Aritomi, Marc, Matteo, Simon

Yesterday, we started by aligning back the ir beam on the 2 lenses [ before I wasn't thinking about the fact that adjusting the beam position by acting on these lenses will introduce astigmatism...]

Then we used the pinhole to characterize the ir beam.

The beam waist was too far (~60mm) so we moved the first lens after the periscope closer to the periscope.

I discovered that previous fits were wrong because i was trying to fit at the same time beam waist [um] and position [mm]. I corrected this and results are presented in figure 1 (red is red beam, blue is ir).

The situation is :

- crossing position is roughly matched to the 2 beam waists

- ir waist roughly 2 times too large -> need to move the second lens after the periscope closer to the periscope by ~1mm

- ir beam is not horizontal -> higher than red beam (larger z corresponds to smaller height)