Materials Dispersion Effects on Dielectric Nanophotonics Devices

The effect of the material dispersion can be quantified either by the Abbe number or Group Velocity Dispersion (GVD). However, we show that these traditional techniques are not well suitable to quantify the materials dispersion effects on optical quantities in dielectric nanophotonic devices. Here, we apply classical electrodynamic theory to show that the complete description of materials dispersion properties leads to an additional term related to the materials' group indexes. Based on that, we define a ratio factor capable of exactly quantifying the materials dispersion effects on any optical quantity at a specific wavelength. We also find that a conservative estimative can be done by the ratio between the highest-index material' group index and its refractive index (n _g ^M / n _M ) We believe that the results presented here may be useful during the modeling and simulation of nanophotonic devices.