Ptychography and related diffractive imaging methods

Ptychography and related diffractive imaging methods are discussed. Most of the progress made in the early 1990s with the Wigner distribution deconvolution (WDDC) and Bragg-Brentano methods derived from the fact that the access to a dedicated network of high-powered workstations was present, all of which were equipped with graphical interfaces. Aside from computers, the two most important experimental issues that affect ptychography relate to the degree of coherence in the illuminating beam and the detector efficiency and dynamic range. Ptychography may be extended to 3D imaging via conventional tomographic techniques, and a key advantage of this technique is that it is not subject to the usual limitations of the coherence envelope and hence there is no limit to the resolution of ptychography other than the wavelength.