Mimicking visual properties of metamaterials with METATOYs

A METATOY is an array of small, telescopic optical components forming a sheet that re-directs transmitted light rays. The name is an acronym for "metamaterial for rays", reflecting analogies with metamaterials in the usual sense. From a distance, the view through a single telescopic optical component is one pixel of the view through the METATOY as a whole. In the case of an array of identical optical components, the METATOY behaves like a homogeneous, but pixellated, window that can have very unusual optical properties. Here we give an overview of METATOY research, focusing on the similarities between METATOYs and standard metamaterials. These include mimicking a few of the visual properties of metamaterials on everyday scales and across the entire visible spectrum.