  Developing an analytical theory for atomic coherence driven by ultrashort
laster pulses has proved to be challenging due to the breakdown of the rotating
wave approximation (RWA). In this paper, we present an approximate, closed-form
solution to the Schrodinger equation that describes a two-level atom under the
excitation of a far-off-resonance, few-cycle pulse of arbitrary shape without
invoking the RWA. As an example of its applicability, an analytical solution
for Gaussian pulses is explicitly given. Comparisons with numerical solutions
validate the accuracy our solution within the scope of the approximation.
Finally, we outline an alternative approach that can lead to a more accurate
solution by capturing the nonlinear behaviors of the system.
