Germanium windows have become the avant-garde choice for advanced optical applications, particularly in the infrared (IR) spectrum. Their exceptional properties offer a plethora of advantages that make them highly sought after for rugged environments:

• Broad Transmission Range in Infrared (IR) Spectrum: Germanium windows boast unparalleled transparency to infrared wavelengths, spanning from 2 µm to 14 µm. This unique characteristic makes them suitable for IR laser applications, facilitating the efficient passage of IR radiation while maintaining opacity to UV and visible light. The broad transmission range also makes them ideal for various IR applications, including thermal imaging.
• Minimal Chromatic Aberration and Low Dispersion: Germanium windows exhibit low dispersion, resulting in minimal chromatic aberration. This ensures superior image quality and reduced color distortion, making them ideal for applications that necessitate precise optical performance, such as weight-sensitive systems requiring accurate imaging.
• High Index of Refraction and Anti-Reflection Coating: With a high index of refraction measuring 4.0 from 2 – 14 µm, germanium is an excellent candidate for anti-reflection coatings. These coatings optimize light transmission by reducing undesirable reflections that could compromise optical system efficiency. Anti-reflection coatings like BBAR (Broadband Anti-Reflection) coatings enhance germanium optical windows’ performance, ensuring maximum transmission properties.
• Robustness and Durability in Harsh Environments: Germanium boasts a Knoop Hardness of 780, nearly twice that of MgF, making it renowned for exceptional hardness and durability. This makes it the preferred choice for applications that demand rugged optics capable of withstanding harsh environmental conditions. In weight-sensitive systems, the robustness of germanium lenses allows for the creation of high-density and compact optical systems without compromising performance.

Factory Standard?

• Germanium Window with different sizes (2 mm – 100 mm)
• Diameter: +0/-0.05 mm
• Thickness: +0.01/-0.03 mm
• Flatness: 1/2 Lambda
• Parallelism: < 3 arc min
• Polished surface finish:20-10 (no dig)
• Bevel: protective bevel
• Transmission rate: >47.5%@3.7-4.8um or according to customer’s specifications