4.
Alignment and Measurement
4.6.
Error Sources of an Autocorrelation Measurement
4.6.1.
Scan Range too small or too wide
The
scout
Link
Control Software detects several error sources of the signal that could lead to im-
precise measurement of the laser pulse width. If such a limitation of the measurement is detected
the critical parameter or relevant error message is displayed in the info box of the measurement
window.
The following critical parameters are detected by the software:
Scan range too low:
If the chosen scan range is too low with respect to the detected width of the autocorrelation trace,
a part of the measured autocorrelation might be clipped. Without a robust determination of the
signal offset the evaluation of the total height of the maximum intensity is not possible. In order
to determine the FWHM value precisely the maximum as well as the minimum of the ACF must be
within the measurement window. If the minimum of the ACF is cut (see Figure 4.16) the calculated
FWHM value will be wrong.
Figure 4.16.: If the Scan Range is too low a warning is displayed in the Info box
Action: Increase the scan range!
Pulse
Scout2 Version 1.1
36
July 2015
