Broadband Polarizers Using Dual-Layer Metallic Nanowire Grids

Broadband polarizers functioning in an extremely wide wavelength range from 0.3 to 5 $\mu$m were developed based on structural design and numerical simulation. By properly selecting the dual-layer nanowire grids including metal materials, grid periods, grid thicknesses, and substrate materials, broadband polarizers could be developed to realize high optical performance. We proposed a broadband polarizer using aluminum nanowire grids on a magnesium fluoride substrate with 80-nm square grids. The proposed polarizer can reach an extinction ratio from 47 to 70 dB and a transmission efficiency from 38% to 94% in the wide wavelength range.