Germanium lenses

13 Jan 2025

Germanium lenses are durable, corrosion-resistant optical lenses ideal for harsh environments, thermal imaging systems, and precision instruments. With a high refractive index and low dispersion, they minimize chromatic aberration and excel in infrared applications, including FLIR and FTIR systems. 

Shanghai Optics offers a wide range of germanium lenses, including spherical, aspheric, and custom options, with anti-reflective coatings that enhance transmission up to 95%. These lenses provide optimal transmission (over 45%) in the 2-12 μm range, making them perfect for mid-infrared light. 

Germanium's ruggedness comes from its Knoop hardness of 780, though its high density (5.33 g/cm³) requires consideration for weight-sensitive designs. However, germanium lenses are temperature-sensitive due to thermal runaway, limiting their use to below 100°C. With versatile configurations and specialized coatings, germanium lenses are a robust choice for demanding optical systems.

Germanium Optics Factory Standards

• Substrate Material: Ge (Germanium)
• Diameter:  5mm-350mm
• Shape: Spherical Plano-Concave, P-Convex, Concave-Convex or Aspheric
• Focal length: +/-1%
• Surface Quality: 20-10 (after coating)
• Surface figure: l/4 @ 633nm
• Clear Aperture: >85% of central dimension
• Antireflection Coating: @ 3-12 um

Contact us for manufacturing limit or custom specifications.