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ADVANCED OPERATION - Splicing program structure: Fiber type
Titanium fiber
TITANIUM FIBER
Pre-defined program: 03
Hot image of titanium fibers
Depressed cladding fiber
DEPRESS. CLAD. FIBER
Pre-defined program: 02
Hot image of depressed cladding fibers
Dispersion shifted fiber
DEPRESS. CLAD. FIBER
or
INVISIBLE CORE FIB.
Pre-defined program: 02
Hot image of dispersion shifted fibers
Silica core fiber
INVISIBLE CORE FIB.
Pre-defined program: 02
Depressed cladding fibers are doped with both germanium in
the core and flourine in the inner part of the cladding. The
purpose of this double-doping is to reduce dispersion at a
chosen wavelength. As with titanium doped fibers, the in-
creased radiation from the dopants makes it difficult to distin-
guish the core in hot images, so a special filtering technique
must be applied. The other difficulty you might encounter is
that the dopants have a tendency to diffuse during splicing,
resulting in higher splice loss.
Like depressed cladding fiber, dispersion shifted fiber is
designed to achieve a low level of dispersion at a chosen
wavelength. And again like depressed cladding fiber, the
dopants used to create the necessary gradation of refractive
indexes, make the core very difficult to see in hot images.
Because of their similarities, you can specify “DEPRESS,
CLAD. FIBER” with dispersion shifted fiber; however, if the
splice loss is too high using this fiber type specification, you
should select “INVISIBLE CORE” instead.
Silica core has the same difficulty as dispersion shifted fiber:
namely that the high level of dopants (in this case flourine in
the cladding) can make it nearly impossible to see the core.
Titanium fibers have an outer layer doped with titanium diox-
ide, which has the result of increasing the fiber’s resistance to
fatigue. A splicing difficulty is that this titanium doped layer,
when heated, emits more radiation than the cladding, making
it hard to see the core in hot images. Another peculiarity is
that splicing titanium fibers contaminates the electrodes
more quickly than other splicing combinations. To minimize
this contamination, as well as the risk of “matchsticking”--a
phenomenon where the fibers do not fuse, but rather melt at
their tips forming round balls at their ends--a program with a
lower current should be used.