Production method of optical fiber preform and production method of optical fiber

Patent metadata

Field	Value
Publication number	US-2016347645-A1
Application number	US-201615231896-A
Country	US
Kind code	A1
Filing date	Aug 9, 2016
Priority date	Mar 6, 2014
Publication date	Dec 1, 2016
Grant date	—

Abstract

A production method of an optical fiber preform includes: preparing a plurality of bar-shaped first preforms and a plurality of second preforms including through holes having substantially same shape with a shape of outer periphery of a cross section of the first preform, the cross section being orthogonal to a major axis of the first preform; and an assembly step of: matching the through holes of the second preforms to make communication holes; and inserting, through each of the communication holes, at least two of the first preforms arranged side by side in a direction of the major axis such that the second preforms and the first preforms are fitting each other. In at least one position in the direction of the major axis of the communication holes, a position where the second preforms contact with each other differs from a position where the first preforms contact with each other.

First claim

What is claimed is:

1 . A production method of an optical fiber preform, comprising:
a preparatory step of preparing: a plurality of bar-shaped first preforms; and a plurality of second preforms including through holes having substantially same shape with a shape of outer periphery of a cross section of the first preform, the cross section being orthogonal to a major axis of the first preform; and an assembly step of:
matching the through holes of the second preforms to make communication holes; and
inserting, through each of the communication holes, at least two of the first preforms arranged side by side in a direction of the major axis such that the second preforms and the first preforms are fitting each other,
wherein in at least one position in the direction of the major axis of the communication holes, a position where the second preforms contact with each other differs from a position where the first preforms contact with each other.

2 . The production method of the optical fiber preform according to claim 1 , wherein
the first preform is a core preform including:
a core portion; and
a cladding portion formed on an outer periphery of the core portion and having lower refractive index than the core portion, and
the second preform is a cladding preform having lower refractive index than the core portion.

3 . The production method of the optical fiber preform according to claim 1 , wherein a length of the through holes of the second preforms in an extending direction is equal to or less than 35 times a diameter of the through hole.

4 . The production method of the optical fiber preform according to claim 1 , further comprising
an integrating step of heating and integrating a preform formed at the assembly step.

5 . The production method of the optical fiber preform according to claim 1 , wherein a clearance between the first preform and the through hole is equal to or less than 0.7 mm.

6 . A production method of an optical fiber comprising:
producing an optical fiber preform by a production method including:
a preparatory step of preparing: a plurality of bar-shaped first preforms; and a plurality of second preforms including through holes having substantially same shape with a shape of outer periphery of a cross section of the first preform, the cross section being orthogonal to a major axis of the first preform; and
an assembly step of:
matching the through holes of the second preforms to make communication holes; and
inserting, through each of the communication holes, at least two of the first preforms arranged side by side in a direction of the major axis such that the second preforms and the first preforms are fitting each other,

wherein in at least one position in the direction of the major axis of the communication holes, a position where the second preforms contact with each other differs from a position where the first preforms contact with each other; and
heating, fusing and drawing the optical fiber preform.

7 . The production method of the optical fiber according to claim 6 , wherein
the first preform is a core preform including:
a core portion; and
a cladding portion formed on an outer periphery of the core portion and having lower refractive index than the core portion, and
the second preform is a cladding preform having lower refractive index than the core portion.

8 . The production method of the optical fiber according to claim 6 , wherein a length of the through holes of the second preforms in an extending direction is equal to or less than 35 times a diameter of the through hole.

9 . The production method of the optical fiber according to claim 6 , further comprising
an integrating step of heating and integrating a preform formed at the assembly step.

10 . The production method of the optical fiber according to claim 6 , wherein a clearance between the first preform and the through hole is equal to or less than 0.7 mm.

Assignees

• Furukawa Electric Co Ltd

Inventors

• Gonda Tomohiro
• Miyabe Ryo
• Imamura Katsunori
• Saito Tsunetoshi
• Sugizaki Ryuichi

Classifications

• C03B37/01222 Primary

  for making preforms of multiple core optical fibres (preforms of multifibres C03B37/01214) · CPC title

• G02B6/02042

  Multicore optical fibres · CPC title

• C03B2203/23

  Double or multiple optical cladding profiles · CPC title

• C03B37/025

  from reheated softened tubes, rods, fibres or filaments {, e.g. drawing fibres from preforms (draw-down of tubes, rods or preforms to reduced diameter preforms C03B37/0124)} · CPC title