Atomic-matter-wave scanner

We report on the experimental realization of an atom optical device that allows scanning of an atomic beam with a controllable diffraction grating for atomic waves. We used a time-modulated evanescent wave field above a glass surface to diffract a continuous beam of metastable neon atoms at grazing incidence. The diffraction angles and efficiencies were controlled by the frequency and form of modulation, respectively. With an optimized shape, obtained from a numerical simulation, we were able to transfer more than 50% of the atoms into the first order beam, which we were able to move over a range of 8 mrad.