Diffraction of wave beams in inhomogeneous metamaterials

Diffraction of the bulk and surface wave beams in inhomogeneous metamaterials is considered. It is shown that the structure with alternating layers of dielectric and metamaterial suppress the diffraction spreading. We analyze how the inclusion of such structure inside of the open cavity sufficiently changes its properties. The theory of the surface wave beam diffraction on the structural metamaterial - dielectric interface is developed. Properties of the plane resonator for the surface waves are analyzed.