Manipulation of an atomic beam by a computer-generated hologram

TECHNIQUES for manipulating neutral atoms are valuable tools for the investigation of surfaces, acid hold promise for the fabrication of atomic structures for technological applications. The ability to position individual atoms with the accuracy of a crystal lattice constant has been demonstrated(1) using the scanning tunnelling microscope (STM). On the other hand, manipulation with lasers offers a means of controlling atoms in bulk, although it lacks the positional accuracy of the STM. The ability to generate ultra-cold atoms(2-5) using lasers has opened new possibilities: because of their long de Broglie wavelengths, cold atoms are amenable to interferometric manipulation, such as deflection by a grating(6,7) and focusing by a Fresnel lens(8). Here we demonstrate a potentially more flexible approach to atomic manipulation based on holographic principles. We pass a beam of ultra-cold metastable neon atoms through a computer-generated hologram that encodes the Fourier transform of a desired atomic pattern. Diffraction of the atomic beam by the hologram then reconstructs the pattern, in a manner analogous to optical holography. This approach should in principle enable the imposition of arbitrary intensity and phase information onto an atomic beam.