At Photonic Sense, we grow all our Germanium ingots via the Czochralski or "Cz" crystal pulling method. The crystal structure can be either mono or poly. We offer two grades, which include Standard Optical and EXPT. You can choose from three surface finishes, Standard, Fine and Superfine. Additional information on Physical and Optical properties, Material specifications, Shapes and Sizes, Tolerances, and Surface Quality are given below. Product data sheet of our Germanium    [Printer-Friendly] Physical Properties[1]   Melting Point 938.25oC Density 5.323 g/cm3 Thermal Expansion Coefficient 5.7 x 10-6/K Youngs Modulus <111> 155.6 GPa Modulus of Rupture 72.4 MPa     Optical Properties[2] Refractive Index     Dn/dT   4.14 x 10-4/°K @ 5.2µ Transmission           Material Specifications   Purity > 99.999% Crystal Structure Monocrystalline & Polycrystalline Type/Dopant N/Antimony; P/Boron Orientation <111> Resistivity 0.5 - 40 /cm Standard Optical Grade 5.0 - 40 /cm EXPT Grade 0.5 - 5.0 /cm EXPT Grade has specific enhanced properties for applications where electromagnetic shielding is required.       Products Rods and Discs 10 - 500 mm   Plano Optics 10 - 500 mm; 350 x 350 mm Lenses 10 - 500 mm Rectangular and other shapes 350 x 350 mm; max. 500 mm diagonal Witness samples and wedges 25.4 mm ; 1 - 10 mm thick       Tolerances Tolerances are diameter dependent , and they are based on a 10 mm minimum to 500 mm maximum. Fabrication is according to DIN 286-2 (1990-11) and ASME Y14.5M 1994. Tighter tolerances are available upon request.   Diameter ± 0.2 mm to ± 1.5 mm Thickness ± 0.1 mm to ± 0.8 mm Flatness ± 30’ Parallelism ≤ 25 µm Perpendicularity ≤ 30 µm Chamfer 0.1 to 1.6 mm ETV ≤ 30 µm Roundness ≤ 30 µm Length and Width ± 0.05 mm       Surface Quality As cut     Standard D46 Rq = 2 μm max. Fine D15 Rq = 0.8 μm max. Superfine D7 Rq = 0.2μm max. Polished       S/D: 60/40 or better   Flatness: 5 fringes   Irregularity: 2 fringes   Parallelism: 0.01 mm       Rq is defined as RMS deviation of all peaks/valleys to surface. Polishing provided for filters and witness samples only.       Quality Assurance     Full traceability according to MIL 130 Standard back to Melt / Lot       [1] Taken from NIST Database [2] Measured by Photonic Sense	Germanium Data Sheet More About Germanium Silicon Data Sheet More About Silicon
©2007 Photonic Sense