High performance plasmonic waveguide based on perovskite-alkali metal structure

Abstract Perovskite materials have recently emerged as promising gain materials due to their exceptional optical properties. Concurrently, alkali metals offer new prospects for plasmonics because of their low intrinsic losses. However, the integration of these two material classes into hybrid plasmonic devices remains largely unexplored. In this work, we propose a hybrid plasmonic waveguide consisting of a dielectric-coated sodium nanowire and a perovskite nanowire, separated by a nanoscale gap. The modal characteristics of this structure are quantitatively analyzed at a wavelength of 800 nm using the finite element method. The supported mode exhibits strong plasmonic field confinement, a high figure of merit, and low propagation loss. These favorable modal properties lead to a remarkably low gain threshold of 0.0373 μm −1 and a Purcell factor exceeding 137. These findings not only offer a new design strategy for low-loss plasmonic devices but also demonstrate the significant potential of perovskite-alkali metal structures for applications in integrated nanophotonics, including subwavelength waveguides, low-threshold nanolasers, and optical resonators.