High Resolution X-ray Microscopy For Nano-Resolution Imaging

If an object is illuminated with coherent electromagnetic radiation, e.g. by visible laser light or highly brilliant X-rays, a diffraction pattern is formed in the Fraunhofer far field that is related via a Fourier transform to the optical transmission function of the object. The aim of X-ray diffractive imaging or so-called lensless imaging, is to directly reconstruct the original optical transmission function of the specimen from its measured diffraction pattern. In principle, it allows one to obtain a resolution that is ultimately limited only by the wavelength of the radiation used and not by the quality of optical lenses. In X-ray microscopy, for instance, the resolution is presently limited to several tens of nanometers because of difficulties in manufacturing efficient high-quality nano-structured X-ray optical elements. Since this technique allows the resolution to be increased beyond these limits, they are among the most promising techniques for X-ray imaging applications in life and materials sciences on the nanometer scale.