**1. Introduction**

X-ray imaging is one of the work horses of modern science, at least since the availability of brilliant and coherent light at accelerator radiation sources of the third and fourth generation. X-ray imaging can yield excellent spatial resolution due to the short wavelength of the light and provides a great depth of information of the electronic state of the imaged specimen via spectroscopy. In addition, synchrotron X-ray photons typically come in short pulses, which facilitates time-resolved imaging. Manifold techniques exist for X-ray imaging, each with its merits and constraints. X-ray holography is one of these techniques for imaging of the real space electronic structure with particular strengths in applications requiring drift-free

© 2016 The Author(s). Licensee InTech. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. © 2017 The Author(s). Licensee InTech. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

 imaging (a merit that is derived from Fourier space imaging because drift in Fourier space translates to phase shifts in real space) and in situ sample manipulations.

Using holography for soft X-ray imaging, first demonstrated in a lensless setup in 2004 [1], is a rather novel approach that is still under heavy development and significant improvements have been made in the past few years [2–12]. Still, permanent holography end stations with user support, as common for more established techniques such as (scanning) transmission X-ray microscopy (STXM) or photo emission electron microscopy (PEEM), are not yet available. Therefore, the following chapter discusses the key ingredients and solutions for the main challenges of X-ray holography from an end user perspective. Specifically, the content of this chapter is organized as follows: The basic theory of how to obtain a hologram and how to reconstruct the real space information is presented in Section 2; the tricks of time resolved measurements and how to measure time zero in Section 3; some of the most important considerations for efficient imaging in Section 4; a suggested end station for magnetic imaging in Section 5; steps of how to fabricate suitable samples in Section 6; and finally, an outlook of anticipated future developments in Section 7. For those interested in more fundamental and technical aspects of X-ray holography, I suggest the other specialized literature, for example [9, 13].
