Germanium wafer D30mm

Germanium Windows and Ge Wafers are key components in advanced optical systems, offering exceptional performance across various infrared applications. These windows come with three specialized anti-reflection (AR) coating options: 3–5μm for mid-infrared uses, 3–12μm for broadband multispectral tasks, and 8–12μm tailored for thermal imaging. For example, the Ge wafer depicted in the image has a diameter of 55mm, a thickness of 1mm, and is coated on both sides with an AR layer optimized for 7–14μm wavelengths, achieving an average transmission (Tavg) greater than 95%.

Germanium’s high refractive index necessitates AR coatings to maximize light transmission. However, its susceptibility to thermal runaway—where transmission drops as temperatures rise—limits its use to environments below 100°C. Its relatively high density (5.33 g/cm³) must also be factored into designs for weight-sensitive applications. On the other hand, Germanium’s impressive Knoop Hardness of 780—nearly double that of magnesium fluoride—ensures durability and resistance to scratches, making it ideal for rugged optical systems operating in harsh conditions. These unique properties position Germanium Windows and Ge Wafers as critical solutions for precision-driven infrared technologies.

Picture show of our Windows/Ge wafers

Property of Germanium

• Clear Aperture (%): 90.00
• Dimensional Tolerance (mm): +0.0/-0.1
• Coefficient of Thermal Expansion CTE (10-6/°C): 6.1
• Density (g/cm3): 5.33
• Index of Refraction nd: 4.002 @ 11µm
• Knoop Hardness (kg/mm2): 780.00
• Parallelism (arcmin): <1
• Poisson’s Ratio: 0.28
• Substrate: Germanium (Ge)
• Surface Quality: 60-40
• Thickness Tolerance (mm): ±0.1