Figure 3
(a) Displacement spectral density as a function of the piezo driving voltage VD. Each curve lies on the plane identified by the gray line on the base floor, starting from its relative VD. The sidepeaks ~45 Hz aside of the main peak in the blue curve come from environmental noise which couples to the vacuum system. (b) Extracted total rms displacement of the membrane Δx as function of the piezo driving voltage VD. (c) Displacement spectral density resulting from the thermal fluctuations of the membrane.
