Optical fiber and method for making such fiber

• US 7,313,312 B2
• Filed: 02/11/2005
• Issued: 12/25/2007
• Est. Priority Date: 02/20/2004
• Status: Expired

• Current Assignee: Corning Incorporated
• Original Assignee: Corning Incorporated
• Inventors: Wang, Ji, Kimball, Ronald L., Zenteno, Luis A., Walton, Donnell T., Knowlton, Robert A, McCarthy, Joseph E
• Primary Examiner(s): Font; Frank G.
• Assistant Examiner(s): Mooney; Michael P.
• Application Number:
  US11/056,870
• Publication Number:
  US 20050271347A1
• Time in Patent Office: 1,047 Days
• Field of Search: 385/123, 385/127, 385/141, 385/142
• US Class Current: 385/142
• CPC Class Codes: C03B 2201/10 doped with boron C03B2201/14 takes precedence
• CPC Class Codes: C03B 2201/12 doped with fluorine C03B2201/14 takes precedence
• CPC Class Codes: C03B 2201/14 doped with boron and fluorine
• CPC Class Codes: C03B 2201/28 doped with phosphorus
• CPC Class Codes: C03B 2201/31 doped with germanium
• CPC Class Codes: C03B 2201/32 doped with aluminium C03B2201/36 takes precedence
• CPC Class Codes: C03B 2201/34 doped with rare earth metals, i.e. with Sc, Y or lanthanides, e.g. for laser-amplifiers
• CPC Class Codes: C03B 2201/36 doped with rare earth metals and aluminium, e.g. Er-Al co-doped
• CPC Class Codes: C03B 2203/04 Polygonal outer cross-section, e.g. triangular, square
• CPC Class Codes: C03B 2203/10 Internal structure or shape details
• CPC Class Codes: C03B 2203/23 Double or multiple optical cladding profiles
• CPC Class Codes: C03B 2203/30 Polarisation maintaining [PM], i.e. birefringent products, e.g. with elliptical core, by use of stress rods, "PANDA" type fibres
• CPC Class Codes: C03B 2207/85 with vapour generated from liquid glass precursors, e.g. directly by heating the liquid
• CPC Class Codes: C03B 2207/90 with vapour generated from solid glass precursors, i.e. by sublimation
• CPC Class Codes: C03B 37/01413 Reactant delivery systems C03B37/01807 takes precedence; devices therefor in general B01D1/00, B01J4/00
• CPC Class Codes: C03C 13/046 Multicomponent glass compositions
• CPC Class Codes: G02B 6/024 with polarisation maintaining properties
• CPC Class Codes: G02B 6/03611 Highest index adjacent to central axis region, e.g. annular core, coaxial ring, centreline depression affecting waveguiding
• CPC Class Codes: G02B 6/0365 arranged - - +
• CPC Class Codes: G02B 6/03694 Multiple layers differing in properties other than the refractive index, e.g. attenuation, diffusion, stress properties
• CPC Class Codes: H01S 3/06716 : Fibre compositions per se C03C13/04or doping with active elements lasing materials in general H01S3/14
• CPC Class Codes: H01S 3/1618 : ytterbium

Abstract

According to one example of the invention an optical fiber comprises: (i) silica based, rare earth doped core having a first index of refraction n₁; (ii) at least one silica based cladding surrounding the core and having a second index of refraction n₂, such that n₁>n₂; wherein at least one of the core or cladding is doped with Al₂O₃, such that the ratio of max wt % to min wt % of Al₂O₃ concentration is less than 2:1.

Claims

1. An optical fiber comprising:

(i) a silica based, rare earth doped core having a first index of refraction n₁;

(ii) at least one silica based cladding surrounding the core and having a second index of refraction n₂, such that n₁>

n₂;

wherein at least one of the core or cladding is doped with Al₂O₃, such that the ratio of max wt % to min wt % of Al₂O₃ concentration in said core or cladding is less than 1.5;

1.

2. The optical fiber according to claim 1 wherein Al₂O₃ dopant is the core.

3. The optical fiber according to claim 2 wherein said ratio is less than 1.2:

1.

4. The optical fiber according to claim 2 wherein said ratio less than 1.1:

1.

5. The optical fiber according to claim 2 wherein said fiber core includes rare earth dopant(s).

6. The optical fiber as in any one of claims 1-5 wherein maximum Al₂O₃ concentration is over 3 wt %.

7. The optical fiber of claim 6 wherein said optical fiber includes an inner cladding and an outer cladding surrounding the inner cladding.

8. The optical fiber according to claims 1 wherein said fiber is manufactured by the outside vapor deposition process.

9. The optical fiber according to claims 8 wherein AlCl₃ is delivered to a burner with heated Helium gas.

17. The optical fiber according to claim 1, wherein the core background loss of said fiber is less than 5 dB/km at a wavelength of 1280 nm.

18. The optical fiber according to claim 17 wherein the core background loss of said fiber is less than 3 dB/km at a wavelength of 1280 nm.

19. The optical fiber according to claim 1 wherein said fiber includes an inner cladding surrounding said core, an outer cladding layer surrounding said inner cladding layer.

20. The optical fiber according to claim 19 wherein said dopant is Yb or Er.

10. An optical fiber comprising:

(i) a silica based, rare earth doped core having a first index of refraction n₁;

(ii) at least one silica based layer surrounding the core and having a second index of refraction n₂, such that n₁>

n₂;

wherein said layer includes in weight percent;

11. The optical fiber according to claim 10, wherein the amount of Boron and Fluorine is as follows:

12. The optical fiber according to claim 10, wherein the amount of Boron and Fluorine is as follows:

13. The optical fiber according to claim 10, wherein the amount of Boron is at least 8 wt % and the amount of Fluorine is at least 2 wt %.

14. The optical fiber as in any one of claims 10-12, wherein said layer is a cladding layer.

15. The optical fiber according to claim 14, wherein said optical fiber has an inner cladding layer and an outer cladding layer, and said cladding layer doped with Boron and Fluorine is the outer cladding layer.

16. An optical fiber comprising:

silica based, rare earth doped core having a first index of refraction n₁;

at least one silica based layer surrounding the core and having a second index of refraction n₂, such that n₁>

n₂;

wherein said layer includes in weight percent;

Boron—

at least 8 wt %, and Fluorine—

at least 2 wt %.