KAGRA MIR (Absorption)
MarcoBazzan - 19:54, Monday 04 February 2019 (1201)
Sapphire Namiki 1inch x 20mm
Members: Marco Bazzan, Manuel

P=32mW
We aligned the red probe with the surface reference sample.
Then we calibrated the bulk absorption.
Ac= 0.1V; DC=4.75V. T_ref=55%
R=0.1/4.75/0.032/sqrt(0.55)/1.04=0.85 cm/W

at 17:45 - Mounted the Namiki sapphire sample
Imaging unit position corrected for sample thickness by Delta_z = 8.6 mm
Rised the power to 1 W by rotating the IPC HWP
T_sapp=86%

Although noisy, we can observe an absorption profile by scanning the sample along z (see first screenshot). The profile is confirmed by flipping the sample (see second screenshot).

AC max = 250uV
DC=5V
Max absorption level estimate:

250/5/1/sqrt(0.86)/R*3.34 = 212 ppm/cm

Images attached to this report
1201_20190204115233_2019020413.png 1201_20190204115244_2019020414.png
Comments related to this report
MarcoBazzan - 16:55, Monday 18 February 2019 (1220)
After this measurements, the power was rised to 10.6 W on the sample and a set of measurements wee performed (scan XZ, YZ, XY top, XY bottom).