Loss-Free Negative-Index Metamaterials Using Forward Light Scattering in Dielectric Meta-Atoms

Abstract

Negative-index metamaterials are significantly limited by their inherent losses. We demonstrate that a negative index without dissipative and reflective losses can be achieved in subwavelength dielectric cuboid arrays. We can avoid reflection by making dielectric cuboids exhibit the resonant forward scattering of light, while dissipative loss is inherently absent in dielectric materials. A joint study combining theoretical and experimental research demonstrates that loss-free negative-index metamaterials can be realized. They fulfill the criteria of negative refraction based on causality, while conventional active loss compensation schemes lead to the disappearance of negative refraction by causality.