We use a photosensitive layer containing azobenzene moieties to map near field intensity patterns in the vicinity of nano grids fabricated within a thin silver layer. It is known that azobenzene containing polymer films deform permanently during irradiation, following the pattern of the field intensity. The photosensitive material reacts only to stationary waves whose intensity patterns do not change in time. In this study, we have found a periodic deformation above the silver film outside the nanostructure, even if the latter consists of just one groove. This is in contradiction to the widely accepted viewpoint that propagating modes of surface plasmons dominate outside nano grids. We explain our observations based on an electromagnetic hologram formed by the constructive interference between a propagating surface plasmon wave and the incident light. This hologram contains a stationary intensity and polarization grating that even appears in the absence of the polymer layer.