Real-time tunable lasing from plasmonic nanocavity arrays

TLDR

Plasmon lasers enable ultrasmall mode confinement and ultrafast dynamics, yet most rely on solid gain materials that preclude dynamic tuning. The study presents a method for real‑time, tunable lattice plasmon lasing using gold nanoparticle arrays with liquid gain media. The authors employ optically pumped gold nanoparticle arrays in microfluidic channels, where liquid dye or gain media with varying refractive indices tune the lasing wavelength via dielectric changes. Time‑resolved measurements reveal distinct lifetimes below and above threshold, and the tunable lattice plasmon lasers enable real‑time detection of weak nanoscale processes.

Abstract

Abstract Plasmon lasers can support ultrasmall mode confinement and ultrafast dynamics with device feature sizes below the diffraction limit. However, most plasmon-based nanolasers rely on solid gain materials (inorganic semiconducting nanowire or organic dye in a solid matrix) that preclude the possibility of dynamic tuning. Here we report an approach to achieve real-time, tunable lattice plasmon lasing based on arrays of gold nanoparticles and liquid gain materials. Optically pumped arrays of gold nanoparticles surrounded by liquid dye molecules exhibit lasing emission that can be tuned as a function of the dielectric environment. Wavelength-dependent time-resolved experiments show distinct lifetime characteristics below and above the lasing threshold. By integrating gold nanoparticle arrays within microfluidic channels and flowing in liquid gain materials with different refractive indices, we achieve dynamic tuning of the plasmon lasing wavelength. Tunable lattice plasmon lasers offer prospects to enhance and detect weak physical and chemical processes on the nanoscale in real time.