As reported in entry 2817 we can see vertical stripes in our measurements.

One question is are they correlated to the Y (horizontal) position of the mirror.

For reference, the measurement are done in zig-zag  ie we scan in X (vertical) and shift in Y.

I show in the attached figures the sum of the normalized s and p polarizations for various input polarization angles as a function of time.

The color changes correspond to a change in Y position.

To my eye it seems that these figures show that there is no clear correlations between the Y positions of the mirror and the power fluctuations.

In any case I will try to do further investigations next week.