Ridged atomic mirrors and atomic nanoscope

Recent results on the reflection of waves from ridged mirrors are discussed. Numerical calculations, analytical estimates and the direct measurements of coefficient of specular reflection of atomic waves from solid-state mirrors are combined. The reflectivity is approximated as an elementary function of period L of ridges, their width l, wavenumber K, grazing angle θ and effective depth w of the van der Waals potential. In a special case L = l, the fit reproduces the reflectivity of flat surfaces. Our approximation allows us to optimize the L at given l and estimate the maximum performance of a ridged mirror. Such a mirror is suggested as a focusing element for the nano-scale imaging system