Focusing Kinoform Lenses: Optical Design and Experimental Validation Available to Purchase

X‐ray focusing lenses with a kinoform profile are high brilliance optics that can produce nano‐sized beams on 3rd generation synchrotron beamlines. The lenses are fabricated with sidewalls of micrometer lateral size. They are virtually non‐absorbing and therefore can deliver a high flux over a good aperture. We are developing silicon and germanium lenses that will focus hard x‐ray beams to less than 0.5 μm size using a single refractive element. In this contribution, we present preliminary optical design and experimental test carried out on ID06 ESRF: the lenses were used to image directly the undulator source, providing a beam with fwhm of about 0.7 μm.