Bend-insensitive single-mode optical fiber

• US 8,131,125 B2
• Filed: 02/11/2011
• Issued: 03/06/2012
• Est. Priority Date: 05/06/2008
• Status: Active Grant

• Current Assignee: Draka Comteq BV (Prysmian SPA)
• Original Assignee: Draka Comteq BV (Prysmian SPA)
• Inventors: de Montmorillon, Louis-Anne, Richard, Simon, Molin, Denis, Boivin, David, Bigot-Astruc, Marianne, Sillard, Pierre
• Primary Examiner(s): Le, Uyen Chau N
• Assistant Examiner(s): TRAN, HOANG Q
• Application Number:
  US13/025,808
• Publication Number:
  US 20110135264A1
• Time in Patent Office: 389 Days
• Field of Search: 385/127
• US Class Current: 385/127
• CPC Class Codes: G02B 6/02266 Positive dispersion fibres at 1550 nm
• 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 6/0365 arranged - - +

Abstract

The present invention embraces a single-mode optical fiber that, at a wavelength of 1550 nanometers, has bending losses of 0.15 dB/turn or less for a radius of curvature of 5 millimeters.

Claims

1. A single-mode optical fiber, comprising:

a central core surrounded by an outer optical cladding;

wherein, at a wavelength of 1310 nanometers, the optical fiber has a nominal mode field diameter (MFD) between 8.6 microns and 9.5 microns;

wherein, at a wavelength of 1550 nanometers, the optical fiber has bending losses of 0.15 dB/turn or less for a radius of curvature of 5 millimeters; and

wherein the optical fiber has a standard cable cut-off wavelength of 1260 nanometers or less.

2. The optical fiber according to claim 1, wherein the optical fiber has (i) a zero chromatic dispersion wavelength (ZDW) between 1300 nanometers and 1324 nanometers and (ii) a zero chromatic dispersion slope value (ZDS) at the zero chromatic dispersion wavelength of 0.092 ps/(nm²·

km) or less.

3. The optical fiber according to claim 1, wherein the optical fiber has an effective cut-off wavelength λ

_ceff greater than 1300 nanometers.

4. The optical fiber according to claim 1, wherein the optical fiber has a theoretical cut-off wavelength of 1250 nanometers or less.

5. The optical fiber according to claim 1, wherein, at a wavelength of 1550 nanometers, the optical fiber has bending losses of (i) 0.003 dB/turn or less for a radius of curvature of 15 millimeters, (ii) 0.03 dB/turn or less for a radius of curvature of 10 millimeters, and (iii) 0.05 dB/turn or less for a radius of curvature of 7.5 millimeters.

6. The optical fiber according to claim 1, wherein, at a wavelength of 1625 nanometers, the optical fiber has bending losses of (i) 0.0015 dB/turn or less for a radius of curvature of 15 millimeters, (ii) 0.025 dB/turn or less for a radius of curvature of 10 millimeters, and (iii) 0.08 dB/turn or less for a radius of curvature of 7.5 millimeters.

7. The optical fiber according to claim 1, wherein, for a radius of curvature of 5 millimeters, the optical fiber has bending losses of (i) 0.10 dB/turn or less at a wavelength of 1550 nanometers and/or (ii) 0.25 dB/turn or less at a wavelength of 1625 nanometers.

8. The optical fiber according to claim 1, wherein the central core has a step-refractive index profile.

9. The optical fiber according to claim 1, comprising:

an intermediate cladding positioned between the central core and the outer optical cladding; and

a depressed trench positioned between the intermediate cladding and the outer optical cladding;

wherein the central core has a radius r₁ between about 3.8 microns and 4.35 microns and a maximum refractive index difference Δ

n₁ with the outer optical cladding between about 4.9×

10<sup>−

3</sup> and 5.7×

10<sup>−

3</sup>;

wherein the intermediate cladding has a radius r₂ between about 8.5 microns and 9.7 microns and a refractive index difference Δ

n₂ with the outer optical cladding between about −

0.1×

10<sup>−

3</sup> and 0.6×

10<sup>−

3</sup>; and

wherein the depressed trench has a radius r₃ between about 13.5 microns and 16 microns and a refractive index difference Δ

n₃ with the outer optical cladding between about −

10.0×

10<sup>−

3</sup> and −

5.0×

10<sup>−

3</sup>.

10. The optical fiber according to claim 9, wherein:

the surface integral of the central core (V₀₁), defined as

11. A buffer tube or cable containing one or more optical fibers according to claim 1.

12. A Fiber-To-The-Home (FTTH) system comprising at least a portion of the optical fiber according to claim 1.

13. A single-mode optical fiber, comprising:

a central core surrounded by an outer optical cladding;

wherein, at a wavelength of 1310 nanometers, the optical fiber has a mode field diameter (MFD) between 8.2 microns and 9.9 microns;

wherein, at a wavelength of 1550 nanometers, the optical fiber has bending losses of 0.15 dB/turn or less for a radius of curvature of 5 millimeters; and

wherein, at a wavelength of 1260 nanometers, the LP11-mode attenuation is 19.3 dB after propagation through 45 meters or less of the optical fiber while the optical fiber is straight.

14. The optical fiber according to claim 13, wherein, at a wavelength of 1260 nanometers, the LP11-mode leakage losses are 19.3 dB after propagation through 22 meters or less of the optical fiber while the optical fiber is straight.

15. The optical fiber according to claim 13, wherein the optical fiber has (i) a zero chromatic dispersion wavelength (ZDW) between 1300 nanometers and 1324 nanometers and (ii) a zero chromatic dispersion slope value (ZDS) at the zero chromatic dispersion wavelength of 0.092 ps/(nm²·

km) or less.

16. The optical fiber according to claim 13, wherein, at a wavelength of 1550 nanometers, the optical fiber has bending losses of (i) 0.00025 dB/turn or less for a radius of curvature of 15 millimeters, (ii) 0.0075 dB/turn or less for a radius of curvature of 10 millimeters, and (iii) 0.05 dB/turn or less for a radius of curvature of 7.5 millimeters.

17. The optical fiber according to claim 13, wherein, at a wavelength of 1625 nanometers, the optical fiber has bending losses of (i) 0.01 dB/turn or less for a radius of curvature of 15 millimeters, (ii) 0.1 dB/turn or less for a radius of curvature of 10 millimeters, and (iii) 0.15 dB/turn or less for a radius of curvature of 7.5 millimeters.

18. The optical fiber according to claim 13, wherein, for a radius of curvature of 5 millimeters, the optical fiber has bending losses of (i) 0.10 dB/turn or less at a wavelength of 1550 nanometers and/or (ii) 0.25 dB/turn or less at a wavelength of 1625 nanometers.

19. The optical fiber according to claim 13, comprising:

an intermediate cladding positioned between the central core and the outer optical cladding; and

a depressed trench positioned between the intermediate cladding and the outer optical cladding;

wherein the central core has a radius r₁ between about 3.8 microns and 4.05 microns and a maximum refractive index difference Δ

n₁ with the outer optical cladding between about 4.9×

10<sup>−

3</sup> and 5.7×

10<sup>−

3</sup>;

wherein the intermediate cladding has a radius r₂ between about 8.5 microns and 9.7 microns and a refractive index difference Δ

n₂ with the outer optical cladding between about −

0.1×

10<sup>−

3</sup> and 0.6×

10<sup>−

3</sup>; and

wherein the depressed trench has a radius r₃ between about 13.5 microns and 15 microns and a refractive index difference Δ

n₃ with the outer optical cladding between about −

10.0×

10<sup>−

3</sup> and −

5.0×

10<sup>−

3</sup>.

20. A buffer tube or cable containing one or more optical fibers according to claim 13.

21. An optical box receiving at least a portion of the optical fiber according to claim 13.

22. A single-mode optical fiber, comprising:

a central core surrounded by an outer optical cladding, the central core having a radius r₁ and a positive refractive index difference Δ

n₁ with the outer optical cladding;

an intermediate cladding positioned between the central core and the outer optical cladding, the intermediate cladding having a radius r₂ and a refractive index difference Δ

n₂ with the outer optical cladding, wherein the refractive index difference Δ

n₂ is less than the refractive index difference Δ

n₁; and

a depressed trench positioned between the intermediate cladding and the outer optical cladding, the depressed trench having a radius r₃ and a negative refractive index difference Δ

n₃ with the outer optical cladding;

wherein;

the surface integral of the central core (V₀₁), defined as

23. The optical fiber according to claim 22, wherein, at a wavelength of 1550 nanometers, the optical fiber has bending losses of 0.15 dB/turn or less for a radius of curvature of 5 millimeters.

24. The optical fiber according to claim 22, wherein:

the surface integral of the central core (V₀₁) is between 20.0×

10<sup>−

3</sup> micron and 21.5×

10<sup>−

3</sup> micron; and

/or

the surface integral of the depressed trench (V₀₃) is between −

42.5×

10<sup>−

3</sup> micron and −

32.5×

10<sup>−

3</sup> micron.

25. The optical fiber according to claim 22, wherein, at a wavelength of 1310 nanometers, the optical fiber has a mode field diameter (MFD) between 8.2 microns and 9.9 microns.

26. The optical fiber according to claim 22, wherein, at a wavelength of 1260 nanometers, the LP11-mode leakage losses are 19.3 dB after propagation through 30 meters or less of the optical fiber while the optical fiber is straight.

27. The optical fiber according to claim 22, wherein the optical fiber has a standard cable cut-off wavelength of 1260 nanometers or less.

28. The optical fiber according to claim 22, wherein the optical fiber has (i) a zero chromatic dispersion wavelength (ZDW) between 1300 nanometers and 1324 nanometers and (ii) a zero chromatic dispersion slope value (ZDS) at the zero chromatic dispersion wavelength of 0.092 ps/(nm²·

km) or less.

29. The optical fiber according to claim 22, wherein:

the central core has a radius r₁ between about 3.8 microns and 4.35 microns and a maximum refractive index difference Δ

n₁ with the outer optical cladding between about 4.9×

10<sup>−

3</sup> and 5.7×

10<sup>−

3</sup>;

the intermediate cladding has a radius r₂ between about 8.5 microns and 9.7 microns and a refractive index difference Δ

n₂ with the outer optical cladding between about −

0.1×

10<sup>−

3</sup> and 0.6×

10<sup>−

3</sup>; and

the depressed trench has a radius r₃ between about 13.5 microns and 16 microns and a refractive index difference Δ

n₃ with the outer optical cladding between about −

10.0×

10<sup>−

3</sup> and −

5.0×

10<sup>−

3</sup>.

30. A buffer tube or cable containing one or more optical fibers according to claim 22.