Tonight I rotated the sqz phase around the squeezing angle at various nonlinear gain. So far it is unclear that higher nonlinear gain (up to 3.6) degrades squeezing at a noticeable level. The best range we saw was done at NLG of 2.698 (118.2Mpc on the SENSMON_CAL_EFFECTIVE_RANGE_MPC, barely touching 120 on the control room BNS monitor). 118 Mpc was also achieved at NLG of 3.269 and 3.605. During the measurement I monitor Lee's DB monitor to make sure that NLG didn't degrade significantly. At 3.605 I didn't have a chance to continue to rotate the phase just to see if the range would get better or worse before the lockloss. Dan will be posting about that. During the lockloss I was simply waiting for the BNS range to integrate. Nothing was adjusted. The OPO gain was compensated for the higher pump input.

I set the pump power at 0.77 normalized transmission, this gives nonlinear gain of 2.766, as close as I could get to the best measurement seen on BNS range. The phase is set to 110deg.

The start time of this measurement was 06:02:38UTC (reference time), end time was 08:18:31UTC. The next quick thing to do is to reduce the CLF power just to see if it changes squeezing.