Dissipation-Induced Super Scattering and Lasing PT-Spaser

TL;DR

This paper demonstrates that a PT-symmetric plasmonic metafilm can exhibit giant transmission, reflection, and lasing behavior at specific dissipation levels, acting as a coherent radiation source with tunable super scattering.

Contribution

It introduces a dissipation-controlled PT-spaser that achieves super scattering and lasing in a plasmonic metafilm, revealing new ways to control light-matter interactions.

Findings

Giant transmission and reflection occur at the same wavelength near spectral singularity.

Tuning substrate dissipation induces super scattering and lasing.

Metafilm acts as a coherent light source with dissipation as a control parameter.

Abstract

Giant transmission and reflection of a finite bandwidth are shown to occur at the same wavelength when the electromagnetic wave is incident on a periodic array of PT-symmetric dimers embedded in a metallic film. Remarkably, we found that this phenomenon vanishes if the metallic substrate is lossless while keeping other parameters unchanged. When the metafilm is adjusted to the vicinity of a spectral singularity, tuning substrate dissipation to a critical value can lead to supper scattering in stark contrast to what would be expected in conventional systems. The PT-synthetic plasmonic metafilm acts as a lasing PT-spaser, a planar source of coherent radiation. The metallic dissipation provides a mean to couple light out of the dark modes of the PT- spaser. Above a critical gain-loss coupling, the metafilm behaves as a meta-gain medium with the meta-gain atoms made from the PT-plasmonic dimers. This phenomenon implies that super radiation is possible from a cavity having gain elements by tuning the cavity dissipation to a critical value.