PRODUCTS & SERVICES

PRODUCTS & SERVICES

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

图片-11.jpg

 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


+86-10-6212-9087