COHERENT MANIPULATION OF ATOMIC WAVE-PACKETS BY ADIABATIC TRANSFER

We use laser induced adiabatic passage to coherently manipulate the at omic wave packets resulting from subrecoil laser cooling in one, two, and three dimensions by velocity selective coherent population trappin g. Using metastable helium atoms, we demonstrate adiabatic transfer in to a single wave packet or into two coherent wave packets, while retai ning the subrecoil momentum dispersion of the initial wave packets. Th e efficiency of the transfer is nearly perfect in one and two dimensio ns, and of the order of 75% in three dimensions. To a large extent, th e direction of the momentum and the internal state of the atoms descri bed by each of the final wave packets can be chosen at will.