Wideband resonant polarizers made with ultra-sparse dielectric nanowire grids

TL;DR

This paper introduces a novel class of wideband dielectric nanowire grid polarizers that are mostly empty space, offering high reflection and polarization extinction over broad spectral regions, confirmed by experimental results.

Contribution

It presents the design and experimental validation of ultra-sparse dielectric nanowire grid polarizers with wideband spectral properties, a significant advancement over traditional polarizers.

Findings

Achieved ~200 nm wide band of total reflection for one polarization

Demonstrated free transmission for the orthogonal polarization

Experimental results align with theoretical predictions

Abstract

Polarizers are essential in diverse photonics applications including display [1], microscopy [2], polarimetric astrophysical observation [3], laser machining [4], and quantum information processing [5]. Whereas conventional polarizers based on natural crystals and multilayer thin films are commonplace, nanostructured polarizers offer compact integrability [6,7], thermal stability in high-power systems [4,8], and space-variant vector beam generation [9,10]. Here, we introduce a new class of reflectors and polarizers fashioned with dielectric nanowire grids that are mostly empty space. It is fundamentally extremely significant that the wideband spectral expressions presented can be generated in these minimal systems. We provide computed results predicting high reflection and attendant polarization extinction in multiple spectral regions. Experimental results with Si nanowire arrays show ~200-nm-wide band of total reflection for one polarization state and free transmission for the orthogonal state. These results agree quantitatively with theoretical predictions.