THORLABS BC207UV, Operating Manual

Page: 142 / 181

BC207 Series Chapter 6: Operation Instructions
Page 135
MTN026962-D02
6.3.8.3 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 max. waiting time for a valid camera image. This is to allow the Auto exposure
function to obtain a valid camera image
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
4 s Diameter (ISO Standard)
Start 0 mm
Stop 200 mm
Min. Data Points 10
Timeout 15 sec
Calculation Area
The settings for the Calculation Area can be made in the Beam Settings Panel . During a
Beam Quality Measurement (M
2
or Divergence) the Automatic Calculation Area is enabled by
default for effective noise reduction. Reflections and artifacts from filters, lenses or other optical
elements can be suppressed as well using the automatic Calculation Area which is close to the
beam profile.
40