Soft x-ray holographic microscopy

Abstract

We present a new x-ray microscopy technique based on Fourier transform holography FTH, where the sample is separate from the optics part of the setup. The sample can be shifted with respect to the holography optics, thus large-scale or randomly distributed objects become accessible. As this extends FTH into a true microscopy technique, we call it x-ray holographic microscopy XHM. FTH allows nanoscale imaging without the need for nanometer-size beams. Simple Fourier transform yields an unambiguous image reconstruction. We demonstrate XHM by studying the magnetic domain evolution of a Co/Pt multilayer film as function of locally varied iron overlayer thickness.

Development of Scanning-Type X-ray Fourier Transform Holography

“…Figure 3(e) shows the magnetic domain image in an 8 µm × 2 µm area, which was obtained by combining the seven images measured at each position. Recently, similar results have been reported using a circular-shaped window [7]. This result indicates the method does not depend on the window shape.…”

Magnetic states in low-pinning high-anisotropy material nanostructures suitable for dynamic imaging

“…The mask is aligned to the magnetic disk using piezo stages. 34 This approach requires a special image reconstruction procedure to achieve optimal spatial resolution due to the finite distance between sample and mask (11 μm in our case). 35 The holographic imaging was performed at the UE-52 SGM beamline at the BESSY II synchrotron in Berlin using circularly polarized photons with energy tuned to the Co L 3 absorption edge (778 eV), employing XMCD to obtain magnetic contrast.…”

Exploring the limits of soft x-ray magnetic holography: Imaging magnetization reversal of buried interfaces (invited)

“…26 In this case, all holography-optical elements are separated from the magnetic sample and are moveable with respect to the sample, allowing to explore different areas over the sample. Better spatial resolution can actually be achieved by using smaller reference holes with iterative phase retrieval methods 10 and/or extended references by using the HERALDO (holography with extended reference by autocorrelation linear differential operation) concept.…”