Electromagnetic waves in dissipative media revisited

We present a systematic and self-consistent analysis of the polarization characteristics of monochromatic electromagnetic waves in linear, isotropic, and homogeneous dissipative media. It is shown that in general the transversality property of the waves no longer holds when they propagate in dissipative media. The same is true for electromagnetic waves traveling parallel to the boundary interface if total internal reflection occurs, even in a strictly nondissipative medium. A systematic characterization of elliptically polarized fields for incident s and p waves is presented. Examples in which the time averaged Poynting vector is not parallel to the direction of propagation of the electromagnetic waves are presented. A general expression for the Poynting vector is derived and is interpreted as the power per unit area developed by the electric stress tensor along the direction of propagation of the wave. An equivalent expression is obtained in terms of the magnetic stress tensor with, in general, a different direction of propagation. (C) 2004 American Association of Physics Teachers.