Germanium windows are optical components commonly used in various applications that require infrared (IR) transmission.
Germanium is a semiconductor material with a broad transmission range from 2-16μm, making it an ideal candidate for mid-wave infrared (MWIR) and long-wave infrared (LWIR) applications.
Its unique properties, such as durability and high optical clarity, make it an excellent choice for optical windows used in defense and aerospace, biomedical imaging, laser systems, and other infrared applications.
Lattice Materials specializes in precision manufacturing of germanium windows, while maintaining optical quality and reducing the absorption of infrared radiation.
Optical grade germanium is resistant to thermal and mechanical shock, making it suitable for IR applications that are subjected to variations in temperature and other mechanical stressors.
For example, germanium windows are used in thermal imaging systems to detect infrared radiation and enable remote thermal mapping.
Germanium IR windows or beamsplitters are also commonly used in infrared spectroscopy and for remote sensing applications that require detecting and analyzing infrared light.
While these can also be manufactured from other substrates with high transmission in the infrared spectrum, such as zinc selenide (ZnSe), magnesium fluoride (mgf2) calcium fluoride (CaF2), we prefer to use germanium because of its mechanical strength.
Crystal Structure: Diamond cubic
Index of Refraction @25℃: @3 microns, n = 4.0045
Absorption Coefficient @25℃, cm -1 @3 microns, a = 0.0047
Germanium optics provide unmatched optical clarity, making them ideally suited for a wide range of optical systems.
Germanium has low dispersion properties, allowing it to maintain the integrity of transmitted light, resulting in high optical clarity.
Atomic Density, atoms/cm3: 4.416
Lattice Constant, nm @23℃: 0.565754
Surface Tension mN/m (=dyne/cm): 650
Poisson’s Ratio 125K-375K: 0.278
Melting Point ℃: 937.4
Round or Rectangular Shapes up to 17.5″ (450 mm)
Polished to optical specifications better than 40/20 scratch/dig, 1/10th wave flatness and down to 10 Å RMS
Available as uncoated or coated
Custom thin film coatings, such as DLC and AR coating (antireflection coating) are available for increased durability.
*All specifications are dependent on part geometry.
Do you have a requirement for germanium windows? Send us your specific requirements, and our technical sales representatives will be in touch with you.
