I'm scanning the sample along the beam direction. I placed a translation stage with a micrometric screw below the mirror mount and set the sample height so that the pump goes at the centre of the sample.
Pictures 1,2,3 show how it was before.
Pictures 4,5 show the current setup.
I'm doing one measurement for each 5 mm of sample depth.
In the following table, there is a summary of last measurements
| raw data | filtered data | |||
| depth |
absorption ppm/cm |
precision ppm/cm |
absorption ppm/cm |
precision ppm/cm |
| 0mm | 13.0 | 7.2 | 12.9 | 1.7 |
| 5mm | 12.4 | 7.3 | 12.3 | 1.6 |
| 10mm | 6.8 | 7.4 | 6.8 | 1.2 |
| 15mm | 9.8 | 8.6 | 9.7 | 1.3 |
| 20mm | 9.3 | 7.9 | 9.3 | 1.1 |
| 25mm | 9.0 | 8.3 | 8.9 | 1.3 |
| 30mm | 7.5 | 6.4 | 7.5 | 0.9 |
"Depth" is the position of the incident sample surface with respect to the pump-probe cross point. According to the refraction effect, the cross point position inside the sample is double, so, given the sample thickness 60mm, the depth 30mm refers to the measurement at the opposite surface of the sample.
I attach the plots of the 6 sets of measurements.