Gallium Arsenide (GaAs)

Optical grade Gallium Arsenide is an infrared transmitting, semi-insulating material. Special Properties: Gallium Arsenide is nearly as hard, strong and dense as Germanium. It is commonly used in applications where toughness, and durability are of great importance. It has a low absorption coefficient of 0.01cm–1 from 2.5 to 12µm. GaAs optical grade material is generally more expensive than Germanium and ZnSe. GaAs is Diamond Turnable.

 

Property Specification
Transmission Range 2µm
to 15µm
Density 5.31
g/cm3
Thermal Expansion 6 x 10-6/°K
Surface Finish Typical specifications for surface quality in the infrared are 40-20 or 60-40 scratch-dig in the 2 to 7µm spectral region & 60-40, 80-50 or 120-80 scratch-dig for the 7-15µm area, depending upon system performance requirements.
Surface Figure In the infrared, typical surface figure ranges from 1/2 wave to 2 waves @ 0.6328µm depending on the system performance requirements.
AR Coating Options Typical available coatings for GaAs include a BBAR for 3 to 5µm spectral region, & a BBAR for the 8 to 12µm spectral region. Many other specialized bands are possible within the 2 to 15µm spectral region.
Typical Applications Thermal imaging, CO2 laser systems, FLIR
Products Manufactured Lenses, Aspheric Lenses, Windows, Wedges.

 

Wavelength (µm)
Index of Refraction (n)
4.0
3.307
10.0
3.278
14.0
3.251