Germanium optical windows are ideal for IR applications with its broad transmission range and opacity in the visible portion of the spectrum. Germanium has a high index of refraction, making it a perfect choice for applications that require low dispersion. Germanium is also commonly used in IR imaging systems typically operating in the 2 µm to 12 µm spectral range. An AR coating provides high transmission from 2 µm to 16 µm. These windows are an excellent choice for low power CO2 laser applications. Germanium is more rugged than other IR materials, but caution should be taken for high temperature applications where the material will become opaque in the IR realm as the temperature rises.