Degree of polarization of reflected light on a fractal-fractal interface

Abstract

Fractal media model has been used to describe materials with irregularities such as porous media, disordered media, and colloidal aggregates. Fractal slabs have also been used to model surface roughness. To further understand the properties of these materials, we study the behavior of the polarization of reflected light on the interface of two fractal media in relation to the fractional dimension and the permittivity ratio of the media. The Degree of Polarization of the Reflected Light (DoP) is derived from the fractional Fresnel coefficients and is used to evaluate the polarization in the fractal interface. Our calculations show that the peak of the DoP shifts (with respect to the DoP peak for the equivalent integer-integer interface) toward the glancing angle as the permittivity ratio between the two fractal media increases. In a fractal-dielectric interface, the DoP shifts to the normal angle as the fractional dimension is decreased and shifts to the glancing angle in a dielectric-fractal interface. We also observed a negative DoP in the case of dimensions lower than 1.4 in the fractal-dielectric interface. Our research shows that the fractional dimension has a considerable effect on the DoP of an interface and its sensitivity and varying the dimension shifts the DoP curves. The results show that varying the fractional dimension can be used to model irregularity and the DoP can be used to characterize these materials.