Accurate and robust characterization of volume scattering materials using the intensity-based inverse adding-doubling method

摘要

In several different research disciplines, modelling and simulating light propagation through volume scatteringmaterials is a key necessity. Simulating diffusing and uorescent materials in solid-state lighting and the in-teractions between intense light and skin tissue in biomedicine are just some examples of the widespread needfor accurate volume scattering models. Although modelling volume scattering materials is important for severalresearch fields, there is still no widespread reporting of model properties or of accurate and robust tools toestimate them, especially for lighting research. Most often, researchers estimate the scattering model properties,i.e. the absorption and scattering coefficients and the anisotropy factor, using Mie solutions. These are generallybased on rough estimates of the scattering particle's properties and assume that the particle is perfectly spher-ical or cylindrical. This approach is not well suited for the myriad of volume scattering materials available forillumination research. Our work uses the intensity-based inverse adding-doubling (i-IAD) method to estimatethe volume scattering model properties of samples. In this work, we investigate the feasibility of this methodin an experimental scenario by studying samples made with two different scattering particles embedded in atransparent polymer with different scattering particle concentrations and sample geometries. The light scatteredby the samples is measured and their volume scattering properties estimated with i-IAD. We show the accuracyand robustness of i-IAD by extrapolating the scattering parameters obtained for low concentration samples tohigher concentrations and comparing simulations with experiments for these higher concentrations. Furthermore,measurements of samples that contain both types of scattering particles were also accurately simulated using themodel parameters estimated from low concentration samples. This work demonstrates that the intensity-basedinverse adding-doubling method provides accurate estimates for the volume scattering model parameters andthat they can be generalized for different concentrations, geometries and scattering particle mixtures.