Optical Negative Refraction in Bulk Metamaterials of Nanowires

TLDR

Negative refraction in metamaterials has generated excitement, yet creating a bulk metamaterial that exhibits visible‑frequency negative refraction has been hindered by resonance losses and fabrication challenges. The authors fabricated bulk nanowire metamaterials that exhibit negative refraction across all incident angles in the visible spectrum. These nanowire metamaterials demonstrate low‑loss, broadband visible‑frequency negative refraction far from resonance, promising advances in imaging, 3D light manipulation, and optical communication.

Abstract

Negative refraction in metamaterials has generated great excitement in the scientific community. Although negative refraction has been realized in microwave and infrared by using metamaterials and by using two-dimensional waveguide structures, creation of a bulk metamaterial showing negative refraction at visible frequency has not been successful, mainly because of the significant resonance losses and fabrication difficulties. We report bulk metamaterials made of nanowires that show such negative refraction for all incident angles in the visible region. Moreover, the negative refraction occurs far from any resonance, resulting in a low-loss and a broad-band propagation at visible frequencies. These remarkable properties can substantially affect applications such as imaging, three-dimensional light manipulation, and optical communication.