Yuhang, Eleonora

Last week we re-measured FDS with the new Faraday isolator.

The cavity was very well aligned (both in IR and green), mirror motion was small, but we could not go below shot noise at low frequency.

The squeezing at high frequency is 2.5dB (1dB less than usual). We suspect the Faraday is introducing more losses than we expected(elog 2055).

The back scattering seems quite low but we suspect that this is due to the low motion of suspended mirrors and not to the FI. In fact, in a previous measurement we observed high back scattering also with the new Faraday isolator(elog 2069).