The interest in Bragg-Fresnel optics is based on their unique properties as dispersive and focusing elements. First successful demonstrations of the Bragg-Fresnel principle were reported in 1984-1986 using multilayer and crystalline substrates. The general principles of Bragg-Fresnel diffraction were first formulated in the work of Aristov in 1986. The use of Fresnel focusing in combination with total external reflection was also shown. Since that time Bragg-Fresnel lenses have been used at several synchrotron radiation facilities to construct microprobes imaging beam monitors and time-resolved micro-plasma systems.
The theory of Bragg-Fresnel optics has already been published. Unfortunately, the main advantage of the Bragg-Fresnel optics, the combination of a monochromator and focusing element in one device, is at the same time the main limitation of Bragg-Fresnel application.
The necessity to design an optical element for a particular geometry and one fixed energy conflicts with the desired flexibility of the experimental arrangement and limits the number of possible experimental methods, mainly to μ-fluorescence analysis and μ-diffraction. The properties of static, made by etching including a metallic structure on the surface of multilayers and crystals, or dynamic, produced by surface and volume acoustic waves were measured and calculated. Bragg-Fresnel gratings are basic elements for the construction of a variety of X-ray optical devices including fast X-ray modulators and spectrometers. Understanding their properties is essential for the design of efficient high resolution, focusing dispersive X-ray optics.