Pulse splitting in light propagation through<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mi>N</mml:mi></mml:math>-type atomic media due to an interplay of Kerr nonlinearity and group-velocity dispersion

Abstract

We investigate the spatiotemporal evolution of a Gaussian probe pulse propagating through a four-level $N$-type atomic medium. At two-photon resonance of probe and control fields, weaker probe pulses may propagate through the medium with low absorption and pulse shape distortion. In contrast, we find that increasing the probe pulse intensity leads to a splitting of the initially Gaussian pulse into a sequence of subpulses in the time domain. The number of subpulses arising throughout the propagation can be controlled via a suitable choice of the probe and control field parameters. Employing a simple theoretical model for the nonlinear pulse propagation, we conclude that the splitting occurs due to an interplay of Kerr nonlinearity and group-velocity dispersion.