We study the non-reciprocal modification of flat-top optical pulses via a one-dimensional photonic
band-gap structure with Weyl semimetal-based defect layers due to their wide range of applications,
such as high-speed communication, nonlinear optical switching, and ultrafast pump–probe
experiments. We apply the transfer matrix method to obtain the transmission spectrum of the
structure. Also, the Fourier transform technique is used to investigate the effect of the propagation
direction of the incoming pulse on the time profile of the outgoing pulse. Then we examine the effect
of the carrier frequency and duration of the incoming pulse on the length, energy, and magnetic field
distribution of the outgoing pulse. It is shown that the time profile of an incoming flat-top pulse may
modify to a nearly flat-top, single-peak, or oscillatory multi-peak time profile depending on the carrier
frequency, length, and propagation direction of the incoming pulse.