Experimental demonstration of deflection angle tuning in diffraction-inspired unidirectional structures

Direction selective transmission regimes obtainable in the framework of the Lorentz reciprocity have lately attracted scientist community attention. Unlike nonreciprocal structures, reciprocal ones are eminently passive and generally much simpler. Enabling direction selective regimes with reciprocal structures requires breaking the spatial inversion symmetry. With this aim in view, different strategies have been proposed, such as higher diffraction orders excitation, polarization conversion, and bending transmission channels in prism-like configurations. Here, the first approach is implemented for a fishnet metamaterial loaded with a dielectric grating. It is shown that a very compact volumetric device can be designed while maintaining direction selectivity features.