25-02E

We consider a simple model of one-dimensional magnetoelectric crystal and examine the propagation of an electromagnetic wave through such a medium. Calculating the dispersion relation k(ω) allows us to illustrate how the spread of the electromagnetic wave can be controlled by a magnetic/electric field. We demonstrate explicitly the directional nonreciprocity, i.e., the difference in the electromagnetic wave propagation between opposite directions. Our rigorous calculations should be useful for more realistic (and less tractable mathematically) models of magnetoelectric media.