Ge crystal

Product Properties

Germanium
Refractive Index(@10μm)	4.0026
Homogeneity of Refractive Index	≦1.0×10-4 （Φ250mm）
Bulk Absorption Coefficient(@10μm,cm-1)	≦0.03
Rupture Modulus(Mpa)	≧75

Technical Index

Germanium
Transparent region (μm)	1.8—23
Hardness (kg/mm2 )	800
Density(g/cm3)	5.33
Yonug’s Modulus(Gpa)	103
Thermal Conductivity(Wcm-1k-1)	59
Thermal Expansion Coefficient(/℃)	6.1×10-6
Posson ratio	0.28
Melting point(/℃)	937
Specific heat (Cal/g.k.)	0.074
Dielectric constant	16
Resistivity (Ωcm)	0.01–50

the listed index are from reference book, may be different from our products, more special requirements should be discussed individually.

Specification

Monocrystalline and polycrystalline cylinder blanks
Largest Diamester(mm)	300（mono-crystalline） 380（polycrystalline）
Tolerance on diameter	standard 0.1mm; limit 0.03mm
Thickness	minimum 0.8mm,maximum: depends on the diameter,
Example	for Φ25mm，max length 600mm; Φ200mm,max.length 200mm
Tolerance on thickness	Standard:0.1mm,limit:0.05mm(thickness ≦40mm)
Monocrystalline and polycrystalline rectangular blanks
Maximum dimensions	200*200mm
Tolerance on these dimensions	0.1mm
Minimum thickness	depend on the dimensions，example for diagonal≦150mm，thickness≧2mm；
Tolerance on thickness	standard 0.1mm(thickness≦100mm)
Spherical generated lens
Diameter	from 15 to 200mm
Tolerance on diameter	standard 0.1mm; limit 0.03mm
Tolerance on curvatures	standard0.5%; limit 0.05%
Tolerance on center thickness	standard0.1mm; limit 0.05mm
Special shapes
Monocrystalline and polycrystalline prisms Monocrystalline and polycrystalline tapers

This table just show the general specification of our products, more special requirements could be discussed individually.