Lasing modes in ZnO nanowires coupled to planar metals

TL;DR

This paper presents a model analyzing how metallic substrates like aluminum and silver influence the lasing thresholds of ZnO nanowire lasers, providing insights for optimizing integrated laser devices.

Contribution

A simple, precise model describing mode competition in nanowire lasers on metallic substrates, predicting threshold variations based on substrate material.

Findings

Aluminum substrate reduces lasing threshold

Silver substrate increases lasing threshold

Model guides future design of integrated nanowire lasers

Abstract

Semiconductor nanowire lasers can be subject to modifications of their lasing threshold resulting from a variation of their environment. A promising choice is to use metallic substrates to gain access to low-volume Surface-Plasmon-Polariton (SPP) modes. We introduce a simple, yet quantitatively precise model that can serve to describe mode competition in nanowire lasers on metallic substrates. We show that an aluminum substrate can decrease the lasing threshold for ZnO nanowire lasers while for a silver substrate, the threshold increases compared with a dielectric substrate. Generalizing from these findings, we make predictions describing the interaction between planar metals and semiconductor nanowires, which allow to guide future improvements of highly-integrated laser sources.