  The optical Yoneda and Brewster scattering phenomena are studied
theoretically based on pertubative solutions of the reduced Rayleigh equations.
The Yoneda phenomenon is characterized as an enhancement of the intensity of
the diffuse light scattered by a randomly rough interface between two
dielectric media when the light is observed in the optically denser medium. The
intensity enhancement occurs above a critical angle of scattering which is
independent of the angle of incidence of the excitation. The Brewster
scattering phenomenon is characterized by a zero scattered intensity either in
the reflected or transmitted light for an angle of scattering which depends on
the angle of incidence. We also describe a generalization of the Brewster
scattering phenomenon for outgoing evanescent waves and circularly-polarized
waves. The physical mechanisms responsible for these phenomena are described in
terms of simple notions such as scalar waves, oscillating and rotating dipoles
and geometrical arguments, and are valid in a regime of weakly rough
interfaces.
