Calibration check before measuring TAMA size sapphire

[Matteo, Simon]

Activity of 09/06:
We removed spare ETMY substrate and applied first contact on the surface we didn't clean before.
We checked the calibration (figure 1 and 2) before installing TAMA size sapphire and measure the absorption.

R_surf = AC_surfref/(DC_surfref*P_in*abs_surfref) = 16.9 [1/W]
where AC_surfref = 0.40V, DC_surfref = 3.85V, P_in = 0.028W and abs_surfref = 0.22

R_bulk = AC_bulkref/(DC_bulkref*sqrt(T_bulkref)*P_in*abs_bulkref) = 0.797 [cm/W]
where AC_bulkref = 0.08V, DC_bulkref = 4.65V, T_bulkref = 0.55, P_in = 0.028W and abs_bulkref = 1.04/cm

We then moved the translation stage of the imaging unit to take into account the thickness of the TAMA size sample (60mm) from 70mm to 44.3mm.

Reminder: dL_IU = (n-1)*L_sample / n

After calibration and installation we checked the XY limits of the translation stage and modified the X one to take into account the size difference with respect to KAGRA size mirrors (IMPORTANT: change them to go back to KAGRA size).
The coordinates of the center of the sample are: [X_c, Y_c] = [327.75, 123.25]

Then we did a series of z scan to determine the z position of input and output surface. Fig 3 shows the last one performed with 10.1W of input power.
According to the phase profile the input and output surface are at Z = [44, 79]