Single-Shot Randomized Probe Imaging of Structural and Magnetic Samples at a Free Electron Laser

Single-shot imaging is a natural application for Free Electron Lasers (FELs), which produce sub-picosecond flashes of ultraviolet and x-ray light. Due to their intrinsic coherence, FEL beams are well suited for lensless imaging methods such as Coherent Diffractive Imaging (CDI) and holography. However, these methods only work on isolated samples, so masks need to be deposited on most samples to make them compatible. This limits the field of view to a small, fixed region which must be chosen before the start of the experiment. We recently proposed a diffractive imaging approach called Randomized Probe Imaging (RPI) which removes this requirement. Here, we report reconstructions from the first single-shot RPI data collected at an FEL. In single-shot images from a structural test sample, we achieved a full-pitch resolution of 400 nm and a space-bandwidth product of 30,000. We also imaged magnetic domains images of Co/Pt multilayers at the Co M2,3 resonance with reduced resolution, highlighting the possible role of RPI for time-resolved studies of magnetic systems. We will discuss the advantages and limitations of our data, and the prospects for future imaging studies.