NAOJ GW Elog Logbook 3.2
[Eleonora.P, Eleonora.C, Pierre and, Yuhang]
Here I put some result about the noise performance of two positions. One is SHG transmission and the other is GRMC transmission.
I also measured the open loop transfer function of SHG again.
Figure 1: The new SHG servo shows an order of 2~10 larger noise above 1kHz.
Figure 2: New MZ servo reduces low frequency(100-1k) noise by a factor of 3~30. While the old servo reduces low frequency only a factor of 2~3. However, the new servo increases high frequency noise by a factor of ~1.2 while the old one reduce it by a factor of ~1.2
The measurement of old SHG OLTF shows very strange behavior. It has only unity gain frequency of 100Hz. There should be something wrong. But up to now, we didn't find out what is wrong.