TEM Aligna 4D - Overlaying Three Laser Beams with Commonly Stabilized Path

Aligna
®
4D User Manual
30 / 84
5.9 Overlaying Three
Laser Beams with Com-
monly Stabilized Path
In the following, the same procedure
is sketched for three overlayed
beams with a commonly stabilized
long path.
All beams "A", "B", "C" are overlaid
at the tube entrance, by help of
dielectric beam combiners "DBC1"
and "DBC2", regarding the
"electronical iris" "AimPD1".
By help of matrix-4D-movement the
beams are also overlaid at the target
table, regarding "AimPD2".
The common path is stabilized with
full servo bandwidth regarding PSD
4D, which measures one of the beams (or an average of all).
If all wavelengths can be detected by the PSD4D, this detector can also overtake the task of
"AimPD2". This however is only possible if all wavelengths are in the range of the same PSD
(for example 350 nm…1100 nm).
(optional PSD 2D)
Overlaying of Three Beams
Fast Stabilization of One Beam
M1A
M1B
M1C
M2A
M2B
M2C
MoA
MoA
MoA
MoA
MoA
MoPiA
AimPD 1
AimPD 2
DBC1
DBC2
(BSP)
BeamLine
Tube
Laser A
Laser B
Laser C
M3
MoPiA
BSM
PSD 4D