Nonlocality in anisotropic optical metamaterials

We analyse and compare the effects of the spatial dispersion and structural anisotropy on the spectrum of a metamaterial slab. Dielectric function of the slab we describe within Drude-Lorentz approximation. Anisotropy is of the slab is introduced through the anisotropy of plasma frequencies corresponding to the different component of the permittivity tensor. Spatial dispersion is considered within hydrodynamical approximation which is suitable for a wide range of spatial dispersive systems.