IMAGING WITH AN ATOMIC-BEAM

FOCUSING of atomic beams has been investigated for more than 40 years(1-9). The formation of images of simple objects such as points or slits has been demonstrated(7-9), but only with long focal lengths and large chromatic aberrations oiling to the velocity distribution of the thermal beam. Lasers can be used to slow and cool the atomic beam(10), reducing the focal length; and by optically narrowing the velocity spread of the beam, chromatic aberrations can be reduced substantially. Here rye report the construction of an atomic imaging device, using a hexapole lens made from permanent magnets, which produces images in the same way as an optical slide projector. A mask is illuminated by a beam of caesium atoms prepared using a laser diode, and its image appears on a 'resonant light screen', where a sheet of laser light excites atomic fluorescence. We can obtain magnified and demagnified images with remarkable resolution, suggesting that this technique might be used to create sub-micrometre atomic structures.