Diffractive X-ray Lenses

X-rays are used in a wide range of experiments to investigate the structure of matter. They give the ability to penetrate comparatively thick samples, and give information on the elemental and even chemical composition. Moreover, and the short wavelength carries the potential of excellent spatial resolution down to the atomic scale. In practice, the spatial resolution of x-ray probes and x-ray microscopes are limited by the quality of the available x-ray optics.
The X-Ray Optics and Applications group is applying micro- and nanofabrication techniques to fabricate diffractive x-ray lenses, i.e. Fresnel zone plates. The resolution of Fresnel zone plates is limited to the width of the outermost zone drN. Therefore, we use high-resolution electron-beam lithography to write the zone plate pattern. The pattern must be transferred into suitable materials to provide sufficient absorption or phase shift for the x-rays in order to achieve good diffraction efficiencies. Especially for high photon energies this results in the challenge to produce nanostructures with extreme aspect ratios, i.e., with heights that are much bigger than the width.

The X-Ray Optics and Applications group is specialized on pushing the limits of diffractive x-ray optics, regarding resolution and efficiency. We collaborate with many research groups at synchrotron end stations to provide optimized, custom-made devices for optimum performance, covering a wide photon energy range from below 100 eV to beyond 10 keV. Moreover we develop novel optical schemes and application areas, such as advanced Zernike phase contrast imaging, coherent diffraction imaging, or devices for experiments at X-FEL sources.

Current Research on Diffractive X-Ray Lenses

    • Electroplated Zone Plates and Beam Shapers
    • Ultra-high Resolution Zone Plates
    • Double-Sided Zone Plates
    • Blazed X-ray Optics
    • Zernike X-ray Phase Contrast Microscopy