Functional optical metamaterials usually consist of absorbing, anisotropic, and often noncentrosymmetric structures of a size that is only a few times smaller than the wavelength of visible light. If the structures were substantially smaller, excitation of higher-order electromagnetic multipoles in them, including magnetic dipoles, would be inefficient. The required non-negligible size of metamolecules, however, makes the material spatially dispersive, so that its optical characteristics depend on the light propagation direction. We consider the possibility to use this usually unwanted effect. We present a theoretical model that allows one to study the interaction of such spatially dispersive metamaterials with optical beams. Applying the model, we show that a strong spatial dispersion, combined with optical anisotropy and absorption, can be used to efficiently control propagational characteristics of optical beams and create new types of optical elements.
- beam propagation
- spatial dispersion