Germanium - bring minimal chromatic aberration.

Ge shows good transmission in 2-15μm range. Attributed to its high refractive index making low dispertion, the lens made of Ge brings minimal chromatic aberration and is very popular for IR systems operating in the 3-5 or 8-12μm spectrum. Ge is also good electromagnetic interference (EMI) shielding material. The EMI grade Ge windows with low resistance of 4-6 ohms is able to shield against electromagnetic interference within millimeter and centimeter ranges, make the IR system show better performance.
Ge blocks UV and visible light, as well as IR up to 2μm. Its density 5.323 gram/mm³ is highest in the IR transmitting materials, these properties limit it to be used in visible or NIR light combination and weight restricted systems.  
U-Optics offer Ge optical components made of monocrystalline up to 250mm and polycrystalline up to 300mm aperture, for infrared thermal imaging, pyrometry, spectroscopy and laser optics applications. Please contact our Sale & Support team to discusss your detailed request on Germanium optics.

Key Figures
  • High index of refraction (around 4.0 from 2-14μm).
  • Electromagnetic interference (EMI) shielding.
  • Short-wave cutoff at 2μm.
  • Highest density among common IR materials.
  • Components dimension available up to 300mm.


 U-Optics provides following optical components fabricated by Germanium.


Ø  Spherical lens, Aspherical lens, Diffractive aspherical lens

Ø  Prisms, ATR prisms, Wedges

Ø  Beamspliters

Ø  Windows

Ø  Mirrors

Ø  Filters for IR detectors

Ø  Other customs optics




Ø  Clear Aperture                              90%

Ø  Dimension Tolerance                +0/-0.2mm

Ø  Thickness Tolerance                  ±0.2mm

Ø  Surface Quality                             60/40

Ø  Surface Accuracy                         1λ @ 10.6μm

Ø  Parallelism                                   < 3 arc minutes

Ø  BBAR Coating                              R avg < 2% per surface @ 3-5μm

                                                             R avg < 2% per surface @ 8-12μm