Direct comparison between single-scattering properties of ordered and disordered aggregates of nano-sized scattering centers.

In this study, we examine the single-scattering properties of aggregates of nano-sized spherical scattering centers (spherules) of different sizes and refractive indices, with an emphasis on contrasting the single-scattering properties of ordered and disordered aggregates, holding all other parameters constant. The ordered aggregates are constructed by arranging the spherules in a simple cubic configuration, while the disordered aggregates are constructed using an ideal amorphous solid algorithm. The single-scattering properties of both kinds of aggregates are computed using the superposition -matrix method.

Considerations concerning backscattering in the scattering order formulation of the discrete dipole approximation as applied to non-absorbing scatterers.

The progression of secondary waves emanating from scattering centers within a non-absorbing material in the visible part of the electromagnetic spectrum (wavelength 0.500 µm) is traced using two modeling schemes: the scattering order formulation (SOF) of the discrete dipole approximation (the original SOF) and the SOF with the Twersky approximation, according to which the path of the secondary waves in a successive scattering chain does not loop through the same scattering center more than once (the SOF-Twersky). It is shown that for smaller submicron-sized scatterers (radius 0.

Predicting the refractive index of amorphous materials using the Bruggeman effective medium approximation.

Previous studies have shown that the Lorentz-Lorenz relationship, or molar refractivity/specific refractivity effective medium approximation, enables a reasonable prediction of the refractive index of amorphous water ice, given the refractive index of crystalline water ice. In the current study, we show that the Bruggeman effective medium approximation provides an even closer match to measurements of the refractive index of several amorphous materials, given the refractive index of their crystalline phase. We show that the Bruggeman effective medium approximation provides a good match to measurements of the refractive index of amorphous ice as well.