Something like a sensitivity.

Sum of red and blue curves in Fig.1 is roughly estimated sensitivity in-air FPMI with AS17.
Now only TM is taken into account, so the sensitivity below 30Hz is not so accurately due to the effect of IM (and MN).

Brown curve represents a dark noise at AS PD measured today.
ADC noise should be ~1e-17m/rHz @10Hz which is lower than the measured noise on AS PD channel, because two z1;p10 whitening filter are now enabled.
1e-17m/rHz = 1e-6[V/rHz] / 610[uV/ct] * -234dB(AS17Q filter bank) / 2.6(laser power norm) * -0.8(lsc input matrix) / 100(whitening gain above 10Hz)

Black curve shows a FPMI sensitivity when we achieved 1.3kpc during O3 commissioning reported as klog#10869.