Multi-core optical fiber preform, multi-core optical fiber preform production method, and multi-core optical fiber production method

Patent metadata

Field	Value
Publication number	US-12459853-B2
Application number	US-202218246919-A
Country	US
Kind code	B2
Filing date	Feb 18, 2022
Priority date	Feb 22, 2021
Publication date	Nov 4, 2025
Grant date	Nov 4, 2025

Abstract

A multi-core optical fiber preform includes: a rod-shaped main cladding body having one or more main inner holes; main core rods inserted into the one or more main inner holes; and a tip continuously-installed portion disposed at one end of the rod-shaped main cladding body and including a glass rod having no core rod or having one core rod.

First claim

What is claimed is:

1 . A multi-core optical fiber preform comprising:
a rod-shaped main cladding body having one or more main inner holes; main core rods inserted into the one or more main inner holes; and a tip continuously-installed portion disposed at one end of the rod-shaped main cladding body and including a glass rod having a single core rod.

2 . The multi-core optical fiber preform according to claim 1 , wherein
the main core rods include a first core rod and a second core rod that has a dimension in an axial direction of the rod-shaped main cladding body shorter than a dimension of the rod-shaped main cladding body in the axial direction, and the first core rod is disposed at a center of the rod-shaped main cladding body.

3 . The multi-core optical fiber preform according to claim 1 , wherein
the tip continuously-installed portion includes a constant diameter portion having a constant outer diameter and a reduced diameter portion that is reduced in diameter from a tip of the constant diameter portion and protrudes from the tip, and a length of the constant diameter portion in the axial direction is equal to or larger than a length of the reduced diameter portion in the axial direction.

4 . The multi-core optical fiber preform according to claim 1 ,
wherein the tip continuously-installed portion includes a constant diameter portion having a constant outer diameter and a reduced diameter portion that is reduced in diameter from a tip of the constant diameter portion and protrudes from the tip, and a length of the constant diameter portion in the axial direction is less than a length of the reduced diameter portion in the axial direction.

5 . A multi-core optical fiber preform comprising:
a rod-shaped main cladding body having one or more main inner holes; main core rods inserted into the one or more main inner holes; and a tip continuously-installed portion that:
is disposed at one end of the rod-shaped main cladding body, and includes:
a solid constant diameter portion having a constant outer diameter; and
a solid reduced diameter portion that is reduced in diameter from a tip of the solid constant diameter portion and protrudes from the tip, wherein

the solid constant diameter portion and the solid reduced diameter portion include a glass rod having no core rod or having a single core rod.

6 . The multi-core optical fiber preform according to claim 5 , wherein
the main core rods include a first core rod and a second core rod that has a dimension in an axial direction of the rod-shaped main cladding body shorter than a dimension of the rod-shaped main cladding body in the axial direction, and the first core rod is disposed at a center of the rod-shaped main cladding body.

7 . The multi-core optical fiber preform according to claim 5 , wherein the tip continuously-installed portion includes a solid glass rod.

8 . The multi-core optical fiber preform according to claim 5 , wherein a length of the solid constant diameter portion in the axial direction is equal to or larger than a length of the solid reduced diameter portion in the axial direction.

9 . The multi-core optical fiber preform according to claim 5 , wherein a length of the solid constant diameter portion in the axial direction is less than a length of the solid reduced diameter portion in the axial direction.

Assignees

• Fujikura Ltd

Inventors

• Fukumoto Ryohei
• Takenaga Katsuhiro

Classifications

• C03B2203/34

  Plural core other than bundles, e.g. double core · CPC title

• C03B37/027

  Fibres composed of different sorts of glass, {e.g. glass optical fibres}(C03B37/0253, C03B37/028 take precedence) · CPC title

• C03B37/01251

  Reshaping the ends · CPC title

• C03B23/207

  Uniting glass rods, glass tubes, or hollow glassware (C03B23/24 takes precedence) · CPC title

• C03B23/11

  Reshaping by drawing without blowing, in combination with separating, e.g. for making ampoules · CPC title