Surface lattice plasmons are formed by the coupling of localized surface plasmon (LSP) resonances of individual plasmonic nanoparticles and the Rayleigh anomalies due to a periodic arrangement. Because of the narrow resonance linewidth and high quality factor, they are attractive in many applications including fluorescence enhancement, plasmonic nanolasers, nonlinear optics and ultrasensitive sensing. In this work, the authors comprehensively analyze the crucial roles played not only by the periodicity, but also by the dielectric environment and by the incident polarization on the formation and properties of lattice modes. With both numerical simulations and experimental measurements of the dispersion curves, they gain insights into the nature of lattice plasmons and manage to provide design rules. Following these rules, they achieve strikingly high quality factors of several hundred for lattice modes in the visible spectrum using gold nanoparticle arrays. For lattice modes in the near-UV and visible spectral ranges using aluminum nanoparticle arrays, they obtain quality factors of the same magnitude as those obtained for isolated gold nanoparticles, although aluminum has higher intrinsic losses and worse surface roughness than gold.
You must log in
to add comments.