Method for fabricating optical fiber preform and method for fabricating optical fiber using the same

Abstract

Disclosed are a method for fabricating an optical fiber preform and a method for fabricating an optical fiber using the optical fiber preform. The method for fabricating the optical fiber preform including the steps of: (a) growing a first soot preform on a starting member by a soot deposition; (b) dehydrating the first soot preform; (c) sintering the first dehydrated soot preform to obtain a first glassed optical fiber perform; (e) growing an over-clad soot layer on the first optical fiber preform by soot deposition to obtain a second soot preform; and (f) sintering the second soot preform so as to obtain a second optical fiber preform which is glassed, wherein an average density of the first soot preform is substantially within a range of 0.19˜0.30 g/cc, and the average density of the over-clad soot layer is substantially within a range of 0.5˜0.75 g/cc.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be more apparent from the following detailed description taken in conjunction with the accompanying drawings, in which:

FIG. 1 is a flowchart illustrating a method for fabricating an optical fiber preform according to a preferred embodiment of the present invention;

FIG. 2 is a view illustrating a step for growing a first soot preform;

FIG. 3 is a view illustrating a step for dehydrating the first soot preform;

FIG. 4 is a view illustrating a step for sintering the first dehydrated soot preform;

FIG. 5 is a view illustrating a step for elongating the first optical fiber preform;

FIG. 6 is a view illustrating a step for growing an over-clad soot layer;

FIG. 7 is a view illustrating a step for sintering a second soot preform;

FIG. 8 is a view illustrating steps for drawing an optical fiber;

FIG. 9 is a graph illustrating a breakage frequency of the first optical fiber preform and a loss of the optical fiber depending on an average density of the first soot preform;

FIG. 10 is a graph illustrating a breakage frequency and an exterior crack of the second optical fiber preform depending on an average density of an over-clad layer; and

FIG. 11 is a graph illustrating a spectrum loss of an optical fiber drawn from the second optical fiber preform satisfying an optimal average density condition.

Claims

1. A method for fabricating an optical fiber preform, the method comprising the steps of: (a) growing a first soot preform on a starting member by a soot deposition;(b) dehydrating the first soot preform; and(c) sintering the first dehydrated soot preform to obtain a first glassed optical fiber perform,wherein an average density of the first soot preform is substantially within a range of 0.19˜0.30 g/cc.

2. The method as claimed in claim 1, further comprising the steps of: (e) growing an over-clad soot layer on the first optical fiber preform by the soot deposition to obtain a second soot preform; and(f) sintering the second soot preform to obtain a second optical fiber preform that is glassed.

3. The method as claimed in claim 2, wherein the average density of the over-clad soot layer is substantially within a range of 0.5˜0.75 g/cc.

4. The method as claimed in claim 2, further comprising a step of (d) elongating the first optical fiber perform between step (c) and step (e), wherein the step (e) is performed with relation to the first elongated optical fiber preform.

5. The method as claimed in claim 1, wherein the average density of the first soot preform is substantially within a range of 0.20˜0.26 g/cc.

6. A method for fabricating an optical fiber preform, comprising the steps of: (a) growing a first soot preform on a starting member by a soot deposition;(b) dehydrating the first soot preform;(c) sintering the first dehydrated soot preform to obtain a first glassed optical fiber perform;(e) growing an over-clad soot layer on the first optical fiber preform by the soot deposition to obtain a second soot preform; and(f) sintering the second soot preform so as to obtain a second optical fiber preform that is glassed,wherein an average density of the first soot preform is substantially within a range of 0.19˜0.30 g/cc, and the average density of the over-clad soot layer is substantially within a range of 0.5˜0.75 g/cc.

7. The method as claimed in claim 6, wherein the average density of the first soot preform is substantially within a range of 0.20˜0.26 g/cc.

8. The method as claimed in claim 6, further comprising a step of (d) elongating the first optical fiber perform between step (c) and step (e), wherein the step (e) is performed with relation to the first elongated optical fiber preform.

9. A method for fabricating an optical fiber, the method comprising the steps of: (a) growing a first soot preform on a starting member by a soot deposition;(b) dehydrating the first soot preform;(c) sintering the first dehydrated soot preform to obtain a first glassed optical fiber perform;(e) growing an over-clad soot layer on the first optical fiber preform by soot deposition to obtain a second soot preform;(f) sintering the second soot preform to obtain a second optical fiber preform which is glassed; and(g) heating and melting an end portion of the second optical fiber preform while drawing an optical fiber,wherein an average density of the first soot preform is substantially within a range of 0.19˜0.30 g/cc, and the average density of the over-clad soot layer is substantially within a range of 0.5˜0.75 g/cc.

10. The method as claimed in claim 9, wherein the average density of the first soot preform is substantially within a range of 0.20˜0.26 g/cc.

11. The method as claimed in claim 6, further comprising a step of (d) elongating the first optical fiber perform between step (c) and step (e), wherein the step (e) is performed with relation to the first elongated optical fiber preform.