[Marc, Michael]

To prepare the shipping of the AOM function generator back to APC, we installed our new one (WF1968).

We used same settings as before (continuous mode, freqeuncy = 109.036035615 MHz, 1.124Vpk=5dBm).

We had quite low green power after the IRIS after the AOM.

Power budget was :

SHG reflection ~270mW

before AOM ~41.2mW

after AOM ~37.6 mW

after iris ~5.7mW

before FC ~5.26 mW.

We tuned a bit the steering mirror between the AOM and iris. Especially, there seemed to be a little clipping in the vertical direction but it did not help to recover the usual power.

We checked the function generator output on spectrum analyzer and found a -3.28 dBm amplitude. Therefore, we increased the amplitude to recover the usual 5dBM : 2.95VPk gives 5.1 dBm.

In this configuration we recovered the usual AOM transmission.

We had to realign the last steering mirror on the bench to recover the PR targets.

The beam was then really far of the BS target. We tried to move PR mirror bu it did not seem to move. The health check has some error message ('No measurement channel defined') that we need to investigate.