Multi-mode laser detection

[dnadlinger]

Since the DL pros usually don't tend to go multimode on their own, it might take a while to notice when they in fact are – especially when using the wavemeter inteferometer spectra instead of a separate OSA, as they are visually more crowded.

Integrating an algorithm to detect this from the wavemeter CCD images and flag the issue to the user (yellow stripes in the UI background, status queryable via the RPC interface) might be useful. From my own experience, this is definitely possible by eye after staring at the HighFinesse software for long enough, at least for lasers that are grossly multi-mode.

There was some work on this at ETH, though I haven't heard any news as to how well this works in practice: https://ethz.ch/content/dam/ethz/special-interest/phys/quantum-electronics/tiqi-dam/documents/masters_theses/Masterthesis_C%C3%A9dric_Huber