Due to its minimal surface curvature and high refractive index, Ge is an ideal choice for low-power imaging systems. The color difference is small and usually does not require correction. Germanium is most widely used in 2 μ M-12 μ Lenses and windows in infrared systems within the range of m. Germanium is a high refractive index material, which is used to manufacture attenuated total reflection (ATR) prisms for Spectroscopy. Its refractive index is sufficient to make germanium an effective natural 50% beam splitter without the need for coating. It is also widely used as a substrate for the production of filters. Germanium covers the entire 8-14 μ M thermal band and used for thermal imaging lens systems. It can be coated with diamond AR coating, producing extremely sturdy front optical components.