Attached all the in-loop squeezer noise measurements prior to PSL TTFSS fix with all the transfer functions and the common mode board settings at time. Note that the more recent CLF and LO data should be refered to Vicky's alog66884. The calibrations and UGFs are as follow:

TTFSS loop (fast path only, no EOM): 16 kHz UGF, 0.6 rad/V

SHG loop: 1 kHz UGF, 1.26e-8 V/Hz --> Note that this UGF is quite high compared to the past (200 Hz UGF). Make sure that SHG is not injecting any mechanical noise to CLF.

OPO loop: 2kHz UGF, 5.8e-7 V/Hz --> I had a hard time fitting this loop properly but since calibration is all I needed it should be good enough for now. Spectrum looks peaky. 4kHz pole filter was one (I don't think we used it before).

CLF loop: 1.4 kHz UGF, 0.05 V/rad --> At the time CLF didn't have any boosts on. See attached screenshot. Two boosts should have been on.

LO loop: 1.6 kHz UGF, 0.2 V/rad --> Only one boost was on at the time. Should have been two. 

FC green: 2.6 kHz UGF, 1e-4 V/Hz --> We used to be able to push this to 10kHz UGF.

All the optimized settings from O3 can be found here. I also added SK measurements made a day before to see how it compared.