Optical fiber with large mode field diameter and low microbending losses

• US 10,094,973 B2
• Filed: 06/27/2016
• Issued: 10/09/2018
• Est. Priority Date: 05/02/2013
• Status: Active Grant

• Current Assignee: Corning Incorporated
• Original Assignee: Corning Incorporated
• Inventors: Bickham, Scott Robertson, Lewis, Kevin Alton, Mishra, Snigdharaj Kumar, Ocampo, Manuela, Patterson, Joan Diana
• Primary Examiner(s): PENG, CHARLIE YU
• Application Number:
  US15/193,860
• Publication Number:
  US 20160306107A1
• Time in Patent Office: 834 Days
• Field of Search: None
• CPC Class Codes: C03C 25/1065 Multiple coatings
• CPC Class Codes: C03C 25/285 Acrylic resins
• CPC Class Codes: C03C 25/326 Polyureas; Polyurethanes
• CPC Class Codes: G02B 6/02009 Large effective area or mode field radius, e.g. to reduce nonlinear effects in single mode fibres
• CPC Class Codes: G02B 6/02395 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 Class Codes: G02B 6/0281 Graded index region forming part of the central core segment, e.g. alpha profile, triangular, trapezoidal core G02B6/0288, G02B6/0286 take precedence
• CPC Class Codes: G02B 6/03627 arranged - +
• CPC Class Codes: G02B 6/0365 arranged - - +

Abstract

Optical fibers having a mode field diameter at 1310 nm of at least 8.8 μm, wire mesh covered drum microbending losses at 1550 nm less than 0.03 dB/km, and a 2 m cutoff wavelength less than 1320 nm. The fibers may include a central core region, an inner cladding region, an outer cladding region, a primary coating with an in situ modulus less than 0.20 MPa and glass transition temperature less than −35° C., and a secondary coating with an in situ modulus greater than 1500 MPa. The fibers may further include a depressed index cladding region. The relative refractive index of the central core region may be greater than the relative refractive index of the outer cladding region may be greater than the relative refractive index of the inner cladding region. The fibers may be produced at draw speeds of 30 m/s or greater.

Claims

1. An optical waveguide fiber comprising:

a central core region having a radius r₁ and a relative refractive index Δ

₁(r) in % measured relative to pure silica, said relative refractive index Δ

₁(r) having a maximum Δ

_1max;

a cladding, said cladding including an inner cladding region surrounding said central core region and an outer cladding region surrounding said inner cladding region, said inner cladding region having an outer radius r₂>

8 μ

m and a relative refractive index Δ

₂(r) in % measured relative to pure silica, said relative refractive index Δ

₂(r) having a maximum Δ

_2max and a minimum Δ

_2min, said outer cladding region having a relative refractive index Δ

₄ in % measured relative to pure silica, said relative refractive index Δ

₄ being positive and less than said maximum Δ

_1max, said relative refractive index Δ

₄ exceeding said minimum Δ

_2min by at least 0.002%;

a primary coating surrounding said outer cladding region, said primary coating having an in situ modulus of less than 0.20 MPa and an in situ glass transition temperature of less than −

35°

C.; and

a secondary coating surrounding said primary coating, said secondary coating having an in situ modulus of greater than 1500 MPa

wherein said fiber exhibits a wire mesh covered drum microbending loss less than 0.030 dB/km at a wavelength of 1550 nm when wound around a mesh-covered aluminum drum with a diameter of 400 mm.

2. The fiber of claim 1, wherein said relative refractive index percent profile Δ

₁(r) is a super-Gaussian profile, said super-Gaussian profile being substantially described by the equation

3. The fiber of claim 1, wherein said relative refractive index percent profile Δ

₁(r) is an α

-profile, said α

-profile being substantially described by the equation

4. The fiber of claim 1, wherein said relative refractive index Δ

₄ is at least 0.010%.

5. The fiber of claim 1, wherein the width of said inner cladding region is between 3 μ

m and 13 μ

m.

6. The fiber of claim 1, wherein said relative refractive index Δ

₄ exceeds said minimum Δ

_2min by at least 0.02%.

7. The fiber of claim 1, wherein said cladding further comprises a depressed index cladding region between said inner cladding region and said outer cladding region, said depressed index cladding region having a relative refractive index Δ

₃(r) with a minimum Δ

_3min, said minimum Δ

_3min being less than said minimum Δ

_2min by at least 0.005%, said minimum Δ

_3min being less than said relative refractive index Δ

₄ by at least 0.010%.

8. The fiber of claim 1, wherein said fiber exhibits a mode field diameter greater than 8.8 μ

m at a wavelength of 1310 nm.

9. The fiber of claim 1, wherein said fiber exhibits a 2 m cutoff wavelength less than 1360 nm.

10. The fiber of claim 1, wherein said primary coating has an in situ glass transition temperature of less than −

45°

C.

11. The fiber of claim 1, wherein the outer diameter of said primary coating is less than 185 μ

m.

12. The fiber of claim 1, wherein said primary coating is the cured product of a primary composition that includes a urethane acrylate oligomer and a monomer selected from the group consisting of (meth)acrylates, N-vinyl amides, and epoxy acrylates.

13. The fiber of claim 12, wherein said primary composition comprises one or more monofunctional (meth)acrylate monomers in an amount of from about 5 to 95% by weight;

an N-vinyl amide monomer in an amount of from about 0.1 to 40% by weight; and

one or more difunctional urethane acrylate oligomers which comprise a polyol and an isocyanate, said oligomer present in an amount of from about 5 to 95% by weight, wherein the polyol in said oligomer is a polypropylene glycol and the isocyanate in said oligomer is an aliphatic diisocyanate.

14. The fiber of claim 12, wherein said primary composition comprises one or more monofunctional (meth)acrylate monomers in an amount of from about 40 to 65% by weight;

an N-vinyl amide monomer in an amount of from about 2 to 10% by weight; and

one or more polypropylene glycol-based difunctional urethane acrylate oligomers in an amount of from about 35 to 60% by weight.

15. The fiber of claim 1, wherein said secondary coating has an in situ modulus of 1800 MPa or greater.

16. The fiber of claim 1, wherein said secondary coating is the cured product of a secondary composition that lacks urethane-containing oligomers.

17. The fiber of claim 16, wherein said secondary composition comprises a monomer selected from the group consisting of alkoxylated bisphenol-A diacrylate, alkylene glycol acrylate, and epoxy diacrylate.

18. The fiber of claim 17, wherein said secondary composition comprises:

about 40 to 80% by weight of ethoxylated (4) bisphenol A monomer;

from about 0 to about 30% by weight of ethoxylated (10) bisphenol A monomer;

from about 0 to about 25% by weight of ethoxylated (30) bisphenol A monomer; and

from about 5 to 18% by weight of epoxy acrylate.

19. The fiber of claim 1, wherein said mode field diameter is greater than 9.0 μ

m at a wavelength of 1310 nm, said 2 m cutoff wavelength is less than 1320 nm, and said wire mesh covered drum microbending loss is less than 0.020 dB/km at a wavelength of 1550 nm when wound around a mesh-covered aluminum drum with a diameter of 400 mm.

20. The fiber of claim 19, wherein said wire mesh covered drum microbending loss is less than 0.010 dB/km at a wavelength of 1550 nm.

21. The fiber of claim 1, wherein said fiber is formed at a draw speed of at least 40 m/s.

22. An optical waveguide fiber comprising:

a central core region having a radius r₁ and a relative refractive index Δ

₁(r) in % measured relative to pure silica, said relative refractive index Δ

₁(r) having a maximum Δ

_1max;

a cladding, said cladding including an inner cladding region surrounding said central core region and an outer cladding region surrounding said inner cladding region, said inner cladding region having an outer radius r₂>

8 μ

m and a relative refractive index Δ

₂(r) in % measured relative to pure silica, said relative refractive index Δ

₂(r) having a maximum Δ

_2max and a minimum Δ

_2min, said outer cladding region having a relative refractive index Δ

₄ in % measured relative to pure silica, said relative refractive index Δ

₄ being positive and less than said maximum Δ

_1max, said relative refractive index Δ

₄ exceeding said minimum Δ

_2min by at least 0.002%;

a primary coating surrounding said outer cladding region, said primary coating having an in situ modulus of less than 0.20 MPa and an in situ glass transition temperature of less than −

35°

C.; and

a secondary coating surrounding said primary coating, said secondary coating having an in situ modulus of greater than 1500 MPa;

wherein said fiber exhibits a 2 m cutoff wavelength less than 1360 nm.

23. An optical waveguide fiber comprising:

a central core region having a radius r₁ and a relative refractive index Δ

₁(r) in % measured relative to pure silica, said relative refractive index Δ

₁(r) having a maximum Δ

_1max;

a cladding, said cladding including an inner cladding region surrounding said central core region and an outer cladding region surrounding said inner cladding region, said inner cladding region having an outer radius r₂>

8 μ

m and a relative refractive index Δ

₂(r) in % measured relative to pure silica, said relative refractive index Δ

₂(r) having a maximum Δ

_2max and a minimum Δ

_2min, said outer cladding region having a relative refractive index Δ

₄ in % measured relative to pure silica, said relative refractive index Δ

₄ being positive and less than said maximum Δ

_1max, said relative refractive index Δ

₄ exceeding said minimum Δ

_2min by at least 0.002%;

a primary coating surrounding said outer cladding region, said primary coating having an in situ modulus of less than 0.20 MPa and an in situ glass transition temperature of less than −

35°

C.; and

a secondary coating surrounding said primary coating, said secondary coating having an in situ modulus of greater than 1500 MPa;

wherein said mode field diameter is greater than 9.0 μ

m at a wavelength of 1310 nm, said 2 m cutoff wavelength is less than 1320 nm, and said wire mesh covered drum microbending loss is less than 0.020 dB/km at a wavelength of 1550 nm when wound around a mesh-covered aluminum drum with a diameter of 400 mm.