Optical fiber

Patent metadata

Field	Value
Publication number	US-11460632-B2
Application number	US-202017296174-A
Country	US
Kind code	B2
Filing date	Nov 6, 2020
Priority date	Nov 8, 2019
Publication date	Oct 4, 2022
Grant date	Oct 4, 2022

Abstract

An optical fiber includes a glass portion, a primary coating layer, and a secondary coating layer. In the optical fiber, a value of microbend loss characteristic factor FμBL_GO is 2.6 ([GPa−1·μm−10.5·dB/turn]·10−27) or less, when represented byFμBL_GO=FμBL_G×FμBL_Oby using geometry microbend loss characteristic FμBL_G and optical microbend loss characteristic FμBL_O.

First claim

The invention claimed is:

1. An optical fiber comprising
a glass portion comprising a core and a clad surrounding the core;
a primary coating layer covering the clad; and
a secondary coating layer covering the primary coating layer,
wherein a value of microbend loss characteristic factor F μBL_GO ([GPa −1 ·μm −10.5 ·dB/turn]·10 −27 ) is 2.6 ([GPa −1 ·μm −10.5 ·dB/turn]·10 −27 ) or less when represented by
F μBL_GO =F μBL_G ×F μBL_O ,

wherein geometry microbend loss characteristic F μBL_G (GPa −1 ·μm −10.5 ·10 −27 ) of the optical fiber is represented by

⁢

F

μ
⁢

⁢
BL
⁢

⁢
_
⁢

⁢
G

=

K
S
2

H
f
2

×

D
0
0.375

×

H
0
0.625

K
s

=

E
p

⁢

d
f

t
p

,

H
f

=

π
4

⁢

E
g

⁡

(

d
f

2

)

4

,

D
0

=

E
p

+

(

t
s

R
s

)

3

⁢

E
s

,

H
0

=

π
4

⁢

E
s

⁡

(

R
s
4

-

R
p
4

)

,

where
κs (MPa) is a spring coefficient of the primary coating layer,
H f (MPa·μm 4 ) is a bending rigidity of the glass portion,
D 0 (MPa) is a deformation resistance of the secondary coating layer,
H 0 (MPa·μm 4 ) is a bending rigidity of the secondary coating layer,
E g (GPa) is a Young's modulus of the glass portion,
E p (MPa) is a Young's modulus of the primary coating layer,
E s (MPa) is a Young's modulus of the secondary coating layer,
d f (μm) is an outside diameter of the glass portion,
R p (μm) is a radius of an outer peripheral surface of the primary coating layer,
R s (μm) is a radius of an outer peripheral surface of the secondary coating layer,
t p (μm) is a thickness of the primary coating layer, and
t s (μm) is a thickness of the secondary coating layer, and

wherein optical microbend loss characteristic F μBL_O (dB/turn) of the optical fiber is represented by

F

μ
⁢

⁢
BL
⁢

⁢
_
⁢

⁢
O

=

2
⁢
w

λ

c
⁢
c

×

α
BL

,

where
2w (μm) is a mode field diameter of light having a wavelength of 1310 nm propagating through the optical fiber,
λ cc (μm) is a cable cutoff wavelength of the optical fiber, and
α BL (dB/turn) is a macrobend loss of the optical fiber at a wavelength of 1625 nm and a radius of 10 mm.

2. The optical fiber according to claim 1 , wherein the value of the microbend loss characteristic factor is 1.3 ([GPa −1 ·μm −10.5 ·dB/turn]·10 −27 ) or less.

3. The optical fiber according to claim 1 , wherein a coating thickness of a su

Assignees

• Fujikura Ltd

Inventors

• Maruyama Ryo

Classifications

• C03C2201/11

  containing chlorine · CPC title

• G02B6/02395 Primary

  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

• G02B6/4409

  for ribbons · CPC title

• G02B6/4403

  with ribbon structure (G02B6/4429, G02B6/4439, G02B6/4479 take precedence) · CPC title

• C03C3/06 Primary

  with more than 90% silica by weight, e.g. quartz {(C03C3/045 takes precedence)} · CPC title