BIGFOOT (Cavity)
MarcEisenmann - 14:03, Thursday 09 March 2023 (3200)
LC characterization (2)

[Marc, Rishabh, Shalika]

We first tried to rotate the LC while monitoring both azimuth and ellipticity.

It seems that we have a minimum azimuth angle of 2deg..

We changed the mounts of QWP and HWP for motorized ones.

By rotating the HWP we can now bring back the azimuth angle after the LC to 0deg...

It is not clear to me how this can happen..

We acquired some sweep in this condition but found similar levels of retardation.

Then, we installed and aligned a PBS before our camera to acquire data in the crossed polarizers technique.

FInally we heated the LC to about 40deg and acquire data with 0Vrms applied while letting cool down to about 25deg as shown in figure 1.

We have to add input power monitor to get more precise estimation.

Images attached to this report
3200_20230309060323_pvstv0.png