Silver nanowire array infrared polarizers

A silver nanowire array micropolarizer within an anodic alumina membrane (AAM) was fabricated by anodization of pure Al foil and electrodeposition of Ag, respectively. X-ray diffraction, scanning electron microscopy, and transmission electron microscopy investigations reveal that the nanowires are essentially single crystals, and have an average diameter of 90 nm. Spectrophotometer measurements show that the silver nanowire arrays embedded in the AAM can only transmit vertically polarized light to the wires. An extinction ratio of 25–26 dB and average insertion loss of 0.77 dB in the wavelength range 1–2.2 μm were obtained, respectively. Therefore the Ag nanowire/AAM can be used as a wire-grid type polarizer.