Pengbo, Simon

Today, the upgrading process was continued by setting everything except the FI in its determined position, according to the draft which is attached to this report.
As for a matter of understanding, this draft is a supposed to be a first trial of the basic working principle which we are aiming for.

By re-activating the laser, I recognized that if the first PBS is set plane in its position as indicated in the draft, only a few percent of power would be P-polarized. Therefore, I rotated the PBS so that the non-used beam would be weakest. With this, I planted a beam-dump on top of the PBS cube (thanks to Thorlabs cage system) to catch that beam. In my opinion, even with this a little bit strange setup, security is maintained. In a next step, the motorized HWP was tested with the laser and confirmed to be working fine.

Addendum: I set also a beam-dump on the second PBS to cover the non-used S-polarization.