Michael and Yuhang

To check the stability of detuning with stable cavity axis, GR AA and GR pointing, we decide to perform FDS measurement. To better resolve the whole rotation part of squeezing, we detuned filter cavity by 200Hz to avoid back scattered noise contamination.

The measurement result is in the attached figure. We can see the detuning fluctuation is about 10Hz from this measurement.

We still miss the homodyne angle around 90deg, we should take it soon.