I've taken the above RIN data and combined it with the intensity-to-frequency TF in PSL:1316 to arrive at an estimate of the RIN-induced frequency noise.
By eye, I fitted the magnitude of the transfer function from Tara's farsi.m code to the following model:
The first attachment shows this fit compared to the original TF.
I used this TF (along with the dc power 0.74 mW incident on the cavity) to convert the measured RIN (suppressed and unsuppressed) into frequency noise. I multiplied the result by a fudge factor of 3 to account for the fact that the TF we measured was a factor of 3 higher than the expectation.
The result is shown in the second attachment. Since this only with *G* = 500, Chas's high-gain ISS board should crush the RIN well below the expected Brownian noise. |