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Message ID: 149     Entry time: Fri Apr 8 03:54:39 2022
Author: Patrick 
Category: Laser 
Subject: Q-switch window 
The solution of increasing the Q-switch window from 2us to 5us described in ID:148 fulfills its purpose, but the window is unstable.
We saw the laser jumping across the screen which was because the Laser had a lot of hickups.
The hickups come from the signal which determines the duration of the window.
This window "flickers". It gets very small, leaving no time for coincident events which fire the laser.
This is probably an issue with the NIM module.
Compare the picture below: The oscilloscope freezes and only the first of the yellow pulses is visible which should repeat and span 5us at the moment.

After looking at the different signals to trigger the laser on the oscilloscope, the laser does not fire anymore when used in the external trigger mode.
However, all signals are looking good and everything should be in the same state as before.
The internal Q-switch works as good as before.
Attachment 1: 2022-04-08_Q-switch_window.jpg  390 kB  Uploaded Fri Apr 8 06:27:37 2022  | Show | Show all
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