Korth Kristalle GmbH

Refractive Index


Germanium (Ge)

Properties (Ge)    
Transmission Range (50% of total transmission)   1,85 - 23 µm (Dicke 2 mm) 
Refractive Index   4,104147 @633nm 
Reflective Loss   36,04% @10 µm  
Density   5.327 g/cm3  
Melting Point   938,25°C  
Molecular Weight   72.59  
Thermal Conductivity   58.61 W/(m·K)  
Heat Capacity   310 J/(kg·K) (@0°...100°C)  
Thermal Expansion   5,9 · 10-6/K @293K  
Hardness (Mohs)   800 
Young`s Modulus   102,7 <100>  GPa 
Shear Modulus   67 GPa <100> 
Bulk Modulus   77.2 GPa  
Rupture Modulus   110 MPa  
Elastic Coefficient   C11 = 129; C12 = 48.3; C44 = 67.1 GPa  
Dielectric Constant   16.6 @f = 9.37 GHz  
Solubility in Water   insoluble  
Crystal Structure   single crystal, synthetic  
Crystal Type  cubic, diamond structure, a = 5,62 Å  
Cleavage Planes   (111), not perfect 
Poisson Ratio   0.2 
Application   lenses, band pass filters, thermography, ATR Crystals, IR optics  
Remarks   relatively inert, DLC Coating possible, max. Temp. 100°C 

Transmission spectrum


Transmission spectrum-2

Ge homepage engl

NOTICE: While we endeavour to ensure that the information on this Website is correct, we do not warrant the accuracy and completeness of the material on this Website.