Non-local metasurfaces for perfect control of reflection and transmission

Reflected and transmitted waves can be shaped by controlling the phase of reflection and transmission coefficients of antenna arrays or thin composite layers. This is the operational principle of phased array antennas and reflectarrays, which can be used also to design reflecting and transmitting metasurfaces. Recently, it has been recognized that such phase-gradient reflectors always produce some parasitic scattering into unwanted directions. In this review talk we present and discuss our recent results on non-local (spatially dispersive) gradient meta-surfaces which do not have this drawback and demonstrate perfect anomalous reflection and transmission of plane waves into any desired direction.