Effect of nonlocality in spatially uniform anisotropic metamaterials.

In this study, we investigate an effect of spatial dispersion in anisotropic metamaterials of regular periodic geometry. We indicate conditions under which a local and nonlocal approach are convergent, as well as the areas of particularly strong nonlocality. Our analysis also reveals that new resonance transitions altering the topology of an iso-frequency surface arise in the presence of spatial dispersion. For the first time, we demonstrate that nonlocality can serve as a new mechanism for tailoring effective dispersion of an anisotropic metamaterial, which opens new venues for novel applications requiring strong direction discrimination of the incident radiation.