Broadband Polarizers Using Dual-Layer Metallic Nanowire Grids

Broadband polarizers functioning in an extremely wide wavelength range from 0.3 to 5μm 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.