Furukawa electric S178, Руководство пользователя

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General Information
2-7
Core Diameter/Axis offset
Because the optical signal is transmitted through the core of the fiber, it is important to
understand how the cores of the two fibers being spliced together compare. The following
general formula can be used to show the effects of core offset on the splice loss. The formula is
only theoretical and does not take into account other extrinsic factors such as cleave quality or
dust contamination, and intrinsic factors such as core non-circularity and numerical aperture.
mode field diameter A [um] mode field diameter B [um]
optical power
INPUT
optical power
OUTPUT
core axis offset d [um]
right fiber left fiber
splice loss
⎥
⎥
⎦
⎤
⎢
⎢
⎣
⎡
⎟⎟
⎠
⎞
⎜⎜
⎝
⎛
+
− ⎟
⎠
⎞
⎜
⎝
⎛
+
× = × =
2 2
2
2
2 2
10 10
2 2
log 10 log 10 ] [
B A
d
EXP
B A
AB
INPUT
OUTPUT
dB spliceloss