Model-guided design for optical properties of particulate products

Michael Stingl, Friedrich-Alexander-Universität Erlangen-Nürnberg, Germany

Particulate products exhibit optical properties that depend strongly on particle size, shape, material composition and spatial arrangement. In this talk, we present model-guided approaches for designing these properties, with a particular focus on color.
Depending on particle geometry and the degree of interparticle interaction, different physical models are required: from Mie theory for spherical particles in dilute dispersions, to the discrete dipole approximation for anisotropic particles and T-matrix methods for interacting particle ensembles. These models are combined with suitable ensemble and color models and embedded into mathematical optimization frameworks.
We further address particle dispersity and show how distributions can be incorporated directly into the design problem using the Continuous Stochastic Gradient method. Examples ranging from plasmonic particle dispersions to structural color in photonic crystals illustrate these approaches.