Manufacturing method of multicore fiber preform, multicore fiber preform, and multicore fiber

Patent metadata

Field	Value
Publication number	US-2022003921-A1
Application number	US-202117448077-A
Country	US
Kind code	A1
Filing date	Sep 20, 2021
Priority date	Mar 27, 2019
Publication date	Jan 6, 2022
Grant date	—

Abstract

A multicore fiber includes: n pieces of first core regions in a circular shape with a radius r1 that are arranged about points P11 to P1n, and that has a first core portion and a first cladding portion; a second core region in a circular shape with a radius R1 that is arranged about the point a1, and that has a second core portion and a second cladding portion; and a cladding region that is formed on an outer circumferences of the first core region and the second core region. Further, abutting surfaces that are flat surfaces abutting on each other are formed in portions on the outer circumferences of the first core region and the second core region.

First claim

1 . A multicore fiber comprising:
n pieces of first core regions in a circular shape with a radius r 1 that are arranged about points P 11 to P 1 n , and that has a first core portion and a first cladding portion formed on an outer circumference of the first core portion by setting the points P 11 to P 1 n at positions, distances of which are X 11 to X 1 n , respectively, from a point a 1 , on straight lines dividing an end surface in to n pieces to have an equal central angle about the point a 1 of the end surface such that X 1 max−r 1 <R 1 <X 1 min is satisfied, where a maximum value of X 11 to X 1 n is X 1 max, and a minimum value thereof is X 1 min; a second core region in a circular shape with a radius R 1 that is arranged about the point a 1 , and that has a second core portion and a second cladding portion formed on an outer circumference of the second core portion; and a cladding region that is formed on an outer circumferences of the first core region and the second core region, wherein abutting surfaces that are flat surfaces abutting on each other are formed in portions on the outer circumferences of the first core region and the second core region.

2 . The multicore fiber according to claim 1 , wherein
a cladding region having a softening temperature lower than the first cladding portion and the cladding region is arranged in place of the second core region.

3 . A multicore fiber comprising:
n pieces of first core regions in a polygonal shape that are arranged to have a center of gravity at points P 21 to P 2 n , and that has a first core portion and a first cladding portion formed on an outer circumference of the first core portion, by setting the points P 21 to P 2 n at positions, distances of which are X 21 to X 2 n , respectively, from a point a 2 , on straight lines dividing an end surface into n pieces to have an equal central angle about the point a 2 of the end surface such that a plurality of overlap portions in which adjacent polygons overlap each other at least in a part thereof are formed; a second core region in a polygonal shape that is arranged about the point a 1 , that has a second core portion and a second cladding portion formed on an outer circumference of the second core portion, and that includes all of the overlap portions; and a cladding region that is formed on an outer circumferences of the first core region and the second core region, wherein abutting surfaces that are flat surfaces abutting on each other are formed in portions on the outer circumferences of the first core region and the second core region.

4 . The multicore fiber according to claim 3 , wherein
a cladding region having a softening temperature lower than the first cladding portion and the cladding region is arranged in place of the second core region.

5 . A multicore fiber comprising:
n pieces of first core regions in a circular shape with a radius r 1 that are arranged about points P 11 to P 1 n , and that have a first core portion and a first cladding portion formed on an outer circumference of the first core portion, by setting the points P 11 to P 1 n at positions, distances of which are X 11 to X 1 n , respectively, from a point a 1 , on straight lines dividing an end surface into n pieces to have an equal central angle about the point a 1 of the end surface such that X 1 max−r 1 <R 1 <X 1 min is satisfied when a maximum value of X 11 to X 1 n is X 1 max, and a minimum value thereof is X 1 min; and a low-temperature-softening cladding region that is arranged about the point a 1 , and that has a softening temperature lower than the first cladding portion.

Assignees

• Furukawa Electric Co Ltd

Inventors

• Takahashi Masanori
• Maeda Koichi
• Arai Shinichi
• Sugizaki Ryuichi
• Tsukamoto Masayoshi

Classifications

• C03B2203/34

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

• C03B37/01231

  to form a longitudinal hole, e.g. by drilling · CPC title

• C03B37/01222

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

• G02B6/02042 Primary

  Multicore optical fibres · CPC title

• C03B37/012

  Manufacture of preforms for drawing fibres or filaments · CPC title