Abe, Marc, Yuhang

cleaning

We removed #4 from translation stage.

We inspected the optics with strong flashlight and green lights and the 'clean room' is now really dirty...

We decided to clean #3 before birefringence measurement (first surface cleaned and second should be dry tomorrow morning).

After the scattering measurement of #1, we applied first contact on one surface and will apply it on the second surface tomorrow before moving it to ATC for the TWE measurements.

measurement preparation

We installed the 2 razor blades on the translation stage and measured their position wrt to the last steering mirror on the injection bench (153 mm for vertical and 177 mm for horizontal).

We wanted to measure the beam position with laser diode current of 6 A and rotating the HWP to reduce the power but the beam shape became terrible (kind of 2 blobs)

We decreased the laser diode current to 1A and rotated the HWP to recover the same power as before.

The beam shape became reasonable again which means that we can proceed with briefringence measurements but need some investigation before being able to start absorption measurements.

We measured the beam position on the last steering mirror and tweaked the pitch/yaw of this mirror to have 0.049 deg AOI  in vertical and -0.072 deg AOI in horizontal (see attached figures).

Tomorrow we will do calibration and start birefringence measurements.