  To study the optical rotation of the polarization of light incident on
multilayer systems consisting of atomically thin conductors and dielectric
multilayers we present a general method based on transfer matrices. The
transfer matrix of the atomically thin conducting layer is obtained using the
Maxwell equations. We derive expressions for the Kerr (Faraday) rotation angle
and for the ellipticity of the reflected (transmitted) light as a function of
the incident angle and polarization of the light. The method is demonstrated by
calculating the Kerr (Faraday) angle for bilayer graphene in the quantum
anomalous Hall state placed on the top of dielectric multilayers. The optical
conductivity of the bilayer graphene is calculated in the framework of a
four-band model.
