Germanium Infrared Windows Ge Windows

Germanium is a kind of chemically inert material. Pure germanium single crystal has a high refractive index. Germanium window is transparent under infrared light, but opaque to visible light and ultraviolet light. Its transmission spectrum ranges from 2 to 12 μm. More importantly, it has a good pass rate in the 8~14μm (up to 95% or more after coating).

Because germanium (Ge) has a high Knoop hardness, it is often used in infrared systems that require higher intensity , because of its high refractive index, usually we will coat Ge with an anti-reflection coating. The commonly used bands are: 3~12um or 8~12um. When Ge windows and Ge Lenses are heated, its transmittance will decrease with the increase of temperature. That means, the best application temperature of germanium (Ge) is below 100℃. When designing a system, it is recommended that designers take into account the high-density characteristics of germanium (Ge). The ratio of the size and thickness of the lens must meet the processing ratio, and the weight must meet the design requirements. The diameter range of germanium (Ge) lenses and windows produced by our company is: 5~260mm, the surface precision can reach up to 20/10, and the surface flatness can reach: λ/10@633nm (the ratio of lens thickness to diameter must meet processing ratio).

Ge windows are widely used in infrared imaging systems and infrared spectrometer systems, and become ideal materials for CO2 laser lenses, windows, and output coupling mirrors due to their good mechanical properties and thermal conductivity. In addition, germanium can also be used as a base material for various infrared filters. OPTIC-WELL provides following types of germanium windows, Uncoated Substrate / Double Sided Anti-Reflection Coated /One Side Anti-Reflection with other Side DLC Coated. And can provide round, square and custom shape processing.