Polariton excitation in epsilon-near-zero slabs: transient trapping of slow light

TL;DR

This paper demonstrates how epsilon-near-zero slabs can transiently trap electromagnetic pulses, excite polariton modes, and significantly slow light, offering new control mechanisms for electromagnetic wave manipulation.

Contribution

It introduces a numerical and analytical study of transient polariton excitation and slow light trapping in epsilon-near-zero slabs, revealing new insights into dynamic electromagnetic control.

Findings

Transient trapping of electromagnetic pulses in epsilon-near-zero slabs.

Excitation of virtual polariton modes with slow damping.

Significant reduction in group velocity enabling slow light control.

Abstract

We numerically investigate the propagation of a spatially localized and quasi-monochromatic electromagnetic pulse through a slab with Lorentz dielectric response in the epsilon-near-zero regime, where the real part of the permittivity vanishes at the pulse carrier frequency. We show that the pulse is able to excite a set of virtual polariton modes supported by the slab, the excitation undergoing a generally slow damping due to absorption and radiation leakage. Our numerical and analytical approaches indicate that in its transient dynamics the electromagnetic field displays the very same enhancement of the field component perpendicular to the slab, as in the monochromatic regime. The transient trapping is inherently accompanied by a significantly reduced group velocity ensuing from the small dielectric permittivity, thus providing a novel platform for achieving control and manipulation of slow light.