Multi-core optical fiber and multi-core optical fiber cable

Patent metadata

Field	Value
Publication number	US-2016266307-A1
Application number	US-201414409698-A
Country	US
Kind code	A1
Filing date	Jun 20, 2014
Priority date	Jul 4, 2013
Publication date	Sep 15, 2016
Grant date	—

Abstract

The present embodiment relates to a multi-core optical fiber and others having an excellent transmission capacity per unit cross-sectional area and spectral efficiency and being easy to manufacture. The multi-core optical fiber has a plurality of cores, a cladding, and a coating and has an appropriately-set neighboring core pitch, cable cutoff wavelength, confinement index of light into each core, cladding outer diameter, and neighboring intercore power coupling coefficient, and a relationship among a minimum of Formula Λ/(r clad −OCT min ), a maximum of the Formula, and a core count is present under a predetermined relationship.

First claim

1 . A multi-core optical fiber comprising: a plurality of cores each extending along a central axis and comprised of silica-based glass; a common cladding covering each of the plurality of cores and comprised of silica glass; and a coating provided on an outer peripheral surface of the common cladding and comprised of a material different from silica glass,
wherein in a cross section of the multi-core optical fiber perpendicular to the central axis, the plurality of cores are arranged in an equilateral-triangular lattice pattern and a neighboring core pitch Λ [μm] being a distance between centers of neighboring cores is constant, wherein a cable cutoff wavelength λ cc [μm] of each of the plurality of cores is not more than 1.53 μm, wherein when a theoretical cutoff wavelength is represented by λ cth [μm] and a mode field diameter by MFD [μm], MFD/(λ cc ) 0.657 as a confinement index of light into each of the plurality of cores is not more than 8.2 at the wavelength of 1.55 μm, or, MFD/(λ cth ) 0.720 as a confinement index of light into each of the plurality of cores is not more than 6.9 at the wavelength of 1.55 μm, wherein an outer diameter 2r clad [μm] of the common cladding is from 115 μm to 250 μm, wherein when the multi-core optical fiber is bent in a radius of curvature R in the range of 0.3 m to 3 m over the entire length thereof, both of a neighboring intercore power coupling coefficient and a neighboring identical intercore power coupling coefficient are not more than 2.3×10 −6 /km at the wavelength of 1625 nm and at least either one of the neighboring intercore power coupling coefficient and the neighboring identical intercore power coupling coefficient is not less than 3.6×10 −9 /km at the wavelength of 1530 nm, wherein when OCT represents a shortest distance from a center of a core located at an outermost periphery out of the plurality of cores, to an outer peripheral surface of the common cladding, OCT 0.01dB/km [μm] by which a transmission loss increase in the coating theoretically becomes 0.01 dB/km and OCT 0.001dB/km [μm] by which the transmission loss increase in the coating theoretically becomes 0.001 dB/km, are values obtained by Formula (1) or Formula (2) below using MFD [μm] at the wavelength of 1625 μm,

{

OCT

0.01



dB


/


km

=

1.625


[

-
7.78

×

10

-
2



(

MFD

(

λ
bc

)

0.869

)

2

+

3.02


(

MFD

(

λ
bc

)

0.869

)

]

OCT

0.001



dB


/


km

=

1.625


[

-
8.48

×

10

-
2



(

MFD

(

Assignees

• Sumitomo Electric Industries

Inventors

• Hayashi Tetsuya

Classifications

• G02B6/02395

  Glass optical fibre with a protective coating, e.g. two layer polymer coating deposited directly on a silica cladding surface during fibre manufacture (G02B6/02052, G02B6/02057, G02B6/024, G02B6/032, G02B6/105, G02B6/14 take precedence; coating on fibre gratings G02B6/02104; multilayer core or cladding G02B6/036; reinforcing splice joints G02B6/2558; optical cables, i.e. comprising protective structures external to the protective coating such as a jacket or plural coated optical fibres G02B6/44; coating of glass to obtain optical fibres C03C25/104) · CPC title

• G02B6/02042 Primary

  Multicore optical fibres · CPC title

• G02B6/4413

  Helical structure · CPC title