Took another data set of FIS with different SRCL offsets, to try to set the SRCL detuning for calibration measurement, similar to 79903.
- no squeezing: 1411485337 (120 seconds) (ref 4)
- FIS, ran scan alignment, ressults here , ran scan sqz ang with the blrms changed to 6 (we normally use 3, to minimize the 300 Hz noise, but in this case we want to min 1.7kHz sqz) SRCL at -290 start at 1411486541 ref 5 (SRCL offset we have been observing with)
- FIS, SRCL at -190 start at 1411487041 ref 6
- FIS, SRCL at -90 start at 1411487385 ref 7
- FIS, SRCL at -340 start at 1411487954 ref 8 (manual sqz ang adjust)
- FIS, SRCL at -390 start at 1411488251 ref 9
- FIS SRCL at -490 start at 1411488585 ref10 (22.2k counts on POP A 45I ADC)
Here are some plots of this code, made by borrowing heavily from Vicky's repo here and from the Noise budget repo. I will put this into a repo soon, perhaps here.
The first plot shows the spectra with different SRCL offsets in, always with the squeezing angle optimized for kHz squeezing. The no squeezing model isn't well verified, I've used SRCL detuning of 0 which we know isn't correct. We use this no squeezing model to subtract from the no squeezing measurement to estimate the non-quatum noise, shown in gray here. The SRC detuning doesn't change this estimate much without squeezing injected.
The next plot is a re-creation of Vicky's brontosaurus plot, as in 79951. The non-quantum noise estimate is subtracted from each of the FIS curves, which are then plotted in dB relative to the no squeezing model. Each of those shows a squeezing data set with a model, where I by hand adjusted the SRCL offset in the model based on this plot. The subtraction is needed to make the impact of the SRCL offset clear.
The final plot shows the linear fit of the SRC detuning to SRCL offset, which gives us the SRCL offset we should use to go toward 0 detuning, (-191 counts).
