Highly efficient and broadband optical polarizers based on dielectric nanowires.

The development of optical materials and devices that mimic the functionalities of conventional bulky optical components but on a much smaller footprint remains an important priority in nanophotonics. One prominent class of such optical elements are polarizers that change the polarization state of incident light. Recently, advances in plasmonic and photonic metasurfaces have given rise to different classes of subwavelength polarizers. Low efficiency and narrow band of operation remain, however, significant challenges. Here, we propose a device based on high refractive index dielectric nanowire dimers and analyze its working mechanism as efficient and broadband circular polarizers in the optical region of the electromagnetic spectrum. Our analysis predicts that a polarization conversion of roughly 97% with a transmission efficiency of more than 93% in a broad range of the visible spectrum is possible with nanowire dimers.