[Eleonora, Matteo L.]

In order to investigate the fluctuations of the IR reflected power during the lock-unlock measurement, we have plotted the histogram of the data both for a lock and for an unlocked period. 

We observe that for the unlocked period the noise seems to be gaussian as we expected assuming that it is domated by input power fluctuations.

On the other hand the fluctuations during the locked period dosen't seem to be gaussian and shows a "longer tail' on the right side. This is compatible with fact that the mechanisms explaining such fluctuations (in addition to the input power one), that is misalignments and lock accuracy, are expected to act only increasing the reflected power.

We don't know which is the best distrution to use to fit the locked data. Up to now they have been treated as if they were gaussian.

The last plot shows the contour of the normalized histogram for different set of lock/unlock taken during the same measurement.