Update

I included the 55 MHz sideband and higher order modes in my training examples. To keep things simple, I just assumed there are higher order modes up to n+m=4 in the input beam. The power in each HOM is randomly chosen from a random gaussian distribution with width determined from experimental cavity scans. I used a value of 0.913+-0.01 rad for the Gouy phase (again estimated from cavity scans, but in reasonable agreement with the nominal radius of curvature of ETMX)

Results are improved. The plot belows show the performance of the neural network on 100s of experimental data

For reference, the plots below show the performance of the same network on simulated data (that includes sensing noise but no higher order modes)