© 2011 Thorlabs
115Operating the Beam Profiler
Divergence Asymmetry
Divergence Asymmetry is the quotient of divergence angles in Y and X scan
directions. Values differing from 1.0 indicate that the beam ellipticity is changing with
z position, for instance an elliptical beam is focussed to a round spot.
Astigmatism
Astigmatism is known as the effect that the beam waist in X and Y scan direction is
not at the same z position. So there is a difference between the positions of minimal
spot diameters z
0y
and z
0y
.
Note
All results are calculated from the applied fit!
Save Test Results
Save measurement data as ASCII file (*.txt) or as EXCEL spreadsheet (*.xls).
Save measurement data as *.pdf file.
Zooming and panning the display
Both axes in M² measurement result display can be zoomed and also panned.
Panning: Place the mouse pointer onto the axis to be shifted. Press and hold left
mouse button - the pointer changes to or depending on the axis direction.
Move the mouse as the mouse pointer arrows indicate in order to move through the
entire measurement data range for stage position resp. beam diameter.
Zoom: Place the mouse pointer onto the axis to be shifted. Press and hold right
mouse button - the pointer changes to or depending on the axis direction.
Move the mouse as the mouse pointer arrows indicate in order to zoom in or out the
measurement data range for stage position resp. beam diameter.
Display of results at a certain Z position
After measurement is finished, the calculated data for Beam Diameter (X') and
Beam Diameter (Y') as well as Azimuthal Angle can be retrieved from the curve.
Therefore, move the mouse pointer over the M² curve. As soon as it hits a
measurement point, it's shape changes to .
Then click to this point. In the Calculations to Actual Z Position panel will appear the
position according to the clicked point and the calculated values.