Using the delay line setup with a digital PID slow control on the Moku:Pro in multi-instrument mode, I first calibrated the delay line by offset locking and measuring the beat frequency with small offsets, and then measured the noise spectra at the delay line with no offset. The script I used to analysze the results is here.

Then I ran the noise calibration script and plotted this instead of the previously measured data [Attachment 1].

Attachment 2 contains a comparison of the old and new laser noises measured with the North-South beat. The north laser is still powered by the ITC510 which probably is why the forest of peaks still exist.