A planar waveguide with impedance boundary, composed of non-perfect metallic
plates, and with passive or active dielectric filling is considered. We show
the possibility of selective mode guiding and amplification when homogeneous
pump is added to the dielectric, and analyze differences in TE and TM mode
propagation. Such a non-conservative system is also shown to feature
exceptional points, for specific and experimentally tunable parameters, which
are described for a particular case of transparent dielectric.Comment: Optics Letters (2016
