Work

Monolithic focused reference beam X-ray holography

Year: 2014

Type: article

Abstract: 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. There is a trade-off between image contrast and spatial resolution in Fourier transform holography, which limits its application in single-shot X-ray imaging. Here Geilhufe et al. use a Fresnel zone plate to decouple these two factors, which improves the efficiency of high-resolution holography imaging.

Source: Nature Communications

DOI: 10.1038/ncomms4008