We measured AZTEC #1 polarization with 0 deg (or s polarization), 15 and 45 deg polarization angle at the injection (see figures 1 to 3).

From the measurements with 0 and 45 deg input polarization angle, I could compute delta n and theta (figure 4) and s to p polarization losses (figure 5).

From this last figure, we can see a good agreement of losses between the direct measurement with the computation from delta n and theta.

This was not the case for the measurement with 15 deg input polarization angle and investigation are on-going.

The bad news is that theta is not uniform inside the central area of the mirror. This means that there is no rotation of the sample that will decrease the s to p polarization losses inside this area.