25.4mm Diameter Protected Germanium GE Windows With Customized Size

Basic Information
Place of Origin: Wuhan,China
Brand Name: Wuhan Siwer Optics
Minimum Order Quantity: 1 pieces
Price: 25-100USD/piece
Packaging Details: 1.Tissue paper. 2.Plastic foam packaging film. 3.Hard carton box with quakeproof filler
Delivery Time: 3-5 weeks
Payment Terms: T/T, Western Union
Supply Ability: 3000 pieces/month
Detail Information
Material: Single Crystal Germanium Size Tolerance: +/-0.1mm
Chamfer: 0.2-0.5mm Surface Quality: 40/20
Surface Flatness: Lambda/4 Parallelism: 0.01mm
Standard Coating: AR/DLC@8-14um Or Customized Density: 5.33g/cm3
Usage: Infared System Protected Window Clear Aperture: 90%
High Light:

ir window


infrared system protectd window

Product Description

Infrared Germanium window

The transmittance range of the optical germanium material is 2-14 um, and the refractive index is as high as 4. Germanium lens and germanium window are widely used in thermal imaging system.
Germanium window is a common protective window in infrared imaging system. Its material quality, surface smoothness, parallelism, surface quality and coating quality will directly affect the imaging effect.
The resistivity of optical grade single crystal germanium material we choose is usually 5-40 Ohms. If the customer requests, we can also choose germanium material with specified resistivity.
Due to the high refractive index and high surface reflectivity of germanium (r > 30%), optical germanium windows usually need AR coating on its surface.
If the equipment is used in a bad environment, the outer side of the germanium protection window needs to be coated with DLC Coating.DLC Coating has excellent wear resistance, acid resistance and corrosion resistance.

Optical Properties of Germanium Window

Material Single Crystal Germanium
AR Coating Range 3-5um,8-12um,3-11um
Reflectance over
AR Coating Range @ 0° AOI

Ravg < 2%,3-5um or 8-12um


Transmission over
AR Coating Range @ 0° AOI
Tavg > 94%,3-5um or 8-12um
Diameter Tolerance +0.0/-0.1 mm
Thickness Tolerance ±0.1 mm
Parallelism 3 arc min
Surface Quality 60-40 Scratch-Dig
Surface Flatness
(Plano Side)
λ/2 at 633nm
Surface Irregularity
(Peak to Valley)
λ/2 at 633nm
Clear Aperture >Ø10.16 mm (Ø1/2" Lenses)
>Ø20.32 mm (Ø1" Lenses)
Design Wavelength 10.6 μm


Transmittance of Antireflection coatings:

25.4mm Diameter Protected Germanium GE Windows With Customized Size 025.4mm Diameter Protected Germanium GE Windows With Customized Size 1

25.4mm Diameter Protected Germanium GE Windows With Customized Size 225.4mm Diameter Protected Germanium GE Windows With Customized Size 3

Germanium properties:

Chemical Formula Ge
Crystal Form Poly or Single Crystal
Crystal Class Cubic
Resistivity, Ohm*cm 0.01-40
Lattice Constant, Å 5.66
Molecular Weight 72.6
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


Production process

25.4mm Diameter Protected Germanium GE Windows With Customized Size 4



Infrared Elements Selection Guide

25.4mm Diameter Protected Germanium GE Windows With Customized Size 5

 What's the way of shipping?
 We accept DHL, Fedex, TNT, UPS, SF, EMS etc. If you have your own express account, it's great.

 How to pay?

 (1) T/T, PayPal, West Union,etc

 (2) Bank Fee: West Union-USD30.00(≤USD3000.00),

 T/T-USD20.00+, PayPal-5%. Please consult the local bank.

 What's the deliver time?
 For inventory: the delivery time is around 5 workdays.

 Customized products: the delivery time is 10 to 30 workdays. According to the quantity and precision.

 Can I customize the products based on my need?
 Yes, we can customize the material, specifications and optical coating for your optical components 

 based on your needs. OEM is available.




Contact Details