Atom lens without chromatic aberrations
  We propose a lens for atoms with reduced chromatic aberrations and calculate its focal length and spot size. In our scheme a two-level atom interacts with a near-resonant standing light wave formed by two running waves of slightly different wave vectors, and a far-detuned running wave propagating perpendicular to the standing wave. We show that within the Raman-Nath approximation and for an adiabatically slow atom-light interaction, the phase acquired by the atom is independent of the incident atomic velocity. 
Maxim A. Efremov, Polina V. Mironova, and Wolfgang P. Schleich
physics.atom-ph physics.optics quant-ph