Connection loss difference measurement method, equipment and program
In order to achieve the above object, the present invention individually inputs light pulses to a first core and a second core at one end of a non-coupled multicore fiber having a connection portion, and individually acquires OTDR waveforms regarding the first core and the second core, calculates ratios between backscattering intensity regarding the first core and backscattering intensity regarding the second core, at at least two points including one point on one end side with respect to the connection portion and one point on another end side with respect to the connection portion, based on the acquired OTDR waveforms, and calculates a ratio between the calculated ratio on the one end side and the calculated ratio on the another end side.
1 . A connection loss difference measuring method, comprising:
individually inputting light pulses to a first core and a second core at one end of a non-coupled multicore fiber having a connection portion, and individually acquiring OTDR waveforms regarding the first core and the second core;
calculating ratios between backscattering intensity regarding the first core and backscattering intensity regarding the second core, at at least two points including one point on one end side with respect to the connection portion and one point on another end side with respect to the connection portion, based on the acquired OTDR waveforms; and
calculating a ratio between the calculated ratio on the one end side and the calculated ratio on the another end side.
2 . The connection loss difference measuring method according to claim 1 , wherein
Expression (C1) is used as backscattering intensity P m (z) regarding the first core at a distance z from the one end, and Expression (C2) is used as backscattering intensity P n (z) regarding the second core at the distance z,
[
Math
.
C1
]
P
m
(
z
)
=
{
P
m
0
α
s
(
z
)
B
(
z
)
exp
(
-
2
α
m
z
)
(
z
≤
z
1
)
η
m
P
m
0
α
s
(
z
)
B
(
z
)
exp
(
-
2
α
m
z
)
(
z
≥
z
1
)
(
C1
)
[
Math
.
C2
]
P
n
(
z
)
=
{
P
n
0
α
s
(
z
)
B
(
z
)
exp
(
-
2
α
n
z
)
(
z
≤
z
1
)
η
n
P
n
0
α
s
(
z
)
B
(
z
)
exp
(
-
2
α
n
z
)
(
z
≥
z
1
)
(
C2
)
where z 1 represents a distance from the one end to the connection portion, P m0 represents intensity of the light pulse input to the first core, P n0 represents intensity of the light pulse input to the second core, as represents a Rayleigh scattering coefficient, B represents a backscattered light capturing rate, α m represents a fiber loss coefficient in the first core, α n represents a fiber loss coefficient in the second core, η m represents connection efficiency in the first core, and In represents connection efficiency in the second core.
3 . A connection loss difference measuring method, comprising:
individually inputting light pulses to a first core and a second core at one end of a non-coupled multicore fiber having a connection portion, and individually acquiring OTDR waveforms regarding the first core and the second core;
obtaining, for each core, a loss of backscattered light intensity, at the connection portion, based on the OTDR waveforms; and
calculating a ratio between the loss of the first core and the loss of the second core.
4 . A connection loss difference measuring device, comprising:
an optical time domain reflectometer that individually acquires OTDR waveforms regarding a first core and a second core at one end of a non-coupled multicore fiber having a connection portion;
a processor; and
a storage medium having computer program instructions stored thereon, when executed by the processor, perform to:
calculate ratios between backscattering intensity regarding the first core and backscattering intensity regarding the second core, at at least two points including one point on one end side with respect to the connection portion and one point on another end side with respect to the connection portion, based on the OTDR waveforms, and calculate a ratio between the calculated ratio on the one end side and the calculated ratio on the another end side.
5 . The connection loss difference measuring device according to claim 4 , wherein the computer program instructions further perform to
use Expression (C3) as backscattering intensity P m (z) regarding the first core at a distance z from the one end, and
use Expression (C4) as backscattering intensity P n (z) regarding the second core at the distance z,
[
Math
.
C3
]
P
m
(
z
)
=
{
P
m
0
α
s
(
z
)
B
(
z
)
exp
(
-
2
α
m
z
)
(
z
≤
z
1
)
η
m
P
m
0
α
s
(
z
)
B
(
z
)
exp
(
-
2
α
m
z
)
(
z
≥
z
1
)
(
C3
)
[
Math
.
C4
]
P
n
(
z
)
=
{
P
n
0
α
s
(
z
)
B
(
z
)
exp
(
-
2
α
n
z
)
(
z
≤
z
1
)
η
n
P
n
0
α
s
(
z
)
B
(
z
)
exp
(
-
2
α
n
z
)
(
z
≥
z
1
)
(
C4
)
where z 1 represents a distance from the one end to the connection portion, P m0 represents intensity of a light pulse input to the first core, P n0 represents intensity of a light pulse input to the second core, α s represents a Rayleigh scattering coefficient, B represents a backscattered light capturing rate, α m represents a fiber loss coefficient in the first core, α n represents a fiber loss coefficient in the second core, η m represents connection efficiency in the first core, and In represents connection efficiency in the second core.
6 . A connection loss difference measuring device, comprising:
an optical time domain reflectometer that individually acquires OTDR waveforms regarding a first core and a second core at one end of a non-coupled multicore fiber having a connection portion;
a processor; and
a storage medium having computer program instructions stored thereon, when executed by the processor, perform to:
obtain, for each core, a loss of backscattered light intensity, at the connection portion, based on the OTDR waveforms, and calculate a ratio between the loss of the first core and the loss of the second core.