Method of making updoped cladding by using silicon tertrachloride as the dopant

Patent metadata

Field	Value
Publication number	US-9290405-B2
Application number	US-201414467369-A
Country	US
Kind code	B2
Filing date	Aug 25, 2014
Priority date	Sep 6, 2013
Publication date	Mar 22, 2016
Grant date	Mar 22, 2016

Abstract

One embodiment of the disclosure relates to a method of making an optical fiber comprising the steps of: (i) exposing a silica based preform with at least one porous glass region having soot density of ρ to a gas mixture comprising SiCl 4 having SiCl 4 mole fraction y SiCl4 at a doping temperature T dop such that parameter X is larger than 0.03 to form the chlorine treated preform, wherein
X = 1 1 + [ ( ρ ρ s - ρ ) ⁢ 0.209748 ⁢ T dop ⁢ Exp ⁡ [ - 5435.33 / T dop ] y SiCl ⁢ ⁢ 4 3 / 4 ]
and ρ s is the density of the fully densified soot layer; and (ii) exposing the chlorine treated preform to temperatures above 1400° C. to completely sinter the preform to produce sintered optical fiber preform with a chlorine doped region; and (iii) drawing an optical fiber from the sintered optical preform.

First claim

What is claimed is:

1. A method of making an optical fiber preform comprising the steps of:
(i) exposing a silica based preform with at least one porous glass region of silica based soot with soot density of ρ at a doping temperature T dop to a gas mixture comprising SiCl 4 and having SiCl 4 mole fraction y SiCl4 such that parameter X is larger than 0.03 to form a chlorine (Cl) treated preform with Cl doped region, wherein

X
=

1

1
+

[

(

ρ

ρ
s

-
ρ

)

⁢

0.21
⁢

T
dop

⁢

Exp
⁡

[

-
5435.33

/

T
dop

]

y

SiCl
⁢

⁢
4

3
/
4

]

ρ s is the density of the fully densified soot layer and ρ<ρ s ; and
(ii) exposing the chlorine treated preform to temperatures above 1400° C. to completely sinter the chlorine treated preform and producing a sintered optical fiber preform with a chlorine doped region having a chlorine doped profile, wherein the SiCl 4 mole fraction y SiCl4 is less than 0.03.

2. The method of making an optical fiber preform according to claim 1 , wherein the parameter X is larger than 0.04.

3. The method of making an optical fiber preform according to claim 1 , wherein chlorine doping profile of the Cl doped region is such that the ratio of the concentration of doped chlorine in an inner portion of the Cl doped region to maximum concentration of doped chlorine in the Cl doped region is ≧0.4.

4. The method of making an optical fiber preform according to claim 1 , wherein chlorine doping profile is such that the ratio of the concentration of doped chlorine in the inner portion of the Cl doped region to concentration of doped chlorine in the outer portion of the Cl doped region is ≧0.75.

5. The method of making an optical fiber preform according to claim 1 , wherein T dop is less than 1225° C.

6. The method of making an optical fiber preform according to claim 1 , wherein T dop is less than 1200° C.

7. The method of making an optical fiber preform according to claim 1 , wherein the mole fraction of SiCl 4 in the gas mixture y SiCl4 is larger than 0.005.

8. The method of making an optical fiber preform according to claim 1 , wherein the mole fraction of SiCl 4 in the gas mixture y SiCl4 is larger than 0.015.

9. A method of making an optical fiber preform comprising the steps of:
(i) exposing a silica based preform with at least one porous glass region having soot density of ρ to a gas mixture comprising SiCl 4 having SiCl 4 mole fraction y SiCl4 at a doping temperature T dop such that parameter X is larger than 0.03 to form the chlorine (Cl) treated preform with Cl doped region, wherein

X
=

1

1
+

[

(

ρ

ρ
s

-
ρ

)

⁢

0.21
⁢

T
dop

⁢

Exp
⁡

[

-
5435.33

/

T
dop

]

y

SiCl
⁢

⁢
4

3
/
4

]

and ρ s is the density of the fully densified soot layer, and at least a portion of the inside of the soot layer is at a temperature T inside that is at least 25° C. higher than the doping temperature T dop ;
(ii) exposing the chlorine treated preform to temperatures above 1400° C. to completely sinter the preform to produce sintered optical fiber preform with a chlorine doped region having a chlorine doped profile.

10. The method of making an optical fiber preform according to claim 9 , wherein the difference between T inside and T dop is less than 80° C.

11. The method of making an optical fiber preform according to claim 9 , wherein paramete

Assignees

• Corning Inc

Inventors

• Harper Brian Lee
• Khrapko Rostislav Radiyevich
• Mishra Snigdharaj Kumar
• Raney Sonya Marie
• Tandon Pushkar

Classifications

• C03B2201/20

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

• C03C2201/20

  containing non-metals other than boron or halide · CPC title

• C03C2201/11

  containing chlorine · CPC title

• C03B37/014

  made entirely or partially by chemical means {, e.g. vapour phase deposition of bulk porous glass either by outside vapour deposition [OVD], or by outside vapour phase oxidation [OVPO] or by vapour axial deposition [VAD] (C03C17/02 takes precedence)} · CPC title

• C03B2203/26

  Parabolic or graded index [GRIN] core profile · CPC title