TY  - JOUR
A1  - Pietsch, Ullrich
A1  - Jarre, A.
A1  - Salditt, T.
A1  - Panzner, Tobias
A1  - Pfeiffer, F.
T1  - White beam x-ray waveguide optics
N2  - We report a white beam x-ray waveguide (WG) experiment. A resonant beam coupler x-ray waveguide (RBC) is used simultaneously as a broad bandpass (or multibandpass) monochromator and as a beam compressor. We show that, depending on the geometrical properties of the WG, the exiting beam consists of a defined number of wavelengths which can be shifted by changing the angle of incidence of the white x-ray synchrotron beam. The characteristic far-field pattern is recorded as a function of exit angle and energy. This x-ray optical setup may be used to enhance the intensity of coherent x-ray WG beams since the full energetic acceptance of the WG mode is transmitted. (C) 2004 American Institute of Physics
Y1  - 2004
ER  - 
TY  - JOUR
A1  - Giewekemeyer, K.
A1  - Krueger, S. P.
A1  - Kalbfleisch, S.
A1  - Bartels, Meike
A1  - Beta, Carsten
A1  - Salditt, T.
T1  - X-ray propagation microscopy of biological cells using waveguides as a quasipoint source
JF  - Physical review : A, Atomic, molecular, and optical physics
N2  - We have used x-ray waveguides as highly confining optical elements for nanoscale imaging of unstained biological cells using the simple geometry of in-line holography. The well-known twin-image problem is effectively circumvented by a simple and fast iterative reconstruction. The algorithm which combines elements of the classical Gerchberg-Saxton scheme and the hybrid-input-output algorithm is optimized for phase-contrast samples, well-justified for imaging of cells at multi-keV photon energies. The experimental scheme allows for a quantitative phase reconstruction from a single holographic image without detailed knowledge of the complex illumination function incident on the sample, as demonstrated for freeze-dried cells of the eukaryotic amoeba Dictyostelium discoideum. The accessible resolution range is explored by simulations, indicating that resolutions on the order of 20 nm are within reach applying illumination times on the order of minutes at present synchrotron sources.
Y1  - 2011
U6  - https://doi.org/10.1103/PhysRevA.83.023804
SN  - 1050-2947
VL  - 83
IS  - 2
PB  - American Physical Society
CY  - College Park
ER  -