On Brewster’s angle of metals

We derive an elementary relation for the determination of the pseudo-Brewster angle of metals as a function of frequency. The pseudo-Brewster angle is defined as the angle where the reflection is minimal, i.e., the absorption is maximal. A comparison of the approximated values with the exact ones shows that the former are very accurate for photon energies below the Drude plasma frequency. Additionally we give two very simple expressions for a fast and surprisingly good estimate at low and high photon energies.