Fig. 5. Mechanical performance of the microscope.

(Left) PSD of zone plate vibrations and sample drift (inset). The servo loop reduces mechanical drift but increases high-frequency vibrations slightly, while drift due to thermal effects is less than 2 nm/min. (Right) System bandwidth measurement of the new instrument and a conventional STXM design. The −1-dB oscillation amplitude is achieved at three times higher frequency, showing improved mechanical performance. The inset shows the step response for a 40-nm step, which is achieved in less than 10 ms.