Gallium Arsenide, GaAs, Gallium Arsenide Transmission

Gallium Arsenide used for lenses and beam splitters provides an alternative to ZnSe in medium and high power CW CO₂ laser systems. It is most useful in applications where toughness and durability are important. Its hardness and strength make it a good choice where dust or abrasive particles tend to build up on or bombard the optical surfaces. When frequent cleaning by wiping is required, GaAs is excellent. The material is nonhygroscopic, safe to use in laboratory and field conditions and is chemically stable except when in contact with strong acids.
Maximum standard diameter is 4", sizes up to 150 mm diameter x 30 mm thickness are available on request.

Chemical Formula	GaAs
Molecular Weight	144.63
Density, g/cm³ at 300 K	5.32
Absorption Coefficient, 1/cm at 10.6 µm	<0.02
Useful Transmission Range, µm	1-11
Reflection Losses, % for 2 surfaces at 12 µm	45
Dielectric Constant at 300 K, high frequency	10.88
Dielectric Constant at 300 K, static	12.85
Melting Point, K	1511
Thermal Conductivity, W/(m K) at 300 K	55
Thermal Expansion, 1/K at 300 K	5.7 x 10^-6
Specific Heat, cal/(g K) at 273 K	0.076
Debye Temperature, K	360
Knoop Hardness, kg/mm²	731
Young's Modulus, GPa	82.68
Bulk Modulus, GPa	75.5
Poisson Ratio	0.31
Bandgap, eV	1.4
Solubility in water	None

Wavelength, µm	8.0	10.0	11.0	13.0	13.7	14.5	15.0	17.0	19.0	21.9
Refractive Index	3.34	3.13	3.04	2.97	2.89	2.82	2.73	2.59	2.41	2.12