  We discuss how classical electromagnetic techniques are useful to describe
optical effects in conventional and chiral dielectric systems endowed with
optical activity. Starting from the Maxwell equations and constitutive
relations of the medium, we obtain the wave equation (for the electric field)
that yields the refractive indices and the corresponding propagating modes that
define the electromagnetic wave polarization. This procedure is employed for
bi-isotropic and bi-anisotropic dielectrics, allowing us to determine
birefringence, a manifestation of the space or time inversion breaking, typical
of the chiral media. Such a method can also be applied for axion
electrodynamics and a dielectric supporting an isotropic chiral magnetic
current, similar to the Chiral Magnetic Effect (CME). For a diagonal magnetic
conductivity, two distinct refractive indices are found, associated with left
circularly polarized (LCP) and right circularly polarized (RCP) waves, and
yielding circular birefringence (evaluated in terms of the optical rotatory
power). Additionally, the scenario of a bi-isotropic medium endowed with
isotropic magnetic current is examined, where a rotatory power marked by sign
reversal may work as an optical signature of this particular system.
