THORLABS M2MS, Руководство по эксплуатации

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BP209 Series 7 Operation Instructions
Rev: 8.1, 14-Feb-2022 © 2022 Thorlabs Page 125
7.2.8.3 Divergence Measurement Settings
For a successful and reliable measurement, the appropriate measurement settings are essen-
tial. Click to to enter the Divergence Measurement Settings .
Beam Width
The Beam Width calculation is based on an ellipse-based
approximation with two possible clip levels. At the begin-
ning of a measurement a reference angle is determined by
averaging over 10 frames. This angle is then used to eval-
uate all following frames and ellipses.
Measurement Parameters
The wavelength is not relevant for divergence measure-
ment.
Measurement Range
determines the distance from the starting to the stopping
point over which the sleigh is driven during the measure-
ment.
Start has to be at least 5 mm smaller than Stop and
0 mm. Valid values for Stop are
5 mm < Stop < stage length.
Note
It is advisable to set up a scan range > 40 mm to ensure
higher accuracy. A scan over the entire translation length
is often the best choice.
Timeout is the waiting time until valid data can be retrieved from the Beam Profiler (e.g. in case
of slow travel speed)
Stage Position After Scan
is not relevant for divergence measurement.
Angle Unit
Degree or milliradian can be selected.
Reset
Restores the default settings for divergence settings:
Parameter Default Setting
Beam Width Beam Width Clip (1/e²)
Start 0 mm
Stop 200 mm
Min. Data Points 10
Timeout 15 sec
Device Settings
It is important to set Gain and Bandwidth of the Beam Profiler (see Slit Beam Profiler Parame-
ter ) to Auto.
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