Optical precursors in transparent media

TL;DR

This paper provides a theoretical analysis of optical precursors in transparent media, demonstrating that Sommerfeld-Brillouin precursors and related signals can be distinctly observed with amplitudes comparable to the incident pulse, especially in slow-light systems.

Contribution

It offers fully analytical expressions for the step response in dispersive media, revealing observable precursors under realistic experimental conditions, contrasting with previous models.

Findings

Precursors can be distinctly observed with amplitudes comparable to the incident pulse.

Analytical expressions for the entire step response are derived.

Precursors are observable in slow-light systems at realistic parameters.

Abstract

We theoretically study the linear propagation of a stepwise pulse through a dilute dispersive medium when the frequency of the optical carrier coincides with the center of a natural or electromagnetically induced transparency window of the medium (slow-light systems). We obtain fully analytical expressions of the entirety of the step response and show that, for parameters representative of real experiments, Sommerfeld-Brillouin precursors, main field and second precursors "postcursors" can be distinctly observed, all with amplitudes comparable to that of the incident step. This behavior strongly contrasts with that of the systems generally considered up to now.