Multi-beam generations at pre-designed directions based on anisotropic zero-index metamaterials

We show that anisotropic zero-index metamaterials (AZIMs) can be utilized to realize single- and multiple-beam generations in the pre-designed directions. It has been shown that a high-gain beam will be generated when a line source is located in an AZIM, directing to the AZIM principle-axis direction. By rotating the principle axis to an arbitrary angle, the beam direction is adjusted correspondingly to that angle. Therefore, multi-beams are generated at the desired directions by designing differently oriented AZIMs. An experiment is carried out to validate this property, which shows good agreement to the theoretical analysis. (C) 2011 American Institute of Physics. [doi:10.1063/1.3645628]