Reduced diameter single mode optical fibers with high mechanical reliability

Patent metadata

Field	Value
Publication number	US-11733453-B2
Application number	US-202117315831-A
Country	US
Kind code	B2
Filing date	May 10, 2021
Priority date	May 12, 2020
Publication date	Aug 22, 2023
Grant date	Aug 22, 2023

Abstract

The optical fibers disclosed is a single mode optical fiber comprising a core region and a cladding region surrounding and directly adjacent to the core region. The core region can have a radius r1 in a range from 3 μm to 7 μm and a relative refractive index profile Δ1 having a maximum relative refractive index Δ1max in the range from 0.25% to 0.50%. The cladding region can include a first outer cladding region and a second outer cladding region surrounding and directly adjacent to the first outer cladding region. The first outer cladding region can have a radius r4a. The second outer cladding region can have a radius r4b less than or equal to 45 μm and comprising silica based glass doped with titania.

First claim

What is claimed is:

1. A single mode optical fiber, comprising:
a core region, the core region having a radius r 1 in a range from 3 μm to 7 μm and a relative refractive index profile Δ 1 having a maximum relative refractive index Δ 1max in the range from 0.25% to 0.50%; and
a cladding region surrounding and directly adjacent to the core region, the cladding region including a first outer cladding region and a second outer cladding region surrounding and directly adjacent to the first outer cladding region, the first outer cladding region having a radius r 4a , the second outer cladding region having a radius r 4b less than or equal to 45 μm, a relative refractive index Δ 4b greater than 0.20%, and comprising silica based glass doped with titania.

2. The single mode optical fiber of claim 1 , wherein the radius r 1 is in a range from 3.5 μm to 6.0 μm.

3. The single mode optical fiber of claim 1 , wherein the relative refractive index profile Δ 1 is a graded-index relative refractive index profile.

4. The single mode optical fiber of claim 1 , wherein the relative refractive index profile Δ 1 is a step-index relative refractive index profile.

5. The single mode optical fiber of claim 1 , wherein the maximum relative refractive index Δ 1max is in the range from 0.30% to 0.45%.

6. The single mode optical fiber of claim 1 , wherein the cladding region includes an inner cladding region surrounding and directly adjacent to the core region, the inner cladding region having a radius r 2 , a thickness (r 2 -r 1 ) in a range from 2 μm to 8 μm and a relative refractive index Δ 2 in a range from −0.10% to 0.10%.

7. The single mode optical fiber of claim 6 , wherein the cladding region further comprises a depressed-index cladding region surrounding and directly adjacent to the inner cladding region, the depressed-index cladding region having a radius r 3 , a thickness (r 3 −r 2 ) in a range from 3 μm to 10 μm, and a relative refractive index Δ 3 in a range from −0.70% to −0.20%.

8. The single mode optical fiber of claim 7 , wherein the thickness (r 3 −r 2 ) in a range from 4 μm to 8 μm.

9. The single mode optical fiber of claim 7 , wherein the depressed-index cladding region has a has a trench volume V 3 in a range from 30% Δ-μm 2 to 80%Δ-μm 2 .

10. The single mode optical fiber of claim 7 , wherein the first outer cladding region surrounds and is directly adjacent to the depressed-index cladding region.

11. The single mode optical fiber of claim 1 , wherein the first outer cladding region has a relative refractive index Δ 4a that is in the range from −0.10% to 0.10%.

12. The single mode optical fiber of claim 1 , wherein the second outer cladding region has a titania concentration in a range from 5 wt % to 20 wt %.

13. The single mode optical fiber of claim 1 , wherein the radius r 4b is less than or equal to 40 μm.

14. The single mode optical fiber of claim 1 , wherein the second outer cladding region has a thickness (r 4b −r 4a ) in a range from 2 μm to 30 μm.

15. The single mode optical fiber of claim 1 , further comprising:
a primary coating surrounding and directly adjacent to the second outer cladding region, the primary coating having a radius r 5 less than or equal to 65 μm, a spring constant χ p less than 1.2 MPa, an in situ modulus in the range from 0.05 MPa to 0.30 MPa, and a thickness (r 5 −r 4 ) less than 30 μm.

16. The single mode optical fiber of claim 15 , wherein the spring constant χ p is less than 0.8 MPa.

17. The single mode optical fiber of claim 15 , wherein the thickness (r 5 −r 4 ) is less than 20 μm.

18. The single mode optical fiber of claim 15 , wherein the primary coating is a cured product of a coating composition comprising:
a radiation-curable monomer;
an adhesion promoter, the adhesion promoter comprising an alkoxysilane compound or a mercapto-functional silane compound; and
an oligomer, the oligomer comprising:
a polyether urethane acrylate compound having the molecular formula:

wherein
R 1 , R 2 and R 3 are independently selected from linear alkylene groups, branched alkylene groups, or cyclic alkylene groups;
y is 1, 2, 3, or 4; and
x is between 40 and 100; and

a di-adduct compound having the molecular formula:

wherein the di-adduct compound is present in an amount of at least 1.0 wt % in the oligomer.

19. The single mode optical fiber of claim 18 , wherein the oligomer is the cured product of a reaction between:
a diisocyanate compound;
a hydroxy (meth)acrylate compound; and
a polyol compound, said polyol compound having unsaturation less than 0.1 meq/g;
wherein said diisocyanate compound, said hydroxy (meth)acrylate compound and said polyol compound are reacted in molar ratios n:m:p, respectively, wherein n is in the range from 3.0 to 5.0, m is within ±15% of 2n−4, and p is 2.

20. The single mode optical fiber of claim 15 , further comprising:
a secondary coating surrounding and directly adjacent to the primary coating, the secondary coating having a radius r 6 less than or equal to 85 μm, a Young's modulus greater than 1600 MPa and a thickness (r 6 −r 5 ) less than 30 μm.

21. The single mode optical fiber of claim 20 , wherein the radius r 6 is less than or equal to 80 μm.

22. The single mode optical fiber of claim 20 , wherein the thickness (r 6 −r 5 ) is less than 20 μm.

23. The single mode optical fiber of claim 20 , wherein the secondary coating is the cured product of a composition comprising:
an alkoxylated bisphenol-A diacrylate monomer in an amount greater than 55 wt %, the alkoxylated bisphenol-A diacrylate monomer having a degree of alkoxylation in the range from 2 to 16; and
a triacrylate monomer in an amount in the range from 2.0 wt % to 25 wt %, the triacrylate monomer comprising an alkoxylated trimethylolpropane triacrylate monomer having a degree of alkoxylation in the range from 2 to 16 or a tris[(acryloyloxy)alkyl] isocyanurate monomer.

24. The single mode optical fiber of claim 20 , wherein a ratio R ps of the thickness (r 5 −r 4 ) of the primary coating to the thickness (r 6 −r 5 ) of the secondary coating is in a range from 0.90 to 1.50.

25. The single mode optical fiber of claim 1 , wherein the single mode optical fiber has a fiber cutoff wavelength χ CF less than 1310 nm.

26. The single mode optical fiber of claim 1 , wherein the single mode optical fiber has a mode field diameter (MFD) greater than 8.2 μm at 1310 nm.

27. The single mode optical fiber of claim 1 , wherein the single mode optical fiber has a bend loss at 1550 nm, as determined by a mandrel wrap test using a mandrel with a diameter of 10 mm, less than 0.5 dB/turn.

Assignees

• Corning Inc

Inventors

• Bennett Kevin Wallace
• Bickham Scott Robertson
• Tandon Pushkar
• Tandon Ruchi Sarda
• Yang Bin

Classifications

• G02B6/12 Primary

  of the integrated circuit kind (electric integrated circuits H10B, H10D84/00 - H10D89/00, H10F19/00, H10F39/00, H10H29/00, H10K19/00, H10K39/00, H10K59/00, H10N19/00, H10N39/00, H10N59/00, H10N69/00, H10N79/00, H10N89/00) · CPC title

• C03C13/045

  Silica-containing oxide glass compositions · CPC title

• C03C25/105

  Organic claddings · CPC title

• C08F22/1006

  of polyhydric alcohols or polyhydric phenols, e.g. ethylene glycol dimethacrylate · CPC title

• C08F22/14

  Esters having no free carboxylic acid groups · CPC title