DIFFRACTION AND REFLECTION OF A SLOW METASTABLE NEON BEAM BY AN EVANESCENT LIGHT GRATING

The first experimental observation is reported of an atomic beam diffracted by coherent transfer of two photon momenta from an evanescent standing laser field. The incident atomic beam of laser slowed metastable neon atoms had a mean velocity of 25 m/s as it was transversely compressed to a diameter below 0.15 mm and to sub Doppler temperatures. Direct images of diffraction patterns taken by a high resolution two-dimensional detector showed specular reflection of the beam of metastable neon atoms up to 74 mrad and clearly the second diffraction order from 81 to 92 mrad.