THORLABS BC207UV, Operating Manual

Page: 121 / 181

BC207 Series
Chapter 6: Operation Instructions
Rev: 8.1, 10-Jan-2022
Page 114
© 2022 Thorlabs
6.3.7.6 M² Measurement Results
After a successful M
2
measurement, the Beam Quality Measurement window shown below
appears.
The green bulb indicates that the measurement was successful and fulfills the ISO 11146
standards:
In the case that beam criteria different from the ISO standard beam width criteria were used
(see
M² Settings ), a successful measurement is shown without the ISO indication:
In general, the X' and Y' axes do not coincide with the lab system (described by the X and Y
axes). Furthermore, the M² value for X' is independent from the one for Y'. For highly elliptical
beams, such as those from semiconductor lasers, M
2
X' and M
2
Y' will differ much more than in
this example.
Diagram Legend
Beam Diameter X'
Beam Diameter Y'
Hyperbolic Fit X'
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