Intrinsic Crystal Technology Co., Ltd - manufacturer of Germanium windows and Germanium lenses for Thermal Imaging Applications, Infrared Spectroscopy and Remote Sensing.
Germanium windows up to 180 mm diameter;
Germanium planoconvex and meniscus lenses with any focal length;
Custom Germanium Optics with DLC or BBAR coating 2-14µm, 8-12µm;
Bandpass filters (IR filters on Germanium substrate).
Contact our Sales Team for pricing for any custom size and coatings requirements. Special prices on large diameter Ge optics!
Alkor is one of the largest Russian manufacturer of Germanium optics with 25 years experience. Our Germanium windows, wedges and lenses are widely used in IR sensors, LIDARs, thermal image and medical applications, in pyrometry and thermography, FLIR cameras all over the world.
Germanium transmission curve. Window thickness 10mm.
Germanium is used widely for lenses and windows in thermal imaging, FLIR applications, as germanium viewports. Its high index of refraction (about 4) makes it of particular interest
Useful transmission range of Germanium windows is from 2 to 13µm. Germanium is opaque in the visible. Germanium has the property of thermal runaway, meaning that the transmission decreases as temperature increases. As such, Germanium window should be used at temperatures below 100°C.
The Knoop Hardness of Germanium (780) is approximately twice that of Magnesium Fluoride, making it ideal for IR applications requiring rugged optics. Germanium's high density (5.33 g/cm^3) should be considered when designing for weight-sensitive systems.
Custom germanium windows and germanium lenses are available in any size and configuration. Anti-reflection coatings can be applied for 2-14µm or 8-12µm (BBAR coating or DLC/BBAR) depending on your custom application.
Germanium properties |
Chemical Formula | Ge |
Crystal Form | Monocrystal |
Crystal Class | Cubic |
Resistivity, Ohm*cm | 5-40 |
Lattice Constant, Е | 5.66 |
Molecular Weight | 72.60 |
Density, g/cm3 at 300 K | 5.33 |
Dielectric Constant for 9.37 x 109 Hz at 300 K | 16.6 |
Melting Temperature, K | 1210 |
Thermal Conductivity, W/(m K) at 293 K | 59 |
Thermal Expansion, 1/K at 298 K | 6.1 x 10-6 |
Specific Heat, cal/(g K) at 273-373 K | 0.074 |
Debye Temperature, K | 370 |
Bandgap, eV | 0.67 |
Solubility in water | None |
Knoop Hardness, kg/mm2 | 800 |
Mohs Hardness | 6.3 |
Young's Modulus, GPa | 102.66 |
Shear Modulus, GPa | 67.04 |
Bulk Modulus, GPa | 77.86 |
Poisson's Ratio | 0.278 |
Ge Lens, Germanium Lenses SpecificationsMaterial | Germanium |
Wavelength Range | 2.0 - 16.0 μm |
AR Coating Range | 8-12 μm |
Reflectance over Coating Range (Avg.) | <1.5% |
Damage Threshold | 0.5 J/cm2 (10.6 µm, 100 ns, 1 Hz, Ø0.478 mm) |
Diameter Tolerance | +0.00/-0.10 |
Thickness Tolerance | ±0.2 mm |
Focal Length Tolerance | ±1% |
Surface Quality (Scratch-Dig) | 60-40 |
Surface Flatness (Plano Side) | λ/2 |
Spherical Surface Power (Convex Side)* | 3λ/2 |
Surface Irregularity | λ/2 |
Centration | ≤3 arcmin |
Clear Aperture | 80% of Diameter |
Design Wavelength | 10.6 μm |