Highlight
- The refractive index of nanocomposite was predicted by a physics-based FEA model.
- It proves nanoparticle’s morphology can affect the effective refractive index.
- Those capabilities complement the limitation of the effective medium theories.
- The method shown can serve as a design guideline of optical nanocomposites.
Abstract
This study introduces a method to predict the refractive index (RI) of nanocomposites with the Finite Elements Analysis (FEA) based on the Fabry-Pérot interference. The efficacy was verified by comparing the estimated composites’ RI with the available data in the literature. In the experimental verification, the FEA-based prediction showed closer results with the measurement as compared to the effective medium approximation (EMA) approaches, which are prevalently used to predict the physical properties of nanocomposites. Due to the modeling capability, the FEA-method could investigate the effect of the nanoparticle morphology (particle size, shape, and orientation) and distribution. Large particle size, particle agglomeration in high electric-field amplitude region, and particle elongation along the light oscillating direction are found to be the major factors to enhance the RI of composites. The underlying mechanism of RI changing is attributed to the light scattering by embedded nanoparticles, which provides one potential real-time RI tuning schematic.
https://www.sciencedirect.com/science/article/pii/S1359836821005126