= Some trial and errors =
[Yokozawa, Enomoto]

- damp the resonance of a mirror holder on POP table.
--> it seemed that we succeded to damp the resonance of one specific mirror holder, but we still see the struncture that is excited when we hit the mirror or its pedestal post.
This indicates that this structure comes from the resonance of optical post.

- vibration isolation of the fiber from POP table
--> no change in control signal spectrum observed

- coherence with signal of the accelerometer on POP table.
--> found coherence where ACC singal has spetral peaks