Optical fiber with reducing hydrogen sensitivity

Patent metadata

Field	Value
Publication number	US-2016009588-A1
Application number	US-201514734104-A
Country	US
Kind code	A1
Filing date	Jun 9, 2015
Priority date	Jul 9, 2014
Publication date	Jan 14, 2016
Grant date	—

Abstract

The present disclosure is directed to a method of making an optical fiber with improved bend performance, the optical fiber having a core and at least one cladding layer, and a chlorine content in the in the last layer of the at least one cladding layer that is greater than 500 ppm by weight. The fiber is prepared using a mixture of a carrier gas, a gaseous chlorine source material and a gaseous reducing agent during the sintering of the last or outermost layer of the at least one cladding layer. The inclusion of the reducing gas into a mixture of the carrier gas and gaseous chlorine material reduces oxygen-rich defects that results in at least a 20% reduction in TTP during hydrogen aging testing.

First claim

We claim:

1 . A method of producing an optical fiber comprising:
providing a preform having a consolidated glass core and a first porous glass cladding layer; exposing the preform to a first gas atmosphere at a first temperature, the first gas atmosphere comprising a chlorine source material, the chlorine source material providing chlorine for doping the first porous glass cladding layer; exposing the preform to a second gas atmosphere at a second temperature; the second gas atmosphere comprising a reducing agent; and heating the preform in the presence of the second gas atmosphere at a third temperature; the heating causing sintering of the first porous glass cladding layer, the sintered first porous glass cladding layer having a chlorine dopant concentration of at least 500 ppm by weight.

2 . The method of claim 1 , wherein the first temperature is at least 800° C., the second temperature is greater than or equal to the first temperature, and the third temperature is greater than or equal to the second temperature.

3 . The method of claim 2 , wherein the first temperature is at least 1050° C. and the third temperature is at least 1300° C.

4 . The method of claim 1 , wherein the chlorine source material is Cl 2 , SiCl 4 , or CCl 4 and wherein the reducing agent is CO, CH 3 Cl, CH 2 Cl 2 , or CHCl 3 .

5 . The method of claim 1 , wherein the chlorine source material comprises Cl 2 and the reducing agent comprises CO.

6 . The method of claim 1 , wherein the second gas atmosphere does not contain chlorine.

7 . The method of claim 1 , wherein the reducing agent is CO and the concentration of CO in the second gas atmosphere is greater than 1000 ppm by volume.

8 . The method of claim 1 , wherein the reducing agent is CO and the concentration of CO in the second gas atmosphere is greater than 5000 ppm by volume.

9 . The method of claim 1 , wherein the second gas atmosphere comprises the first gas atmosphere.

10 . The method of claim 9 , wherein the volumetric ratio of the reducing agent to the chlorine source material in the second gas atmosphere is greater than 0.005.

11 . The method of claim 9 , wherein the volumetric ratio of the reducing agent to the chlorine source material in the second gas atmosphere is greater than 0.020.

12 . The method of claim 1 , wherein the reducing agent is CO and the ratio of the concentration of CO in the second gas atmosphere in units of ppm by volume to the chlorine dopant concentration in the sintered first porous glass cladding layer in units of ppm by weight is greater than 0.5.

13 . The method of claim 1 , wherein the reducing agent is CO and the ratio of the concentration of CO in the second gas atmosphere in units of ppm by volume to the chlorine dopant concentration in the sintered first porous glass cladding layer in units of ppm by weight is greater than 2.0.

14 . The method of claim 1 , wherein the chlorine dopant concentration in the sintered first porous glass cladding layer is greater than 2000 ppm by weight.

15 . The method of claim 1 , wherein the preform further comprises a second porous glass cladding layer, the second porous glass cladding layer surrounding the first porous glass cladding layer.

16 . The method of claim 15 , wherein
the chlorine source material further provides chlorine for doping the second porous glass cladding layer and the heating at the third temperature causes sintering of the second porous glass cladding layer, the chlorine dopant concentration of the sintered first porous glass cladding layer being at least 1000 ppm by weight and the sintered second porous glass cladding layer having a chlorine dopant concentration less than said chlorine dopant concentration of the sintered first porous glass cladding layer.

17 . The method of claim 1 , further comprising drawing a fiber from the preform with sintered first porous glass cladding layer.

18 . An optical fiber comprising a core and at least one cladding layer, the at least one cladding layer including a chlorine dopant concentration of at least 500 ppm by weight, the optical fiber containing less than 1 ppb by weight of OD groups and having a time-to-peak (TTP) hydrogen aging value at 23° C. of less than 100 hours upon exposure to a gas atmosphere having a total pressure of 1 atm and containing a partial pressure of 0.01 atm H 2 and a partial pressure of 0.99 atm N 2 .

19 . The optical fiber of claim 18 , wherein the time-to-peak (TTP) hydrogen aging value is less than 60 hours.

20 . The optical fiber of claim 18 , wherein the at least one cladding layer includes a chlorine dopant concentration of at least 2000 ppm by weight.

Assignees

• Corning Inc

Inventors

• Bookbinder Dana Craig
• Desorcie Robert Brett
• Matthews Iii Hazel Benton
• Tandon Pushkar

Classifications

• C03B2201/20

  doped with non-metals other than boron or fluorine · CPC title

• C03B2201/31

  doped with germanium · CPC title

• G02B6/03627

  arranged - + · CPC title

• C03B37/01446 Primary

  Thermal after-treatment of preforms, e.g. dehydrating, consolidating, sintering (C03B37/01853 takes precedence) · CPC title

• G02B6/02

  Optical fibres with cladding {with or without a coating} · CPC title