  Lasers with wavelengths of the order of the atomic size are becoming
available. We explore the behavior of light-matter interactions in this
emergent field by considering the atomic Kapitza-Dirac effect. We derive the
diffraction patterns, which are in principle experimentally testable. From a
fundamental point of view, our proposal provides an example of system where the
periodicity of the diffraction grating is comparable to the size of the
diffracted object.
