Fresnel polarisation of infra-red radiation by elemental bismuth

TL;DR

This paper analyzes the Fresnel reflection and transmission of infrared radiation at an interface involving elemental bismuth, focusing on polarization effects and the concept of a pseudo Brewster's angle.

Contribution

It derives Fresnel coefficients for a lossy conductor and connects them to lossless media, applying this to understand polarization by bismuth in the infrared range.

Findings

Derived Fresnel coefficients for lossy conductors.

Identified a pseudo Brewster's angle for bismuth.

Explained polarization effects in infrared radiation.

Abstract

We revisit the classical problem of electromagnetic wave refraction from a lossless dielectric to a lossy conductor, where both media are considered to be non-magnetic, linear, isotropic and homogeneous. We derive the Fresnel coefficients of the system and the Poynting vectors at the interface, in order to compute the reflectance and transmittance of the system. We use a particular parametrisation of the referred Fresnel coefficients so as to make a connection with the ones obtained for refraction by an interface between two lossless media. This analysis allows the discussion of an actual application, namely the Fresnel polarisation of infra-red radiation by elemental bismuth, based on the concept of pseudo Brewster's angle.