  The theoretical description for the reflectivity properties of dielectric,
metal and semiconductor plates coated with graphene is developed in the
framework of the Dirac model. Graphene is described by the polarization tensor
allowing the analytic continuation to the real frequency axis. The plate
materials are described by the frequency-dependent dielectric permittivities.
The general formulas for the reflection coefficients and reflectivities of the
graphene-coated plates, as well as their asymptotic expressions at high and low
frequencies, are derived. The developed theory is applied to the
graphene-coated dielectric (fused silica), metal (Au and Ni), and semiconductor
(Si with various charge carrier concentrations) plates. In all these cases the
impact of graphene coating on the plate reflectivity properties is calculated
over the wide frequency ranges. The obtained results can be used in many
applications exploiting the graphene coatings, such as the optical detectors,
transparent conductors, anti-reflection surfaces etc.
