KAGRA MIR (Polarization)
MarcEisenmann - 21:05, Tuesday 05 October 2021 (2699)
Resetup of the imaging unit

Katsuki-san, Marc

After investigating the effect of the AZTEC sample rotation, we decided to try to act on the imaging unit part.

We removed the OD (2 and 3) in front of the PBS in the imaging unit and added similar OD in front of each PD.

We tried to tweak the alignment as best as we could but because we installed the OD with a quite large angle to try to mitigate effects of scattering we don't have a balance powers on the 2 PD.

In order to have a beam small enough on the PDs we had to replace the lens before the PBS by one from the FC Newport lens box (f = 125 mm)

Anyway we started measurement in this new configuration.