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ADVANCED OPERATION - Splicing program structure: Splicing process
Threshold type test
When you are presented with a new fiber combination it is
highly advisable to run the Threshold type test. You do so by
setting the parameter THRESHOLD TYPE to Threshold type
test (see page 43, for instructions as to how you edit param-
eters), as well as setting up the test configuration shown
below. During the Threshold type test, you will get an index
profile of the two fibers based on how they behave during
heating (see picture on previous page). The result of the test
will be a value for the Index limit, as well as, the information
necessary to choose a Threshold type. While the test is
running, it is recommended to do a splice loss measurement,
as well, which you do by pressing the #-button when the loss
is at a minimum. You can save up to three data points (eg.
press the #-button three times) for the splice loss measure-
ment, and the final value will be their average.
Threshold types
DIFFERENCE
When the difference between the two index profiles
decreases during splicing, it is possible to determine the
optimal match by just measuring the difference between the
two index profiles, stopping the splicing sequence when the
difference is at a minimum. See also on next page.
LEFT INDEX
and
When the difference between the two index profiles does not
RIGHT INDEX
become smaller during splicing, it is necessary to measure the
absolute indexes of the fibers, rather than their difference. You
should measure the fiber who has the least variation in its
index profile.
If the left fiber’s index varies least, choose LEFT INDEX
If the right fiber’s index varies least, choose RIGHT INDEX.
HIGHER INDEX
When one fiber always has a higher index profile than the
other or when the profiles cross frequently during heating, it is
best to measure the higher absolute index.
HIGHER START
It is also possible to choose to measure the absolute index of
the fiber that has the higher index in the first cycle of
measurement.
20 m Single fiber or
Dispersion shifted fiber
1. Light source
2. Lightwave isolator
3. 3 spools with a diameter of approximately 5-8 cm for mode filtering
4. Splicer: FSU 995 FA
5. Detector
>1 m Erbium fiber
1
2
3
4
5
Set-up for the threshold type test