[Aritomi, Yuhang]
Today we found that FC green error signal was noisy due to SHG oscillation. The figure 1 and 2 show the FC error signal with SHG gain of 1.4 and 1.6. We decreased the SHG gain from 1.6 to 1.4. The SHG OLTF with gain of 1.4 is shown in figure 3. The UGF is 4.7 kHz and phase margin is 10 deg.
We also found that the FC green injection power was reduced. We changed the SHG temperature and the green injection power increased from 18.8 mW to 23.7 mW.