Propagation of extremely short electromagnetic pulses in a doubly-resonant medium

TL;DR

This paper investigates the propagation of extremely short electromagnetic pulses in a doubly-resonant medium using a Maxwell-Duffing-Lorentz model, revealing stable, hump-structured traveling waves with specific velocity spectra and collision behaviors.

Contribution

It introduces a novel analytical and numerical study of stable, hump-shaped traveling-wave solutions in a Maxwell-Duffing-Lorentz model for electromagnetic pulse propagation.

Findings

Existence of a one-parameter family of traveling-wave solutions.

Continuous velocity spectrum at the lower end, discrete elsewhere.

Traveling waves are stable and collide nearly elastically.

Abstract

Propagation of extremely short electromagnetic pulses in a homogeneous doubly-resonant medium is considered in the framework of the total Maxwell-Duffing-Lorentz model, where the Duffing oscillators (anharmonic oscillators with cubic nonlinearities) represent the dielectric response of the medium, and the Lorentz harmonic oscillators represent the magnetic response. The wave propagation is governed by the one-dimensional Maxwell equations. It is shown that the model possesses a one-parameter family of traveling-wave solutions with the structure of single or multiple humps. Solutions are parametrized by the velocity of propagation. The spectrum of possible velocities is shown to be continuous on a small interval at the lower end of the spectrum; elsewhere the velocities form a discrete set. A correlation between the number of humps and the velocity is established. The traveling-wave solutions are found to be stable with respect to weak perturbations. Numerical simulations demonstrate that the traveling-wave pulses collide in a nearly elastic fashion.