  Based on molecular optics we investigate the reflection and refraction of an
electromagnetic wave between two semi-infinite anisotropic magnetoelectric
materials. In terms of Hertz vectors and the principle of superposition, we
generalize the extinction theorem and derive the propagation characteristics of
wave. Using these results we can easily explain the physical origin of Brewster
effect. Our results extend the extinction theorem to the propagation of wave
between two arbitrary anisotropic materials and the methods used can be applied
to other problems of wave propagation in materials, such as scattering of
light.
