THORLABS Vytran FFS2001 Series User Manual page 61

FFS2001 Series
• Edge Alignment
• Active XY Alignment
End View Alignment (for PM fibers)
•
Active Rotation Alignment (for PM fibers)
•
Edge Alignment:
The Edge Alignment method uses image data from the CCD camera to align the fibers in the XY direction with the
Z-direction being the fiber line. This method is capable of aligning fibers of two different cladding diameters.
Active XY Alignment:
The Active XY Alignment method is used for fibers that have a core eccentricity. In such a case, the Edge Alignment
method cannot ensure a low-loss splice. Active XY Alignment uses input from an optical power meter to maximize
power transmitted between the fiber ends to determine the optimal XY alignment. Note: Connect the optical
power meter to the Analog 1 BNC input on the back panel of the FFS2001 Series.
End View Alignment:
The End View Alignment method is used for elliptical-clad fiber (PM or PZ), Panda fiber, or Bow Tie style fiber, or
a hybrid splice between any of these. These polarization-maintaining fibers are aligned rotationally as well as in
the XY-direction. Before loading the fibers into the FHBs, the fiber cladding can be coated with the pink dye
material. This enhances the contrast of the fiber structure. The PM alignment parameters (P1 and P2) must be set
correctly for each fiber type as described in the PM Alignment section.
Active Rotation Alignment:
The Active Rotation Alignment method is used for 3M elliptical-clad fiber (PM or PZ), Panda fiber, or Bow Tie style
fiber, or a hybrid splice between any of these. These polarization-maintaining fibers are aligned rotationally and
in the XY-direction, just as in the End View Alignment method above.
In addition to the End View Alignment method, the Active Rotation Alignment method uses a polarization analyzer
to precisely align the fibers rotationally. A light source is connected to the end of one of the fibers and the analyzer
is connected to the other fiber and the output of the analyzer is connected to Analog Port 1 or 2. The analyzer
contains a polarizer which is set to absorb any light in a perpendicular orientation relative to the main axis of the
fiber's PM core. The analyzer will measure the optical power produced by the system consisting of the fibers and
the polarizer. The alignment routine will align the fibers until the power reading of the analyzer is minimized.
6.4.2 Splice Method
Standard Splice
After the proper alignment is achieved, the fusion process begins. Before the filament turns on, the right-hand
fiber is moved towards the left-hand fiber a distance defined by the Pre-Push distance. The Argon flow will
increase to splice levels for about 3 seconds to clean the system of any impurities and purge the Splice Head of
remaining oxygen. The Splice Head will then move the View To Splice Distance so that the filament is centered on
the fibers (assuming no Splice Offset is set). The filament is turned on and allowed to heat up for the user-specified
amount of time (Hot Push Delay) before the right-side fiber is pushed the distance defined as Hot Push, bringing
the fibers together. This allows any discontinuities in the edges of the fibers to "round-over", and also increases
the plasticity of the glass. The hot-push method of splicing results in a smoother splice and ensures precise
alignment.
Rev. A, August 14, 2024
Chapter 6: Splicing the Fiber
Page 55