Engineering multipole plasmons via surface nonlinearity
Phys. Rev. A 114, 023523 – Published 26 August, 2026
DOI: https://doi.org/10.1103/b297-gwwh
Abstract
Multipole plasmon resonances in metallic nanostructures are investigated with an emphasis on their excitation and control via surface nonlinear polarization. Surface-induced second- and third-order nonlinear processes enable the activation of multipole plasmon modes that are absent in the linear optical response. The excitation and enhancement of different multipole plasmons are governed by the combined tuning of geometric ellipticity and excitation configuration, allowing selective mode activation and suppression. Without applying electron beams and structured light, the surface-nonlinearity-based excitation can be a viable scheme for engineering the multipole plasmons under far-field illumination.
