  We report a study on light force on a beam of neutral two-level atoms
superimposed upon a few-cycle pulsed Gaussian laser field under both resonant
and off-resonant condition. The phenomena of focusing, defocusing and steering
of the neutral atoms in the laser field is analysed by solving the optical
Bloch equation beyond the rotating wave approximation and the force equation
self-consistently .We find that two-level atoms in an atomic beam could be
focused and defocused for large, positively and negatively detuned interaction
even in the regime of extreme nonlinear optics. The so-called optical potential
may be used for stable trapping of the neutral two-level atoms for large
positively detuned interaction. This work successfully reproduces some of the
features reported in recent experimental and theoretical works.
