Multiple light scattering and near-field effects in a fractal tree-like ensamble of dielectric nanoparticles

TL;DR

This paper investigates how light interacts with complex, fractal-like structures of dielectric nanoparticles, revealing the importance of multiple scattering and near-field effects in accurately modeling their optical properties.

Contribution

It introduces a numerical approach that accounts for multiple scattering and near-field effects in fractal nanoparticle aggregates, improving upon previous single scattering models.

Findings

Multiple scattering significantly affects scattering and absorption cross sections.

Near-field effects are crucial for accurate optical modeling of fractal structures.

Numerical results differ from single scattering analytical predictions, highlighting the importance of comprehensive simulations.

Abstract

We numerically study light scattering and absorption in self-similar aggregates of dielectric nanoparticles, as generated by simulated ballistic deposition upon a surface starting from a single seed particle. The resulting structure exhibits a complex tree-like shape, intended to mimic the morphologic properties of building blocks of real nanostructured thin films produced by means of fine controlled physical deposition processes employed in nanotechnology. The relationship of scattering and absorption cross sections to morphology is investigated within a computational scheme which thoroughly takes into account both multiple scattering and near-field effects. Numerical results are compared with a pre-existing single scattering limited analytical treatment of light scattering in fractal aggregates of small dielectric particles.