Broadband Light Bending with Plasmonic Nanoantennas

TLDR: Unparalleled wavefront control in a broadband optical wavelength range from 1.0 to 1.9 micrometers is experimentally demonstrated using an extremely thin plasmonic layer consisting of an optical nanoantenna array that provides subwavelength phase manipulation on light propagating across the interface.

Abstract: The precise manipulation of a propagating wave using phase control is a fundamental building block of optical systems. The wavefront of a light beam propagating across an interface can be modified arbitrarily by introducing abrupt phase changes. We experimentally demonstrated unparalleled wavefront control in a broadband optical wavelength range from 1.0 to 1.9 micrometers. This is accomplished by using an extremely thin plasmonic layer (~λ/50) consisting of an optical nanoantenna array that provides subwavelength phase manipulation on light propagating across the interface. Anomalous light-bending phenomena, including negative angles of refraction and reflection, are observed in the operational wavelength range.