I modified the photo-thermal part of the NB to use the Alnis et. al. number of 25 Hz / uW  (frequency shift per input power noise). I adjusted it for the ratio of the cavity lengths between theirs and ours, and also for the ratio of the Finesses (400000 : 10000).

Tara should now grab this code and replace my guess at the RC RIN with his real measurements and also add the previously measured RC/AC frequency noise to this plot.

The punchline is that the this thermo-refractive noise is significant and we must control the low frequency RIN.