NKT Photonics SuperK CONNECT, Product Manual, Page: 29 / 40

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Tips for steering the beam path
Figure 17 Side lobe vs main peak fiber coupling
Recovering the main peak
If you suspect a side lobe has been coupled, then follow the steps in the coarse
alignment procedure. The procedure will recover and centralize the main peak of
the beam on the fiber face, see
Procedure 3 on page 21 .
Procedure 7 Improving the coarse alignment
1. Once a partial beam appears, use a beam target to compare the orientation
of the halo which appears around the center spot. Typically the spot is offset
as
Figure 13 shows. The offset halo is created by a misaligned beam shown
as a dashed line in the illustration.
2. Align the mirrors so that the spot is centralized within its halo; shown with a
check mark in Figure 13 . At the optimum alignment point, the halo will be
minimized.
3. Once the spot is centralized, the mirrors are correctly aligned, the beam exits
the pupil of the offset pin-hole with the least loss.
No power
measured at start of
fine alignment
In the event, that even after coarse alignment, no beam emerges from an FD
inserted into the CONNECT, do the following:
1. While holding a beam detector card in front of the FD output, turn slightly
back and forth either a I or II thumbscrews on the output or input mirror,
checking for light with the detector card.
2. If light appears, stop and return to the fine alignment Procedure 5 .
3. If no light appears, do the same using the other axis’s thumbscrew.
4. Go back to the fine alignment procedure as soon as a beam appears on the
detector card.
PCF fiber
OOB side lobe Main peak
Output lateral axis
Beam wavefront
misaligned Beam wavefront
aligned