X-ray vortices with high topological charge

The aim of this work is to fabricate diffractive optical elements (DOEs) that generate optical vortices with high topological charge and investigate their usefulness for X-rays. Using e-beam lithography and electroplating techniques we fabricated binary amplitude DOEs in gold on silicon nitrade membranes. The first test of the DOEs, showing the ability to generate vortices with topological charge as high as 64 at an energy of 700 eV was performed in a scanning X-ray microscope setup at Twinmic beamline of Elettra Synchrotron. (c) 2006 Elsevier B.V. All rights reserved.