Wire Grid Polarizer with Silicon Dioxide Side Ribs on Silicon Wire

The wire grid polarizers 10 and 30 described herein, and wire grid polarizers made by methods described herein, can have high performance across a broad range of the ultraviolet spectrum and across a broad angle of incidence. These polarizers can be durable (resistant to heat, moisture, ultraviolet light, and oxidation). The polarizer can include an array of wires 15 on a substrate 11. Each wire 15 can have a silicon core 12 and a pair of silicon dioxide ribs 13. The core 12 can be sandwiched between the pair of ribs 13, with each rib 13 adjacent to a sidewall 12s of the core 12. A rib width W13 can be ≥4 nm. Each wire 15 can also include a silicon dioxide cap 14. The core 12 can be encircled by a silicon dioxide ring 17.