[Yuhang, Chien-Ming]

Today we tried to decrease CC laser power. But when we just decreased it to half, we couldn't lock the CC1 loop. 

The cc error signals that we can use to lock and cannot be used to lock are attached in Fig1.

The RMS dark noise for CC1 and CC2 PD is measured and attached in Fig2. We can see that the CC1 PD has RMS dark noise almost 5 times higher than CC2 PD. 

We also suspected that this noisy PD for CC1 locking brings also phase noise.