Full loss compensation in hybrid plasmonic waveguides under electrical pumping

TL;DR

This paper introduces a novel electrically pumped waveguide design that fully compensates for surface plasmon polariton losses at low current densities, enabling lossless nanoscale optical components.

Contribution

It proposes a new metal-insulator-semiconductor waveguide structure that achieves complete SPP loss compensation with significantly lower pump current than previous methods.

Findings

Full loss compensation achieved at 0.8 kA/cm$^2$

Thin insulator layer reduces leakage current

Enables lossless SPP guiding at infrared frequencies

Abstract

Surface plasmon polaritons (SPPs) give an opportunity to break the diffraction limit and design nanoscale optical components, however their practical implementation is hindered by high ohmic losses in a metal. Here, we propose a novel approach for efficient SPP amplification under electrical pumping in a deep-subwavelength metal-insulator-semiconductor waveguiding geometry and numerically demonstrate full compensation for the SPP propagation losses in the infrared at an exceptionally low pump current density of 0.8 kA/cm$^2$. This value is an order of magnitude lower than in the previous studies owing to the thin insulator layer between a metal and a semiconductor, which allows injection of minority carriers and blocks majority carriers reducing the leakage current to nearly zero. The presented results provide insight into lossless SPP guiding and development of future high dense nanophotonic and optoelectronic circuits.