Germanium Windows are excellent for infrared spectrum applications because of their broad IR transmission range and opacity in the visible portion of the spectrum. Germanium offers broadband transmission across a wide range of infrared wavelengths from 2 µm to 14 µm, in particular in the mid-wave infrared (MWIR) and long-wave infrared (LWIR) regions, which in unite with low dispersion, making it well-suited for applications requiring distant and precise infrared imaging and sensing. Ge windows are more rugged than other infrared (IR) materials, it is often used as protective windows for thermal cameras, or long-pass filters for wavelengths above 2000nm. Germanium also has the virtues of high chemical inertness. But germanium would begin to become opaque in the IR spectrum when the temperature rises above 90℃, one should take caution when it is used in high-temperature applications.

Shanghai North Optics offers both off-the-shelf and custom Germanium Windows, the maximum diameter is 300mm. For the off-the-shelf germanium windows, transmission curves and specifications are individually listed. Because Germanium has a considerably large refractive index, AR coatings are crucial to ensure high transmission. Coating options available include DLC (Diamond Like Carbon) coating, AR@3-5 micro, AR@8-12 micro, and BBAR@3-12 micro, North Optics is capable of fabricating the Germanium optical windows with high precision and coating sets according to your requests.