When zooming in to perform a ringdown measurement I found a ~200 MHz oscillation in the TRANS signal. This is OFC2 TRANS. The oscillation frequency corresponds exactly to the opposite AOM's frequency. Previously we had observed a beatnote between the two AOM frequencies, and could be solved by tuning the AOM frequencies to be more than 2 ish MHz away from each other. 

Now we are seeing a 200 MHz signal regardless of the relative frequency. Changing the other AOM frequency changes this oscillation directly. I don't think this is optical, and is purely an electrical pick up. Just making a note of this to be seen on the log book for the future. Also this is a one way problem, OFC2 sees AOM1 but OFC1 does not see AOM2.