  We report a study on the optical dipole force in a ladder like three level
atomic systems in the context of coherent population transfer with the chirped
few-cycle-pulse laser fields. The phenomenon of coherent population transfer is
investigated by numerically solving the appropriate density matrix equations
beyond the rotating wave approximation. On the other hand, optical dipole force
is calculated by numerically solving the force equation and density matrix
equations self-consistently. By analysing the centre-of-mass motion, it is
shown that the optical dipole force with chirped pulses may be used for
focusing and defocusing of atoms in an atomic beam similar to the near or
non-resonant optical dipole force. Moreover, the robustness of the population
transfer against the variation of the pulse parameters and the effect of the
variation of the Rabi frequencies and the chirp rates on the optical dipole
force are also investigated. The proposed scheme may open new perspectives in
the focusing and de-focusing of atoms and molecules in an atomic beam, since
this scheme mitigates the demand for the generation of transform-limited pulse
laser fields at arbitrary frequencies.
