Waveguide-Based Off-Axis Holography with Hard X Rays

Abstract

We present an off-axis holography experiment based on the coherent cone beams emitted from a pair of x-ray waveguides. A magnified off-axis hologram is recorded, from which the phase of the optical transmission function of a sample is obtained by digital holographic reconstruction. A spatial resolution of about 100 nm has been achieved at 10.4 keV photon energy. Spatial resolution is determined by the cross-sectional dimensions of the waveguide and could approach a fundamental limit of about 10 nm in future experiments. In addition, we propose a new experimental setup that might overcome this limitation.

Coherent X-ray diffractive imaging on the single-cell-level of microbial samples

“…X-ray waveguides [209,228] are optical elements for preparing quasi point-sources with sizes well below 100 nm in the hard X-ray regime [147,165,221]. Due to the ltering of the coupled X-rays by propagation through the waveguide [91,222], the prepared quasi X-ray point source is ideally suited for X-ray imaging in the holographic regime [89,165]. In addition, the waveguide source can also be used for iterative phase retrieval of isolated biological specimens in two and three dimensions [12 14] by taking advantage of robust phase retrieval in the Fresnel regime [94,241,334,335].…”

Advances in fabrication of X-ray waveguides

“…The curvature (radius R = 200 mm) of the WG leads to a deflection of 0.6 • with respect to the primary beam, which is indicated by an arrow. Using curved or slightly inclined elements, two beams can be separated [36] or one beam can be split into sub-beams [33].…”

Two-dimensional X-ray waveguides: fabrication by wafer-bonding process and characterization

“…The Y-shaped waveguides consist of a pair of two lines which are close together at the front side, but which diverge towards the exit side of the waveguide chip. Y-shaped waveguides can be used to split up the incoming beam for off-axis (reference-beam) holography [18]. The exposed resist was developed in a 4 : 1 mixture of ethyleneglycolmonoethylether (8.01554, MERCK) and ethyleneglycolmonobutylether (8.00857, MERCK) (Fig.…”