# US 2014/0153882 A1 · Optical fiber cable

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- Number: US 2014/0153882 A1
- Document ID: US20140153882A1
- Status: Published application
- Kind: A1
- Application number: 13/910,395
- Filed: 2013-06-05
- Published: 2014-06-05
- Earliest claimed: 2010-02-26
- Assignees: Sumitomo Electric Industries, Ltd.
- Applicants: Sumitomo Electric Industries, Ltd.
- Inventors: Tetsuya HAYASHI; Eisuke SASAOKA
- Web page: https://patentgrep.com/patent/US20140153882A1

## CPC

- G02B 6/02042: {Multicore optical fibres}
- G02B 6/4478: {Bending relief means}
- G02B 6/4434: {Central member to take up tensile loads}
- G02B 6/449: {Twisting}
- G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS

## Abstract

The present invention relates to an optical fiber cable incorporating a multi-core fiber provided with a plurality of cores and a cladding region. The optical fiber cable has a jacket covering the multi-core fiber. The multi-core fiber is arranged so that a hold wrap holds the cores in a state in which they are provided with a bend of not more than a fixed radius of curvature, in order to reduce crosstalk between the cores.

## Claims

### Claim at position 1

1-8. (canceled)

### Claim 9

An optical fiber cable incorporating a multi-core fiber comprising a plurality of cores each extending along a predetermined axis, and a cladding region integrally surrounding the plurality of cores, said optical fiber cable comprising a bend providing structure to provide the multi-core fiber with a bend of a radius of curvature R given by the following expression:
R
≤
1
12

β
K
2

Λ


XT
S
L
F
where Λ is an intercentral distance between adjacent cores in the multi-core fiber, LF a fiber length of the multi-core fiber corresponding to a length between repeater/regenerators in laying the optical fiber cable, β a propagation constant of each core at a first wavelength, K a coupling coefficient between adjacent cores at the first wavelength, and XTS a maximum value permitted as an average of a distribution of crosstalk after propagation of light of the first wavelength through the fiber length LF.

### Claim 10

(canceled)

### Claim 11 (depends on 9)

The optical fiber cable according to claim 9, wherein the maximum value XTS permitted as the average of the distribution of crosstalk after the propagation of the light of the first wavelength through the fiber length LF=100 km or more is 0.001.

### Claim at position 5

12-21. (canceled)

### Claim 22 (depends on 9)

The optical fiber cable according to claim 9, wherein the first wavelength is 1550 nm.

### Claim 23 (depends on 11)

The optical fiber cable according to claim 11, wherein the first wavelength is 1550 nm.