Germanium window, germanium lens, optical lens

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&nb

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Germanium Windows, Germanium Lenses, Optical Lens
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 FormulaGe
Crystal FormMonocrystal
Crystal ClassCubic
Resistivity, Ohm*cm5-40
Lattice Constant, Е5.66
Molecular Weight72.60
Density, g/cm3 at 300 K5.33
Dielectric Constant for 9.37 x 109 Hz at 300 K16.6
Melting Temperature, K1210
Thermal Conductivity, W/(m K) at 293 K59
Thermal Expansion, 1/K at 298 K6.1 x 10-6
Specific Heat, cal/(g K) at 273-373 K0.074
Debye Temperature, K370
Bandgap, eV0.67
Solubility in waterNone
Knoop Hardness, kg/mm2800
Mohs Hardness6.3
Young's Modulus, GPa102.66
Shear Modulus, GPa67.04
Bulk Modulus, GPa77.86
Poisson's Ratio0.278
Germanium Windows, Germanium Lenses, Optical Lens
Ge Lens, Germanium Lenses  
Wavelength Range2.0 - 16.0 μm
AR Coating Range8-12 μm
Reflectance over Coating Range (Avg.) <1.5%
Damage Threshold0.5 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 Irregularityλ/2
Centration≤3 arcmin
Clear Aperture80% of Diameter
Design Wavelength10.6 μm

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