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Germanium(Ge) window

Germanium(Ge) optical window
Material	Single crystal of Germanium(Ge)
Other Names	Germanium window substrate, Ge window, Germanium IR window
Crystal structure	Cubic
Applicable wave band	2μm ~ 14μm
Melting Point	936℃
Operating temperature	<100℃
Crystal properties	Orientation: <111> Conductivity type: N-type Resistivity: 5-40 Ohm-cm
Density	5.33 g/cc
Refractive index	4.0026 at 11 μm
Absorption coefficient	≤0.027 /cm at 10.6μm
Thermal conductivity	58.61 W/mK at 293K
Knoop Hardness	780
Thermal expansion coefficient	6.2×10^-6/℃ at 298K
Maximum size	Diameter 250mm (Single crystal)

Material	Standard Size	Surface quality
Germanium(Ge) window	φ10.0mm x 1.0mm φ25mm x 1.0mm φ25.4mm x 3.0mm φ25.4mm x 5.0mm φ50mm x 1.0mm φ50.8mm x 3.0mm 12.7 x 12.7 x 3.0mm 25.4 x 25.4 x 3.0mm Or others	Polishing: Double side optical polished or Epi-polished Roughness: Ra<1.5nm or Ra 5~10nm, Ra<0.5nm, Size Tolerance: +/-0.1mm Thickness Tolerance: +/-0.1mm or +/-0.05mm Parallelism: 1 minute, 30 seconds, 5 seconds or higher Surface Finish: 60-40, 40-20, 20-10 (scratch-dig) Surface Figure: 1/2λ, 1/4λ or higher Chamfer: 0.25mm × 45° Coating: Upon requirements

Silicon windows and Germanium windows are the most commonly used Infrared(IR) windows. The best working wavelength of Silicon windows is 3-5um, and the best working wavelength of Germanium windows is 2-14um. It is one of the best substrate materials for filters.

Germanium has good thermal conductivity and a high epinuclear hardness and strength, it is often used in Infrared systems that require higher strength. Due to its high refractive index, an Antireflection(AR) coating is usually required to improve the transparency of Germanium windows, its commonly used wave bands are: 3~12um or 8~12um. The transmission properties of Germanium are extremely sensitive to temperature changes. The higher the temperature and the lower the transmittance. The best Operating temperature of Ge window is <100 ℃.

Germanium windows have higher hardness than Magnesium fluoride(MgF2) windows and can be used in the field of optoelectronics, Infrared thermal imaging cameras, Infrared laser systems, Infrared optical instruments, Infrared optics, etc.

We can customize different size and thickness of Germanium(Ge) optical window upon requirements, such as Germanium(Ge) round wafer, Square substrate and Cylinder, or Punch holes and other shapes.

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BIOTAIN CRYSTAL CO., LIMITED
Tel: (+86) 1506 0796 451
Fax: (+86) 0597 2212602
Email: sales@crystal-material.com
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Main office: A7, No. 501, Denggaoxi Road, Xipi street, Xinluo District, Longyan, Fujian, China

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Germanium(Ge) window

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