In order to investigate the reason of the seemingly uniform theta distribution, we decided to start new measurements with the AZTEC sample rotated.

I marked the position of the holder, rotated the sample and measured an arc length of 3 cm that corresponds to a rotation of the sample by 34.4 deg (radius is 5 cm).

I took several measurements that are reported in the attached figures.

An important thing to notice is that I found I made mistakes in the use of the code.

Starting from the code available in the PC the modifications for our current setup are :

DC gain = 10

AC gain = 1000

DC is s - pol

AC is p pol

While the gain were correct, the previous figures were made with inverted AC and DC !

Also, the incident polarization angle was wrongly estimated (ie no normalization).

Note that to estimate the delta_n distribution it has to be multiplied by 1e6 to properly compute variance and mean.

Now all these modifications have been implemented for these figures.

Furthermore, the HWP working condition could be recovered a bit and all the reported measurements are made with the HWP between 341 deg ( s-pol) and 26 deg (p pol).

As a brief summary of the results :

- s0 and s1 absolute values are now similar

- delta n and theta increase with the incident polarization angle