Nonstationary electromagnetics of controllably dispersive media

TL;DR

This paper explores the dynamics of waves in media with controllably changing dispersion properties, revealing new effects when group and phase velocities vary with position and time.

Contribution

It introduces a framework for analyzing wave propagation in nonstationary, dispersive media with controllable dispersion, highlighting novel dynamic phenomena.

Findings

Wave dynamics differ significantly in dispersive vs. nondispersive media with time-dependent velocities.

New kinetic effects emerge due to the controllable dispersion properties.

Theoretical comparison of wave behavior in different media types.

Abstract

Recent experiments have demonstrated that it is possible to alter the dispersion of a medium without significantly altering its absorption or refractive index and that this may be done while a wave propagates through the medium. This possibility opens up a new set of potential experiments to the field of nonstationary optics. We consider the basic kinetics of waves propagating through a medium whose group and phase velocities are a function of position and time. We compare the dynamics of waves propagating through two homogeneous media, one a nondispersive medium with a time dependent phase velocity, and one a dispersive medium with a time dependent group velocity and show that new dynamic effects accompany new kinetic ones.