The TCS IFO mode simulation is running online and producing esimates for the round-trip Gouy phase of the SRC and PRC, the g-factors and HOM spacing of the X and Y arms. The assumed absorption in the optics is set to 250ppb per test mass but the arm power needs to be properly calibrated. However, when we see approximately 10mW of absorbed power in each of the test masses, we expect to see:

• SRC round-trip Gouy-phase shift from 24.6 degrees to 28.4
• PRC round-trip Gouy-phase shift from 19.9 degrees to 25.4
• HOM spacing in the arms shift by 40Hz