  We express the electromagnetic field propagating in an arbitrary
time-independent non-dispersive medium in terms of an operator that turns out
to be pseudo-Hermitian for Hermitian dielectric and magnetic permeability
tensors Epsilon and Mu. We exploit this property to determine the propagating
field. In particular, we obtain an explicit expression for a planar field in an
isotropic medium with Epsilon and Mu varying along the direction of the
propagation. We also study the scattering of plane waves due to a localized
inhomogeneity.
