US Patent 10139538 Wire grid polarizer with high reflectivity on both sides

A wire grid polarizer (WGP) 10 can include a reflective layer 15 sandwiched on each side by a pair of transparent layers (11-12 and 13-14). An index of refraction of each outer transparent layer 11 or 14 can be greater than an index of refraction of the adjacent inner transparent layer 12 or 13, respectively. Material composition of the outer transparent layers 11 and 14 can be the same, material composition of the adjacent inner transparent layers 12 and 13 can be the same. There can be high reflection of one polarization (e.g. Rs1>93% and Rs2>93%) for light incident on either side of the WGP.