Determination of refractive index of various materials on Brewster angle

TL;DR

This paper investigates the causes of residual reflected light near Brewster's angle, emphasizing factors like polarization purity and surface roughness, and demonstrates Brewster refractometry's advantages for various materials.

Contribution

It provides a detailed analysis of residual reflections near Brewster's angle and highlights the robustness of Brewster refractometry across different material surfaces.

Findings

Residual reflected light occurs due to incomplete polarization and setup angles.

Reflected light polarization changes smoothly near Brewster's angle.

Brewster refractometry is effective regardless of surface topology or scattering.

Abstract

Studied experimentally the origin of the non-zero reflection of p-polarized radiation (TM) of Brewster's angle. The results have shown the residual reflected light in the vicinity of Brewster angle occurs due to inaccessibility 100% polarization degree the incident linearly-polarized radiation and installation of the zero azimuthal angle. These factors create the s-component of the radiation reflected from the examined surface indeed. A smooth change of reflected light polarization in the vicinity of Brewster angle in the sequence p-s-p appears due to the changing power proportion of reflected p-, and s-components but not is the result of the atomically thin transitional layer at the border of the material/environment according to Drude model. Metrological aspects of refractive index measurement by Brewster angle are investigated: due to the above-mentioned factors, as well as due to the contribution of the reflected scattered light caused by on residual roughness of the optical surface. Advantages of Brewster refractometry for any materials and films without restrictions on the topology of samples and their light scattering and absorption are demonstrated