I was wondering about the high frequency noise coupling to DARM, and whether that could be frequency noise on the sidebands being transmitted through the OMC.
The sidebands are suspect because they do not see the coupled cavity filtering, and the Freq to DARM coupling is flat out to high frequency.
Sheila suggested I change the RF sideband amplitudes to see if the coupling changes.

When we increase the sideband amplitudes, the Freq Noise to DARM TF slightly decreases, and vise versa.
This seems to be consistent with the carrier being the bearer of frequency noise to DARM coupling.  Moving the sidebands also changes the light in the carrier, so we have less sidebands -> more carrier light -> slightly more freq to DARM coupling.


For the frequency noise injection, I injected into the Common Servo Board EXC A a cheby1 bandpass from 1 to 7 kHz with gain of 0.1.
I then moved the 9 and 45 MHz up and down by +3 dB.  "Nominal" sidebands in the plot refers to 24 dB on the RF AM slider for 9 MHz, and 20.4 dB for 45 MHz.
It seems like moving the 45 MHz had more of an effect on the Freq to DARM coupling than moving the 9.  

Data is in /ligo/home/craig.cahillane/Git/IFO/DARM/data/FreqInjWithSidebandsChange.xml