Non-Dispersive Space-Time Wave Packets Propagating in Dispersive Media

TL;DR

This paper demonstrates that space-time wave packets remain stable and non-dispersive in dispersive media, extending their potential for practical applications by generalizing anomalous refraction laws.

Contribution

It proves the stability of space-time wave packets in dispersive media and generalizes the anomalous refraction law to weakly dispersive environments.

Findings

Wave packets are stable in dispersive media.

They are free from temporal spreading caused by dispersion.

The anomalous refraction law is extended to weakly dispersive media.

Abstract

Space-time wave packets can propagate invariantly in free space with arbitrary group velocity thanks to the spatio-temporal correlation. Here it is proved that the space-time wave packets are stable in dispersive media as well and free from the spread in time caused by material dispersion. Furthermore, the law of anomalous refraction for space-time wave packets is generalized to the weakly dispersive situation. These results reveal new potential of space-time wave packets for the applications in real dispersive media.