Connector structure and connector connection structure

Patent metadata

Field	Value
Publication number	US-9829652-B2
Application number	US-201615134343-A
Country	US
Kind code	B2
Filing date	Apr 20, 2016
Priority date	Oct 29, 2013
Publication date	Nov 28, 2017
Grant date	Nov 28, 2017

Abstract

In the present invention, a connector structure comprises a multi-core fiber and a ferrule. The multi-core fiber comprises a plurality of cores and a cladding that surrounds the cores. The ferrule holds the multi-core fiber. A tip of the multi-core fiber protrudes from an end face of the ferrule. A relation Δ≦14.8/a is satisfied. In the formula, Δ (μm) is a difference between a maximum protrusion height and a minimum protrusion height from an end face of the ferrule in a reference circle at the tip of the multi-core fiber. The reference circle is a minimum circle that includes all mode field diameters of the plurality of the cores having a center of cross section of the multi-core fiber as its center. And a (μm) is a radius of the reference circle.

First claim

What is claimed is:

1. A connector structure comprising:
a multi-core fiber, which comprises a plurality of cores and a cladding that surrounds the cores; and
a ferrule that holds the multi-core fiber; wherein
 a tip of the multi-core fiber protrudes from an end face of the ferrule; and
 a relation Δ≦14.8/a is satisfied, wherein
Δ (μm) is a difference between a maximum protrusion height and a minimum protrusion height from an end face of the ferrule in a reference circle at the tip of the multi-core fiber;
the reference circle is a minimum circle that includes all mode field diameters of the plurality of the cores having a center of cross section of the multi-core fiber as its center; and
a (μm) is a radius of the reference circle, wherein
one of the plurality of cores is located at the center of cross-section of the multi-core fiber, and
the core that is located at the center has a protrusion height from the end face of the ferrule greater than protrusion heights of the other cores.

2. The connector structure according to claim 1 , wherein
the maximum protrusion height of the multi-core fiber from an end face of the ferrule is 5 μm or more.

3. The connector structure according to claim 1 , wherein
a thickness of the cladding that is formed on a periphery of the reference circle is 50 μm or less.

4. The connector structure according to claim 1 , wherein
the ferrule holds a plurality of the multi-core fibers.

5. A connector structure comprising:
a multi-core fiber, which comprises a plurality of cores and a cladding that surrounds the cores; and
a ferrule that holds the multi-core fiber; wherein
 a tip of the multi-core fiber protrudes from an end face of the ferrule; and
 a relation Δ≦14.8/a is satisfied, wherein
Δ (μm) is a difference between a maximum protrusion height and a minimum protrusion height from an end face of the ferrule in a reference circle at the tip of the multi-core fiber;
the reference circle is a minimum circle that includes all mode field diameters of the plurality of the cores having a center of cross section of the multi-core fiber as its center; and
a (μm) is a radius of the reference circle, wherein

a tip part of the multi-core fiber has an approximately flat flat-portion and a chamfer-portion formed on a circumference of the flat-portion; and
the reference circle is included within the flat-portion.

6. The connector structure according to claim 5 , wherein
the maximum protrusion height of the multi-core fiber from an end face of the ferrule is 5 μm or more.

7. The connector structure according to claim 5 , wherein
a thickness of the cladding that is formed on a periphery of the reference circle is 50 μm or less.

8. The connector structure according to claim 5 , wherein
the ferrule holds a plurality of the multi-core fibers.

9. A connector connection structure including:
a pair of connector structures each of which comprises:
a multi-core fiber, which comprises a plurality of cores and a cladding that surrounds the cores; and
a ferrule that holds the multi-core fiber, wherein:
a tip of the multi-core fiber of a first of the connector structures does not protrude from an end face of the ferrule but is on an approximately same plane;
a tip of the multi-core fiber of a second of the connector structures protrudes from the end face of the ferrule;

in the pair of the connector structures, tips of each of the multi-core fibers are pressed so that the multi-core fibers are optically connected facing each other;
the end face of the multi-core fiber of the first connector structure is approximately flat; and

a relation Δ 2 ≦29.6/a is satisfied, wherein:
Δ 2 (μm) is a difference between a maximum protrusion height and a minimum protrusion height from an end face of the ferrule in a reference circle at the tip of the multi-core fiber of the second connector structure;
the reference circle is a minimum circle that includes all mode field diameters of the plurality of the cores having a center of cross section of the multi-core fiber as its center; and
a (μm) is a radius of the reference circle.

10. The connector structure according to claim 9 , wherein
one of the plurality of cores of the multi-core fiber in the second connector structure is located at the center of cross-section of the multi-core fiber; and
the core that is located at the center has a protrusion height from the end face of the ferrule greater than protrusion heights of the other cores.

11. A connector connection structure using a pair of connector structures each of which comprises:
a multi-core fiber, which comprises a plurality of cores and a cladding that surrounds the cores; and
a ferrule that holds the multi-core fiber; wherein
a tip of the multi-core fiber of each of the pair of the connector structures protrudes from an end face of the ferrule;
in the pair of the connector structures, tips of each of the multi-core fibers are pressed so that the multi-core fibers are optically connected facing each other; and
a relation Δ 1 +Δ 2 (m)≦29.6/a is satisfied, wherein:
Δ 1 and Δ 2 are differences between a maximum protrusion height and a minimum protrusion height from an end face of the ferrule in a reference circle at the tip of the multi-core fiber of each of the pair of the connector structures;
the reference circle is a minimum circle that includes all mode field diameters of the plurality of the cores having a center of cross section of the multi-core fiber as its center; and
a (μm) is a radius of the reference circle of the multi-core fiber of the pair of the connector structures.

Assignees

• Furukawa Electric Co Ltd

Inventors

• Watanabe Kengo
• Saito Tsunetoshi

Classifications

• G02B6/403

  of the ferrule type, connecting a pair of ferrules · CPC title

• G02B6/3863

  fabricated by using polishing techniques (grinding of the fibre ends B24B19/226) · CPC title

• G02B6/3882

  using rods, pins or balls to align a pair of ferrule ends · CPC title

• G02B6/04 Primary

  formed by bundles of fibres (G02B6/24 takes precedence) · CPC title

• G02B6/3885 Primary

  Multicore or multichannel optical connectors, i.e. one single ferrule containing more than one fibre, e.g. ribbon type (optical ribbon cable G02B6/4403, G02B6/448) · CPC title