We investigate the lateral displacement (Goos-Hänchen lateral shift) of a linearly polarized Gaussian beam
reflected from a corrugated surface between a conventional dielectric and a homogeneous isotropic metamaterial
with a negative index of refraction. We pay particular attention to effects associated with the resonant excitation
of surface plasmon polaritons. The dependence of the lateral displacement on the incident beam parameters is
examined in detail and discussed in different situations among which is the total reflection case. We compare these
characteristics with the limiting case of reflection of a beam from a surface with infinitely periodic corrugations.
The differences between the resonant response of metallic and metamaterial gratings, both supporting surface polaritons,
evidence the different kind of interference processes occurring between the fields radiated by the surface polariton and
the fields reflected by the surface without corrugation. As in any resonance phenomenon, complementary information can
be obtained by studying the associated homogeneous problem, i.e., by finding the characteristics of the electromagnetic
eigenmodes supported by the corrugated interface. In this paper we solve this associated homogeneous problem, showing
how a periodic corrugation affects the characteristics of surface polaritons propagating along the interface between a
conventional dielectric medium and a metamaterial medium with a negative index of refraction.