Large effective area fiber

• US 7,555,187 B2
• Filed: 05/05/2008
• Issued: 06/30/2009
• Est. Priority Date: 05/07/2007
• Status: Active Grant

• Current Assignee: Corning Incorporated
• Original Assignee: Corning Incorporated
• Inventors: Li, Ming-Jun, Bookbinder, Dana Craig, Chen, Xin, Mishra, Snigdharaj Kumar, Bickham, Scott Robertson, Nolan, Daniel Aloysius
• Primary Examiner(s): STAHL, MICHAEL J
• Application Number:
  US12/151,171
• Publication Number:
  US 20080279517A1
• Time in Patent Office: 421 Days
• Field of Search: None
• US Class Current: 385/127
• CPC Class Codes: G02B 6/02019 Effective area greater than 90 square microns in the C band, i.e. 1530-1565 nm
• CPC Class Codes: G02B 6/0365 arranged - - +

Abstract

An optical fiber according to an embodiment of the present invention comprises: a glass core extending from a centerline to a radius R₁ wherein R₁ is greater than about 5 μm; a glass cladding surrounding and in contact with the core, the cladding comprising: (i) a first annular region extending from the radius R₁ to a radius R₂, the first annular region comprising a radial width, W₂=R₂−R₁, (ii) a second annular region extending from the radius R₂ to a radius R₃, and comprising a radial width, W₃=R₃−R₂, and (iii) a third annular region surrounding the second annular region and extending from the radius R₃ to an outermost glass radius R₄; wherein the core comprises a maximum relative refractive index, Δ_1MAX, relative to the third annular region, and wherein Δ_1MAX is greater than about 0.1% and less than about 0.3%; the first annular region has a refractive index delta Δ₂(r) is less than about 0.025%; wherein the second annular region comprises a minimum relative refractive index, Δ_3MIN, relative to the third annular region;

wherein Δ_1MAX>Δ_2MAX>Δ_3MIN, and Δ_2MIN>Δ_3MIN<0; and

wherein the core and the cladding provide a fiber with cable cutoff less than 1500 nm, and an effective area at 1550 nm greater than 95 μm² and bend loss of ≦0.5 dB/turn on a 20 mm diameter mandrel.

Claims

1. An optical fiber comprising:

a glass core extending from a centerline to a radius R₁ wherein R₁ is greater than about 5 μ

m;

a glass cladding surrounding and in contact with the core,

wherein the core and the cladding provide a fiber with cable cutoff less than 1500 nm, and an effective area at 1550 nm greater than 110 μ

m² and bend loss of ≦

0.7 dB/turn on a 20 mm diameter mandrel and, wherein

(i) the cladding comprises;

a first annular region extending from the radius R₁ to a radius R₂, the first annular region comprising a radial width, W₂=R₂−

R₁,

a second annular region extending from the radius R₂ to a radius R₃, and comprising a radial width, W₃=R₃−

R₂, and

a third annular region surrounding the second annular region and extending from the radius R₃ to an outermost glass radius R₄; and

(ii) the core comprises a maximum relative refractive index, Δ

_1MAX, relative to the third annular region;

wherein the first annular region has a refractive index delta Δ

₂(r);

wherein the second annular region comprises;

a minimum relative refractive index, Δ

_3MIN, relative to the third annular region;

wherein Δ

_1MAX>

Δ

_2MAX>

Δ

_3MIN, Δ

_2MIN>

Δ

_3MIN, and Δ

₃MIN<

0 wherein Δ

_1MAX is greater than about 0.1% and less than about 0.3%; and

Δ

₂(r), is less than about 0.025%, and wherein Δ

_3MIN, relative to the third annular region, is less than about −

0.1%.

2. The optical fiber of claim 1, wherein Δ

_3MIN, relative to the third annular region, is less than about −

0.3%.

3. The optical fiber of claim 1 wherein the second annular region comprises a profile volume, V₃, equal to:

$2<br><br>{\int <br><br>}_{R_2}^{R_3}<br><br>\mathrm{\Delta <br><br>}<br><br>\left(r\right)<br><br>r<br><br><br><br>d<br><br>r;<br><br>$

wherein |V₃| is at least 20%-μ

m².

6. The optical fiber of claim 2, wherein the core in combination with the cladding provide a bend loss at 1550 nm wavelength of less than 0.25 dB/turn on a 20 mm diameter mandrel.

7. The optical fiber of claim 2, wherein the core in combination with the cladding provide a bend loss at 1550 nm wavelength of less than 0.10 dB/turn on a 20 mm diameter mandrel.

8. The optical fiber of claim 3 wherein 20%-μ

m²<

|V₃|<

80%-μ

m².

9. The optical fiber of claim 2, wherein R₂>

10 μ

m.

13. The optical fiber of claim 2, wherein R₁/R₂ is between about 0.3 and 0.4.

4. An optical fiber comprising:

a glass core extending from a centerline to a radius R₁ wherein R₁ is greater than about 5 μ

m;

a glass cladding surrounding and in contact with the core,

wherein the core and the cladding provide a fiber with cable cutoff less than 1500 nm, and an effective area at 1550 nm greater than 110 μ

m² and bend loss of ≦

0.7 dB/turn on a 20 mm diameter mandrel and, wherein

(i) the cladding comprises;

a first annular region extending from the radius R₁ to a radius R₂, the first annular region comprising a radial width, W₂=R₂−

R₁,

a second annular region extending from the radius R₂ to a radius R₃, and comprising a radial width, W₃=R₃−

R₂, and

a third annular region surrounding the second annular region and extending from the radius R₃ to an outermost glass radius R₄; and

(ii) the core comprises a maximum relative refractive index, Δ

_1MAX, relative to the third annular region;

wherein the first annular region has a refractive index delta Δ

₂(r);

wherein the second annular region comprises;

a minimum relative refractive index, Δ

_3MIN, relative to the third annular region;

wherein Δ

_1MAX>

Δ

_2MAX>

Δ

_3MIN, Δ

_2MIN>

Δ

_3MIN, and Δ

_3MIN<

0, wherein said second annular region comprises silica based glass with a plurality of closed randomly dispersed holes situated therein.

5. The optical fiber of claim 4, wherein said second annular region comprises silica based glass with at least 50 closed randomly dispersed holes situated therein, and (i) mean distance between the holes is less than 5000 nm, and (ii) at least 80% of the holes have a maximum cross-sectional dimension Di of less than 1000 nm.

26. The optical fiber of claim 4, wherein said effective area at 1550 nm is greater than 125 μ

m².

10. An optical fiber comprising:

a glass core extending from a centerline to a radius R₁ wherein R₁ is greater than about 5 μ

m;

a glass cladding surrounding and in contact with the core,

wherein the core and the cladding provide a fiber with cable cutoff less than 1500 nm, and an effective area at 1550 nm greater than 110 μ

m² and bend loss of ≦

0.7 dB/turn on a 20 mm diameter mandrel and, wherein

(i) the cladding comprises;

a first annular region extending from the radius R₁ to a radius R₂, the first annular region comprising a radial width, W₂=R₂−

R₁,

a second annular region extending from the radius R₂ to a radius R₃, and comprising a radial width, W₃=R₃−

R₂, and

a third annular region surrounding the second annular region and extending from the radius R₃ to an outermost glass radius R₄; and

(ii) the core comprises a maximum relative refractive index, Δ

_1MAX, relative to the third annular region;

wherein the first annular region has a refractive index delta Δ

₂(r);

wherein the second annular region comprises;

a minimum relative refractive index, Δ

_3MIN, relative to the third annular region;

wherein Δ

_1MAX>

Δ

_2MAX>

Δ

_3MIN, Δ

_2MIN>

Δ

_3MIN, and Δ

_3MIN<

0, wherein said effective area is at least 125 μ

m².

11. The optical fiber of claim 10 wherein said effective area is at least 135 μ

m².

12. An optical fiber comprising:

a glass core extending from a centerline to a radius R₁ wherein R₁ is greater than about 5 μ

m;

a glass cladding surrounding and in contact with the core,

wherein the core and the cladding provide a fiber with cable cutoff less than 1500 nm, and an effective area at 1550 nm greater than 110 μ

m² and bend loss of ≦

0.7 dB/turn on a 20 mm diameter mandrel and, wherein

(i) the cladding comprises;

a first annular region extending from the radius R₁ to a radius R₂, the first annular region comprising a radial width, W₂=R₂−

R₁.

a second annular region extending from the radius R₂ to a radius R₃, and comprising a radial width, W₃=R₃−

R₂, and

a third annular region surrounding the second annular region and extending from the radius R₃ to an outermost glass radius R₄; and

(ii) the core comprises a maximum relative refractive index, Δ

_1MAX, relative to the third annular region;

wherein the first annular region has a refractive index delta Δ

₂(r);

wherein the second annular region comprises;

a minimum relative refractive index, Δ

_3MIN, relative to the third annular region;

wherein Δ

_1MAX>

Δ

_2MAX>

Δ

_3MIN, Δ

_2MIN>

Δ

_3MIN, and Δ

_3MIN<

0, wherein Δ

_1MAX is greater than about 0.1% and less than about 0.3%; and

Δ

₂(r), is less than about 0.025%, and wherein W₃ is between 1 μ

m and 10 μ

m.

14. An optical fiber comprising:

a glass core extending from a centerline to a radius R₁ wherein R₁ is greater than about 5 μ

m;

a glass cladding surrounding and in contact with the core, the cladding comprising;

a first annular region extending from R₁ to a radius R₂, the first annular region comprising a radial width, W₂=R₂−

R₁.

a second annular region extending from R₂ to a radius R₃, and comprising a radial width, W₃=R₃−

R₂, and

a third annular region surrounding the second annular region and extending from the radius R₃ to an outermost glass radius R₄;

wherein the core comprises a maximum relative refractive index, Δ

_1MAX, relative to the third annular region, and wherein Δ

_1MAX is greater than about 0.1% and less than about 0.3%;

wherein the first annular region has a refractive index delta Δ

₂(r) is less than about 0.025%;

wherein the second annular region comprises;

a minimum relative refractive index, Δ

_3MIN, relative to the third annular region;

wherein Δ

_1MAX>

Δ

_2MAX>

Δ

_3MIN, Δ

_2MIN>

Δ

_3MIN and Δ

_3MIN<

0, and includes silica based glass with at least 10 randomly dispersed closed holes situated therein, and (i) mean distance between the holes is less than 5000 nm, and (ii) at least 80% of the holes have a maximum cross-sectional dimension Di of less than 1000 nm; and

wherein the core and the cladding provide a fiber with cable cutoff less than 1500 nm, and an effective area at 1550 nm greater than 95 μ

m² and bend loss of no more than 0.5 dB/turn on a 20 mm diameter mandrel.

15. The optical fiber of claim 14 wherein said second annular region includes at least 50 randomly dispersed closed holes situated therein.

16. The opticai fiber of claim 14 wherein R₂>

12 μ

m and W₃ is 2 μ

m to 10 μ

m.

17. The optical fiber of claim 14 wherein the core and the cladding provide a fiber with cable cutoff less than 1450 nm.

18. The optical fiber of claim 14 wherein the bend loss of said fiber is less than 0.25 dB/turn at 20 mm bending diameter and less than 0.01 dB/turn at 30 mm bending diameter.

19. An optical fiber comprising:

a glass core extending from a centerline to a radius R₁ wherein R₁ is greater than about 5 μ

m;

a glass cladding surrounding and in contact with the core, the cladding comprising;

a first annular region extending from R₁ to a radius R₂, the first annular region comprising a radial width, W₂=R₂−

R₁,

a second annular region extending from R₂ to a radius R₃, and comprising a radial width, W₃=R₃−

R₂, and

a third annular region surrounding the second annular region and extending from the radius R₃ to an outermost glass radius R₄;

wherein the core comprises a maximum relative refractive index, Δ

_1MAX, relative to the third annular region, and wherein Δ

_1MAX is greater than about 0.1% and less than about 0.3%;

wherein the first annular region has a refractive index delta Δ

₂(r) is less than about 0.025% and larger than about −

0.025%;

wherein the second annular region comprises;

a minimum relative refractive index, Δ

_3MIN, relative to the third annular region;

wherein Δ

_1MAX>

Δ

_2MAX>

Δ

_3MIN, and Δ

_2MIN>

Δ

_3MIN and Δ

_3MIN<

−

0.1%, and

wherein the core and the cladding provide a fiber with cable cutoff less than 1500 nm, and an effective area at 1550 nm greater than 95 μ

m² and bend loss of no more than 0.7 dB/turn on a 20 mm diameter mandrel.

20. The optical fiber of claim 19 wherein said second annular region comprises at least one of:

i) fluorine;

ii) closed randomly dispersed holes.

21. The optical fiber of claim 19 wherein said fiber has a dispersion of 21 ps/nm/km or less at a wavelength of 1550 nm.

22. The optical fiber of claim 19 wherein said fiber has Δ

_1MAX of greater than 0.17% and less than 0.28%.

23. The optical fiber of claim 19, wherein said effective area at 1550 nm is greater than 125 μ

m².

24. The optical fiber of claim 23 wherein said effective area at 1550 nm is not greater than 167 μ

m².

25. The optical fiber of claim 19, wherein the ratio of the R₁ to the radius R₂ is:

0.2<

R₁/R₂<

0.4.