a 15 mm diameter bend loss of the optical fiber is less than 0.5 dB/turn at 1550 nm.

19. The optical fiber of claim 16 , wherein a cable cutoff of the optical fiber is less than 1260 nm.

20. The optical fiber of claim 16 , wherein a zero dispersion wavelength λ 0 of the optical fiber is greater than or equal to 1300 nm and less than or equal to 1324 nm.

21. The optical fiber of claim 16 , wherein the low-index trench is in direct contact with the core portion.

22. The optical fiber of claim 21 , wherein the core portion has an alpha profile and a is greater than or equal to land less than or equal to 5.0.

23. The optical fiber of claim 21 , wherein:
the outer radius r C of the core portion is greater than or equal to 4 microns and less than or equal to 10 microns; and
the outer radius r T is greater than or equal to 14 microns and less than or equal to 25 microns.

24. The optical fiber of claim 16 , wherein the cladding further comprises an inner cladding surrounding the core portion and in direct contact with the core portion and the low-index trench, the inner cladding comprising an outer radius r IC and a relative refractive index Δ IC relative to pure silica glass, wherein Δ Cmax >Δ IC and Δ IC >Δ T .

25. The optical fiber of claim 24 , wherein the core portion has an alpha profile and a is greater than or equal to 10.

26. The optical fiber of claim 24 , wherein:
the outer radius r C of the core portion is greater than or equal to 2.75 microns and less than or equal to 7 microns;
the outer radius r IC of the inner cladding is greater than or equal to 6.5 microns and less than or equal to 15 microns; and
the outer radius r T is greater than or equal to 12 microns and less than or equal to 25 microns.

Assignees

• Corning Inc

Inventors

• Bookbinder Dana Craig
• Dawes Steven Bruce
• Li Ming-Jun
• Tandon Pushkar

Classifications

• C03B2201/31

  doped with germanium · CPC title

• G02B6/03616

  Optical fibres characterised both by the number of different refractive index layers around the central core segment, i.e. around the innermost high index core layer, and their relative refractive index difference · CPC title

• C03B2201/28

  doped with phosphorus · CPC title

• C03B37/014

  made entirely or partially by chemical means {, e.g. vapour phase deposition of bulk porous glass either by outside vapour deposition [OVD], or by outside vapour phase oxidation [OVPO] or by vapour axial deposition [VAD] (C03C17/02 takes precedence)} · CPC title

• C03B2201/42

  doped with titanium · CPC title