Abstract
Independently of the type of source (visible light, X-rays, electrons) a microscope generally allows to produce enlarged images of the illuminated sample. In the most popular (optical or electron) microscopy techniques, this results in the direct imaging of the investigated sample or a portion of it. As a consequence, all the observed details in the image are assumed to represent actual structures of the sample. In contrast, diffraction-based microscopy provides indirect (Fourier space) images of the sample, so that retrieving sample structure is in general not straightforward, but important, highlydetailed information (e.g., atomic structure) can be obtained, depending on radiation wavelength.