Resonance amplification of left-handed transmission at optical frequencies by stimulated emission of radiation in active metamaterials

TL;DR

This paper demonstrates that active metamaterials with an active medium layer can extend left-handed resonance transmission into the visible spectrum by compensating ohmic losses through stimulated emission, enabling resonance restoration up to 610 nm.

Contribution

It introduces a novel active metamaterial design that restores left-handed transmission at optical frequencies using stimulated emission to overcome metallic losses.

Findings

Left-handed transmission can be extended to 610 nm.

Threshold gain levels depend on the scaling of the metamaterial units.

Resonance amplification relies on the lasing spaser mechanism.

Abstract

We demonstrate that left-handed resonance transmission from metallic metamaterial, composed of periodically arranged double rings, can be extended to visible spectrum by introducing an active medium layer as the substrate. The severe ohmic loss inside metals at optical frequencies is compensated by stimulated emission of radiation in this active system. Due to the resonance amplification mechanism of recently proposed lasing spaser, the left-handed transmission band can be restored up to 610 nm wavelength, in dependence on the gain coefficient of the active layer. Additionally, threshold gains for different scaling levels of the double-ring unit are investigated to evaluate the gain requirement of left-handed transmission restoration at different frequency ranges.