Optical silicon for silicon windows is grown using the Czochralski method to economically produce silicon that is guaranteed to be 99.99% pure. Silicon windows are available as optical grade in mono-crystalline and polycrystalline for use in infrared systems operatingin the 3 – 5 micron range. The silicon’s low density gives it an advantage over other infrared materials with optical transmission greater than 52%.

Silicon windows made in floatzone optical silicon due to its low oxygen content the transmission is significantly higher at 9 microns than Czochralski gown (Cz) silicon. Floatzone silicon windows are often used when high purity silicon is required.

Optically polished silicon windows can be polished by diamond or chemically polished in an extensive size range to degrees of specification with additional machining eg. Drilling of holes and recesses.

Silicon windows are used as spectroscopic cell windows, silicon substrates for multi-layer infrared filter coatings, IR spectroscopy and windows in infrared systems for infrared transmission.