IR holographic wire grid polarizers have been introduced by Edmund Optics Inc. The holographic manufacturing technique creates submicron wire grid spacing of 2700 grooves per millimeter. Available in substrates made from barium fluoride, zinc selenide, thallium bromoiodide and germanium, they polarize light from unpolarized infrared laser sources and attenuate light from polarized sources. When two are used together, extinction ratios of >40,000:1 can be achieved. The polarizers feature high transmission out to a wavelength of 30 mm.