Figure 9.

Upper plots: histograms of the standard deviation (STD) and the width of the distribution containing 95% of the position values, determined from the interferometer data during a typical 2D ptychographic scan in the case of (a) the standard tomographic setup and (b) the ultrastable configuration. Lower plots: frequency spectra obtained from the same scans. For the ultrastable configuration, the resonance frequencies are reduced by about an order of magnitude, especially in the lower-frequency regime. The frequency spectra use the same arbitrary units on the ordinate.