Marc, Matteo

We removed the AZTEC #5 from the translation stage and installed 2 razor blades.

They are at 120 mm (for the vertical cut) and 122 mm (for the horizontal cut) of the last steering mirror on the injection path.

We realigned the probe beam and reached 0.003 deg and 0.005 deg angle of incidence for vertical and horizontal respectively.

We realigned the PBS and our photodetectors, tuned the QWP and HWP.

S polarization is best for 3.1 deg of the HWP. The best p polarization is reached by moving the HWP angle by -45 deg.

We did the calibration as for #3.

A bit strange result was that s and p polarization power fluctuations were anti-correlated suggesting that the input polarization was fluctuating.

Touching a bit the laser fiber I could generate such anti-correlation. One possible explanation for this could be that the fiber is now touching/resting on the scattering black box foil which might be moving due to the air flow (?).

In any case, we could get some reasonable calibration factors but we will further investigate this issue.

Finally, we started polarization measurement with s polarization at the input.