Modeling the mode cleaner as a simple cavity with all losses lumped together, we expect the cavity power to be
attenuated by a factor (1-L) after each interval (2l/c)=1/fsr. Therefore we can get the cavity loss L
(including power lost through transmission) from the ringdown time constant tau as:
L = 1 - exp[ - 1/(tau * fsr) ]
From this we have to subtract the 2000 ppm transmission for each of MC1 and MC3, and divide by three to spread
the losses across the three optics.
I get **168 ± 39 ppm** loss per optic based on a very simple exponential fit to the tails (t>0) of four of Andrey's data files.
By comparison, I get **154 ± 37 ppm** from Rana's data files from before the vent. |