Formation of high-frequency two-dimensional interference patterns of surface plasmon polaritons

The formation of high-frequency two-dimensional interference patterns of surface plasmon polaritons in a structure consisting of four diffraction gratings with one-dimensional periodicity in a metallic film has been studied numerically and experimentally. It has been shown that change of linear polarization of the incident radiation to its circular polarization makes it possible to reduce the period of the formed pattern at a fixed wavelength. A similar change in the form of the pattern can be achieved by introducing an equivalent shift to the geometry of the structure.