Photonic hyperinterfaces for light manipulations

Optical metamaterials are building blocks for the control of light behaviors and designs of photonic devices, where the inner interfaces in deep-subwavelength features are expected to have little impact on light transport, based on the concept of homogenization. Here we theoretically and experimentally study a new type of photonic interface (namely a hyperinterface) inside an optical metamaterial made of a zigzag alternating multilayer structure [namely structured metamaterials (SMMs)] in the deep-subwavelength regime. It is found that the subwavelength hyperinterfaces play a great role in the optical properties of such SMMs, and the electromagnetic properties of the hyperinterfaces can be effectively manipulated in a feasible way. In particular, the absorption of the SMMs strongly depends not only on the intrinsic absorption of the SMMs’ unit cells, but also on the structural absorption that is induced by the hyperinterfaces inside the SMMs and their period p , even for the long wavelength limitation. These outcomes are attributed to the dispersion relations of the hyperinterfaces, that is, the interplay of the angle formed by the asymptotes of the iso-frequency contour (hyperbola) of the SMMs’ unit cells and the geometric rotating angle of zigzag structures. Such interplay leads to an effect of clipping and the recombination of energy flow distributions at the hyperinterfaces. Our findings may pave the way to the manipulation of a light field to enhance the conversion efficiency of optoelectronic devices, e.g., solar cells and photodetectors.