Steady-state pulse component in ultrafast pulse propagation in an anomalously dispersive dielectric

We describe a theoretical method to distinguish between the precursors (transient part) and main signal (steady state) for a Gaussian pulse propagating through an anomalously dispersive linear dielectric. According to conventional theory of optical precursors, there is no main signal for Gaussian pulse propagation regardless of the system parameters. In this paper, we show the existence of the main pulse by comparing the conventional asymptotic theory with recently published analytical expressions. Additionally, we show that experimentally observed, asymmetrically extended tails in Gaussian pulse propagation are due to a resonant precursor.