Optical fiber and manufacturing method of optical fiber

Patent metadata

Field	Value
Publication number	US-11079537-B2
Application number	US-201916561656-A
Country	US
Kind code	B2
Filing date	Sep 5, 2019
Priority date	Mar 27, 2017
Publication date	Aug 3, 2021
Grant date	Aug 3, 2021

Abstract

An optical fiber has a core to which chlorine is added and a clad to which fluorine is added, chlorine of 9000 to 13000 ppm is added to the core, a relative refractive index difference Δ1 of the core to a pure silica glass is 0.09 to 0.13%, a relative refractive index difference Δ2 of the clad to a pure silica glass is −0.36 to −0.17%, a difference (Δ1-Δ2) between the relative refractive index difference Δ1 of the core and the relative refractive index difference Δ2 of the clad is larger than or equal to 0.30%, a mode field diameter at wavelength 1.31 μm is 8.8 to 9.6 μm, and a stress difference occurring at an interface between the core and the clad is lower than or equal to 60 MPa.

First claim

The invention claimed is:

1. An optical fiber comprising:
a core to which chlorine is added; and
a clad to which fluorine is added,
wherein chlorine of 9000 to 13000 ppm is added to the core,
wherein a relative refractive index difference Δ1 of the core to a pure silica glass is 0.09 to 0.13%,
wherein a relative refractive index difference Δ2 of the clad to a pure silica glass is −0.36 to −0.17%,
wherein a difference (Δ 1 −Δ 2 ) between the relative refractive index difference Δ 1 of the core and the relative refractive index difference Δ2 of the clad is larger than or equal to 0.30%,
wherein a mode field diameter at a wavelength of 1.31 μm is 8.8 to 9.6 μm,
wherein a stress difference occurring at an interface between the core and the clad is lower than or equal to 60 MPa, and
wherein a value of a ratio Δ 2 /Δ 1 of the relative refractive index difference Δ 2 of the clad to the relative refractive index difference Δ 1 of the core is −3.3 to −1.5.

2. The optical fiber according to claim 1 , wherein a concentration of chlorine added to the core is higher than or equal to 10000 ppm.

3. The optical fiber according to claim 1 , wherein the relative refractive index difference Δ 2 of the clad is higher than or equal to −0.30%.

4. The optical fiber according to claim 1 , wherein a stress difference occurring at the interface between the core and the clad is lower than or equal to 30 MPa.

5. The optical fiber according to claim 1 , wherein transmission loss of light in a 1.55 μm-wavelength band is lower than or equal to 0.174 dB/km.

6. The optical fiber according to claim 1 , wherein transmission loss of light in a 1.31 μm-wavelength band is lower than or equal to 0.314 dB/km.

7. An optical fiber cable using the optical fiber according to claim 1 .

Assignees

• Furukawa Electric Co Ltd

Inventors

• Miyabe Ryo
• Aiso Keiichi

Classifications

• C03C13/04

  Fibre optics, e.g. core and clad fibre compositions (light guides G02B6/00) · CPC title

• 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

• C03B2201/12

  doped with fluorine (C03B2201/14 takes precedence) · CPC title

• C03B37/03

  Drawing means, e.g. drawing drums {; Traction or tensioning devices} · CPC title

• C03B2205/42

  Drawing at high speed, i.e. > 10 m/s · CPC title