Monolithic focused reference beam x-ray holography

Fourier transform holography is a highly efficient and robust imaging method, suitable for single-shot imaging at coherent X-ray sources. In its common implementation, the image contrast is limited by the reference signal generated by a small pinhole aperture. Increased pinhole diameters improve the signal, whereas the resolution is diminished. Here we report a new concept to decouple the spatial resolution from the image contrast by employing a Fresnel zone plate to provide the reference beam. Superimposed on-axis images of distinct foci are separated with a novel algorithm. Our method is insensitive to mechanical drift or vibrations and allows for long integration times common at low-flux facilities like high harmonic generation sources. The application of monolithic focused reference beams improves the efficiency of high-resolution X-ray Fourier transform holography beyond all present approaches and paves the path towards sub-10 nm single-shot X-ray imaging

Soft x ray tomoholography

We demonstrate an x ray imaging method that combines Fourier transform holography with tomography tomoholography for threedimensional 3D microscopic imaging. A 3D image of a diatom shell with a spatial resolution of 140 nm is presented. The experiment is realized by using a small gold sphere as the reference wave source for holographic imaging. This setup allows us to rotate the sample and to collect a number of 2D projections for tomograph

Biotechnologie 2000 - Biotechnologische Herstellung von Spinnenseiden. Teilprojekt: Klonierung und rekombinante Expression von Spinnenseidenproteinen als Ausgangsmaterial fuer die technische Herstellung von Spinnenseiden Schlussbericht

Available from TIB Hannover: DtF QN1(80,11) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEBundesministerium fuer Bildung und Forschung (BMBF), Bonn (Germany)DEGerman

Extracting depth information of 3 dimensional structures from a single view X ray Fourier transform hologram

We demonstrate how information about the three dimensional structure of an object can be extracted from a single Fourier transform X ray hologram. In contrast to lens based 3D imaging approaches that provide depth information of a specimen utilizing several images from different angles or via adjusting the focus to different depths, our method capitalizes on the use of the holographically encoded phase and amplitude information of the object amp; x2019;s wavefield. It enables single shot measurements of 3D objects at coherent X ray sources. As the ratio of longitudinal resolution over transverse resolution scales proportional to the diameter of the reference beam aperture over the X ray wavelength, we expect the approach to be particularly useful in the extreme ultraviolet and soft X ray regim

Method for Single Shot Coherent Diffractive Imaging of Magnetic Domains

In preparation for real space studies of magnetic domains in a pump probe setup at free electron laser sources, it is necessary to develop an imaging method compatible with the linearly polarized radiation available at these sources. We present results from a prototype experiment performed at the synchrotron source BESSY II, using a modification of existing phase retrieval techniques. Our results show that it is possible to image magnetic domains in real space using linear polarized light, and we introduce the concept of a reliability map of our reconstructions using Gabor transform

Influence of stray fields on the switching-field distribution for bit-patterned media based on pre-patterned substrates

Équipe 101 : Nanomagnétisme et électronique de spinInternational audienceUsing a direct imaging method, we experimentally investigate the reversal of magnetic islands in a bit-patterned media sample based on a pre-patterned substrate. Due to systematic variation of the island distances in the media, we are able to study the influence of the dipolar interaction on the switching-field distribution of the island ensemble. The experimental findings are explained by an analytical magnetostatic model that allows us to quantify the different components of the demagnetizing field in the system and to distinguish intrinsic and dipolar broadening of the switching-field distribution. Besides the well-known dipolar broadening due to stray fields from neighboring islands, we find strong influence from the magnetized trench material on the island switching

Monolithic focused reference beam X ray holography

Fourier transform holography is a highly efficient and robust imaging method, suitable for single shot imaging at coherent X ray sources. In its common implementation, the image contrast is limited by the reference signal generated by a small pinhole aperture. Increased pinhole diameters improve the signal, whereas the resolution is diminished. Here we report a new concept to decouple the spatial resolution from the image contrast by employing a Fresnel zone plate to provide the reference beam. Superimposed on axis images of distinct foci are separated with a novel algorithm. Our method is insensitive to mechanical drift or vibrations and allows for long integration times common at low flux facilities like high harmonic generation sources. The application of monolithic focused reference beams improves the efficiency of high resolution X ray Fourier transform holography beyond all present approaches and paves the path towards sub 10[thinsp]nm single shot X ray imagin