I have started to repeat the same noise measurements we made during HIFOY, in particular for the PLL loop (see alogs 9846 and 9251). So far I have made the following PLL measurements:

EY PLL OLTF: see alog 11180. The UGF is at 23kHz with a phase margin of 52 deg.

Beanote measurement: I measured the beatnote out of the direct monitor (-1dBm) of the pre-amplifier. Using the Agiliant spectrum anylzer, the signal strength was -20dBm at 39.62MHz with 100Hz BW. Notably, the medm screen reads back -5dBm which is after the +13dBm. The PLL BBPD DC readback was 2V with 17.8mW. I adjusted the calibration to 0.055A/W (different from at EX).

AG spectrum analyzer noise floor: I measured the noise floor of the spectrum analyzer to be at -122dBm at 100Hz BW.

BBPD dark noise: With the PD completely blocked, the noise was at -116dBm at 100Hz BW.

Shot noise: With only the fiber light blocked at the PD, the noise was at -108dBm at 100Hz BW.

PLL error signal: With the loop locked, I measured the error signal at the IMON of the PFD (i.e. this is a suppressed error signal). I have attached the data; measurements were taken with both the SR785 (EY_PLL_NoiseSpecV_Raw) and with the AG spectrum anaylzer (BBB2.txt) for high frequencies. I have also attached the concatenated data.