REFLECTION OF AN ELECTROMAGNETIC PLANE-WAVE WITH OMICRON-PHASE OR PI-PHASE SHIFT AT THE SURFACE OF AN ABSORBING MEDIUM

An electromagnetic plane wave incident obliquely from a transparent medium onto the surface of an absorbing medium can be reflected with 0 or pi phase shift if (i) the wave is p (TM) polarized, and (ii) the complex relative dielectric function epsilon is such that 0 less than equivalent to vertical epsilon vertical **2/2Re( epsilon ) less than equivalent to 1. Furthermore, the locus of epsilon such that the reflection coefficient for the p polarization is real at the same angle of incidence, is a circle, and that of epsilon **1**/**2 (the complex relative refractive index) is Bernoulli's lemniscate.