ISP Optics Germanium (Ge) Windows provide transmission and low absorption through the Long-Wave Infrared (LWIR) spectrum, making it useful for thermal imaging applications. Germanium features a Knoop Hardness of 780, making it ideal for infrared applications requiring rugged optics. These windows are available uncoated, Broadband Anti-Reflection (BBAR) coated for 8 – 12µm, or Diamond-Like Carbon (DLC) coated for 8 – 12µm. ISP Optics Germanium Windows are ideal for integration into thermal imaging systems, especially those that require rugged optics. Germanium is subject to thermal runaway, meaning that the transmission decreases as temperature increases. As such, these germanium windows should be used at temperatures below 100°C.