Scattering by nanoplasmonic mesoscale assemblies.

Abstract

The flexibility and versatility of nano-assembled plasmonic structures provide platforms for mesoscale tunable optical modulation. Our recently developed model for these nano-assembled plasmonic structures is composed of a dielectric spherical core surrounded by a concentric spherical shell containing a random distribution of gold nanoparticles (AuNPs). This model provides a useful platform for studying the role of a controlled amount of disorder on scattering by a particle. In that context, we explore the angular distribution of scattered light for different sizes (5-20 nm) and filling fractions (0.1-0.3) of the AuNPs in the coatings. The simulations reveal that the coating of AuNPs redistributes power in a way that suppresses angular side lobes, thereby guiding the scattered power preferentially in the forward direction. These results highlight that, with the ability to tune both the spatial and spectral aspects of the scattering profile, these coated structures may serve as a platform for a variety of applications, including passive cloaking and high-resolution imaging.