Ge lenses & windows
2020-06-24
Monocrystal Germanium is a most widely used infrared material for windows and optical elements in thermal-imaging systems and IR spectrograph systems in the 2 to 12 microns waveband. It has excellent hardness and high thermal conductivity, and it is insoluble in water.
Due to its good mechanical property, good thermal conductivity, and the low absorption in 10.6 micron, monocrystal germanium is an ideal substrate material for CO2 laser lenses, windows and output couplers for low-power CW as well as IR filters.
Optical Properties:
Symbol | Ge |
Atomic Number | 32 |
Melting Point (℃) | 937 |
Density (g/cm3) | 5.33 |
Thermal Expansion Coefficient (10-6, ℃-1) | 6.1 |
Youngs Modulus (Gpa) | 103 |
Rupture Modulus(Mpa) | ≥75 |
Poisson’s Ratio | 0.28 |
Material specifications:
Purity | > 99.9999% |
Crystal Structure | Monocrystalline & Polycrystalline |
Conductive Type | N-type |
Orientation | |
Typical Resistivity | 5-40 Ohm-cm |
(Germanium with lower resistivity can be also provided according to your request)
Specifications:
Germanium lenses:
Diameter or length tolerance | Up to +0/-0.01mm |
Central thickness tolerance | Up to +/-0.01mm |
Surface figure | Up to λ/10 @632.8nm |
Centration | Up to 5 arc seconds |
ETV | ≤0.02mm |
Surface quality | Up to 10-5 Scratch & Digs |
Clear aperture | Up to 100% of the diameter |
Bevel | <0.2mmx45° |
Coating | According to your request |
Germanium windows:
Diameter or length tolerance | Up to +0/-0.01mm |
Thickness tolerance | Up to +0/-0.01mm |
Surface figure | Up to λ/20 @632.8nm |
Parallelism | Up to 0.5 arc seconds |
Surface quality | Up to 10-5 Scratch & Digs |
Bevel | <0.2mmx45° |
Coating | According to your request |
