Layered synthetic X-ray mirrors: Fabrication, tests and applications

No existing material permits the principles on which classical mirrors and refractive lenses are based to be extended from the visible to the X-ray region. So the X-ray and UV ranges suffer from a lack of optical devices. Since a few years ago, progress in microfabrication and evaporation technologies has permitted X-ray-UV interferential optics to be prepared, which are equivalent to dielectric multilayer mirrors and Fresnel zone lenses used in the visible range. These devices are based on the diffraction phenomenon, so they are less demanding of values of optical indices than classical mirrors and lenses. This paper briefly summarizes how to design, to produce and to test the performance of such new artificial Bragg reflectors optimized for the X-ray and X-Ray-UV wavelength range. Examples of applications are given to illustrate the new possibilities of X-ray optics offered by such interferential X-ray mirrors. Techniques used to prepare and test stacks of ultrathin films are briefly reviewed.