Generation of unipolar pulses from nonunipolar optical pulses in a nonlinear medium

A unipolar electromagnetic pulse is a pulse with nonzero value of the static component of the Fourier spectrum of its real electric field (and not its envelope). We show how to efficiently generate unipolar pulses through propagation of an initially nonunipolar pulse in a nonlinear optical medium. One of the major results is the demonstration that the static component can only be generated in equal portions between the forward- and backward-traveling waves in the presence of nonlinear backscattering in a nonlinear medium.