To see the contribution of noise at different frequencies, I performed the coherence measurement between squeezing and GRMC locking loop error signal/IRMC locking loop error signal/GRMC transmission signal/Green phase-locking error signal/IR phase-locking error signal.

The result is attached. From these results, we could have the following deduction:

• GRMC locking loop is contributing the noise at 9.5kHz and 6.9kHz
• The coherence between 3.7kHz and 6.9kHz shows up mainly in IR phase and IRMC locking.
• It seems IR phase noise and IRMC locking loop has strong coherence. So I think we can improve IR phase behavior by improving IRMC locking.
• 600Hz noise doesn't show up in the IRMC and GRMC locking loop.
• Sometimes, the squeezing measurement is very good. For example, the one together with GRMC loop error signal. I attach the squeezing level at that time.

All the measurement is using averaging of the meachine of 200, I think we should use more average in the future.