Intensity stabilization performances

I checked the performances of the ISS on the two benches.

NI bench: the loop is doing fine with respect to the open loop noise, but it is still far from the PD dark noise. We should understand the reasons. There is still margin for improvement of about a factor of 2. Blue is the dark noise, black is the closed loop noise spectrum and purple is open loop.



WI bench: I did not plot the open loop noise, but from the picture it is clear that we are dark noise limited!!! Purple is dark noise and black is closed loop.