We have two sapphire samples with the dimensions of Tama mirrors.

To measure them,  I fixed a horizontal translation stage at the optical board and placed the mirror mount on top of it.

The first Idea was to make a scan by moving the translation stage manually (by using its micrometer screw) and taking a measurement every 5mm.

Then I realized that I could replace the micrometer screw with one of the 3 step motors of the XYZ translation stage of the PCI system, and doing so, I could make an automatized scan of the samples with the original software of the PCI system.

Before making the measurements I made a calibration scan of the bulk reference and found the usual value R=0.5W^-1. This value is for silica, to use this calibration for sapphire samples we have to add a factor of 3.34. This correction factor was provided by the SPTS company (Alexandrovski)

The position of the Imaging Unit is corrected by 25.9mm according to the formula SampleThickness*(n-1)/n   elog entry 294

I manually moved the tama sapphire sample in order to have the pump at the center of the sample. 

The scan gives a good SNR and the result is 50ppm/cm for both the samples with some zone with higher absorption.