Aritomi, Marc

Today, after the last absorption measurement of the annealed AZTEC sample (entry to follow), we prepared the switch to birefringence measurement.

We decreased the pump laser power to about 0.1 W and installed the 2 blades on the translation stage.

We measured the distance between the blade and the last steering mirror as 17.3 cm and 18.1 cm for the horizontal and vertical one respectively.

We reinstalled the steering mirror just after the last lens on the pump beam.

To reach normal incidence of the pump beam our plan is to do some vertical/horizontal scans at various z positions (eg 20 60 and 120 mm) to check the position of the beam on the last steering mirror.

Then we place the razor blade at the furthest position (120 mm) at the vertical/horizontal position at the level of the last steering mirror.

After some back and forth we reached 0.024 deg and 0.003 deg incidence angle for horizontal and vertical.

We'll start the birefringence measurements tomorrow.