Laser-Driven Hybridization of a Surface Plasmon Resonance Collective Mode in a Monolayer of Silver Nanoparticles

Abstract

Laser-driven hybridization of a collective surface plasmon mode of a monolayer of silver nanoparticles has been studied as a function of irradiation power density. Two collective surface plasmon modes were identified in the spectra, namely, T- and P-modes, associated with the induced particle dipoles parallel and perpendicular to the plane of the layer. The P-mode was in resonance with the laser irradiation wavelength (488 nm). The magnitude, spectral position, and bandwidth of the two modes depend significantly differently on the laser power density. The laser-driven changes of the T-mode were attributed to the thermal effects caused by laser heating of the sample. Meanwhile, the spectral behavior of the P-mode is governed by resonant excitation by an Ar laser.