US Patent 10139536 Embedded wire grid polarizer with high reflectivity on both sides

A wire grid polarizer (WGP) 10 can include wires 15 sandwiched between a first pair of thin-film layers 21 (with a first transparent layer 11 and a second transparent layer 12) and a second pair of thin-film layers 22 (with a third transparent layer 13 and a fourth transparent layer 14). An index of refraction of each outer transparent layer 11 and 14 can be greater than an index of refraction of the adjacent inner transparent layer 12 and 13, respectively. Material composition of the outer transparent layers 11 and 14 can be the same and 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. The wires 15 can be embedded for protection.