Germanium Windows and Ge Wafers

Our Germanium Windows are designed with three specialized anti-reflection coating options to meet diverse application needs:

• 3 – 5μm Coating: Tailored for mid-infrared applications.
• 3 – 12μm Coating: Suitable for broadband multispectral systems.
• 8 – 12μm Coating: Optimized for thermal imaging applications.

Given its high refractive index, an anti-reflection coating is highly recommended to ensure efficient light transmission. Germanium is prone to thermal runaway, where its transmission efficiency declines as the temperature rises. Therefore, these windows are best utilized at temperatures below 100°C. The material’s high density (5.33 g/cm³) should be taken into account when designing systems sensitive to weight. With a Knoop Hardness of 780 kg/mm², nearly twice that of magnesium fluoride, germanium is exceptionally durable and well-suited for rugged infrared optical applications.

Key Features of Germanium Windows

• Ideal for mid-infrared, broadband multispectral, and thermal imaging applications.
• Anti-reflection coatings enhance transmission efficiency.
• Operates effectively below 100°C to avoid thermal degradation.
• High density and hardness make it robust yet lightweight-sensitive.

PICTURE SHOW OF OUR DIAMETER 60MM THICKNESS 5MM WINDOWS/GE WAFERS

Properties 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 (n_d): 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