Optical fiber

Patent metadata

Field	Value
Publication number	US-9964697-B2
Application number	US-201615506943-A
Country	US
Kind code	B2
Filing date	May 24, 2016
Priority date	May 27, 2015
Publication date	May 8, 2018
Grant date	May 8, 2018

Abstract

An optical fiber includes: a core; and a clad which is formed so as to surround an outer circumference of the core concentrically with the core, the clad having at least an inner cladding layer adjacent to the outer circumference of the core and an outer cladding layer formed on an outer circumference of the inner cladding layer, wherein a refractive index of the outer cladding layer is Δ 3 , and an outer circumference radius of the outer cladding layer is r 3 , a relationship of Δ 1 max>Δ 3>Δ2 min is satisfied, a relationship of Δ 3−Δ2 min≤0.08% is satisfied, a relationship of r 1 <r 2 <r 3 is satisfied, a relationship of 0.35≤r 1 /r 2 ≤0.55 is satisfied, a cable cut-off wavelength is less than or equal to 1260 nm, and an MFD at a wavelength of 1310 nm is 8.6 μm to 9.2 μm.

First claim

The invention claimed is:

1. An optical fiber comprising:
a core; and
a clad which is formed so as to surround an outer circumference of the core concentrically with the core, the clad having at least an inner cladding layer adjacent to the outer circumference of the core and an outer cladding layer formed on an outer circumference of the inner cladding layer,
wherein in a case where a refractive index of the core is Δ 1 , a maximum refractive index of the core is Δ 1 max, and an outer circumference radius of the core is r 1 ,
a refractive index of the inner cladding layer is Δ 2 , a minimum refractive index of the inner cladding layer is Δ 2 min, and an outer circumference radius of the inner cladding layer is r 2 , and
a refractive index of the outer cladding layer is Δ 3 , and an outer circumference radius of the outer cladding layer is r 3 ,
a relationship of Δ 1 max>Δ 3 >Δ 2 min is satisfied,
a relationship of Δ 3 −Δ 2 min≤0.08% is satisfied;
a relationship of r 1 <r 2 <r 3 is satisfied,
a relationship of 0.35≤r 1 /r 2 ≤0.5 is satisfied,
a cable cut-off wavelength is less than or equal to 1260 nm, and
an MFD at a wavelength of 1310 nm is 8.8 μm to 9.2 μm.

2. The optical fiber according to claim 1 , wherein a loss increase at 1550 nm when being wound 10 times around a mandrel having a radius of 15 mm is less than or equal to 0.02 dB, a loss increase at 1550 nm when being wound once around a mandrel having a radius of 1.0 mm is less than or equal to 0.2 dB, and a sandpaper tension winding loss increase at a wavelength of 1550 nm, of an optical fiber element wire, is less than or equal to 0.3 dB/km.

3. The optical fiber according to claim 1 , wherein a sandpaper tension winding loss increase at a wavelength of 1550 nm, of an optical fiber element wire, is less than or equal to 0.15 dB/km.

4. The optical fiber according to claim 1 , wherein a sandpaper tension winding loss increase at a wavelength of 1550 nm, of an optical fiber element wire, is less than or equal to 0.10 dB/km.

5. The optical fiber according to claim 1 , wherein a relationship of 0.4≤r 1 /r 2 ≤0.5 is satisfied.

6. The optical fiber according to claim 1 , wherein a relationship of Δ 3 −Δ 2 min≤0.05% is satisfied.

Assignees

• Fujikura Ltd

Inventors

• Maruyama Ryo
• Matsuo Shoichiro
• Hirafune Shunichirou

Classifications

• G02B6/3818

  of a low-reflection-loss type (G02B6/3813 takes precedence) · CPC title

• G02B6/4289

  by inducing bending, microbending or macrobending, to the light guide · CPC title

• G02B2006/12119

  Bend · CPC title

• G02B6/125

  Bends, branchings or intersections · CPC title

• G02B6/02004 Primary

  characterised by the core effective area or mode field radius · CPC title