Abe, Aritomi, Marc

Because the 2 lenses positions on the ir path has been changed quite a lot, today we decided to scan the imaging unit position.

Results are presented in figure 1.

It seems that now the IU position that maximizes the surface calibration value is Z(IU) = 68 mm.

After finding this new position, we aligned really carefully the pump & probe beams and got R_surf = 17.9 [1/W].

Then, we replaced the surface calibration sample by the bulk sample.

We got R_bulk = 0.67 [cm/W]. A reason of small R_bulk could be that we were not maximizing the DC signal at exactly the center of the sample (?)