Primes HP-MSM-HB, Оригинальное руководство пользователя

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105 Revision 00 EN - 01/2021
HP-MSM-HB
35,0(6
23.3.3 Errors from incorrect measurement window size
The entire laser beam must be within the measurement window for correct normalization of the volume of the
measured distribution. Since the intensity distribution, in principle, extends infinitely, a fraction of the beam
power is always outside the measuring range.
In the following, the normalization of beam radius is proportional by half to the window size. This size is de-
fined as the Fill Factor (F).
(1.8)
Resolution: 256 steps
50
-50
0
0
0.25
-0.25
-0.5
0.5
1
-1
-2
2
0.2 0.4 0.6 0.8
TEM
00
1.0
Failur
e in %
Failure because of Offset Displacement
Theoretical filling factor
Filling factor: Beam diameter
Width of measuring window
Fig. 23.7: Error During Beam Radius Calculation by Offset of the zero level Plane for Various Offset Values (Gaussian
Intensity Distribution)
In Fig. 23.7 on page 105, the effect of a Fill Factor greater than 0.7 can clearly be seen. For Gaussian-like
beams, the Fill Factor should be held between 0.4 and 0.6 to minimize errors. For Top-Hat distributions, the
limit is around 0.9.