The ultrafast photodiode for SC-CC beat note detection was misalignment a couple of weeks ago, and the signal was not recovered from remote since then On Friday I found a faulty BNC adapter at the photodiode output. After replacing the adapter and manual alignment, the signal was back again, and I could engage the SC automatic alignment loop. Fig 1 shows a locking sequence - the SQZ_EQB1_HD_RF_DEMOD signal measures the SC-CC beat amplitude with a negative slope of -25 mV/dB. I tuned the axial position of the two lenses of the SC telescope to improve the beat amplitude (and thus the mode matching on OPA); when doing so, one of the actuators ran into saturation, see FIg 2. I left the AA loop engaged over night; during the nigth, the actuator recovered the linear range and the beat amplitude went back to the optimal value, see Fig 3 and Fig 4.

To measure the mode matching of SC on OPA:

1) I sent the beam on the SQZ_EQB1_IR_PD_MONI photodiode

2) I set the OPA In scanning mode, and I temporarily removed the BAB by acting on the BAB/2f actuated mirror in the AEI squeezer box.

The TEM00 reflection peak is about 360 mV, see Fig 5. The peaks of the three strongest HOMs are about 7 mV (i.e. 2% of the TEM00), 3 mV (i.e. 0.8% of the TEM00), and 2 mV (i.e. 0.5% of the TEM00), see Fig 6.