  We consider field localizing and concentration of electromagnetic waves
governed by the time-harmonic anisotropic Maxwell system in a bounded domain.
It is shown that there always exist certain boundary inputs which can generate
electromagnetic fields with energy localized/concentrated in a given subdomain
while nearly vanishing in another given subdomain. The theoretical results may
have potential applications in telecommunication, inductive charging and
medical therapy. We also derive a related Runge approximation result for the
time-harmonic anisotropic Maxwell system with partial boundary data.
