Infrared Optics

Optir-1™ (Equivalent to AMTIR 1 and IG2)
Composition	Ge₃₃As₁₂Se₅₅
Density	4.41 g/cm³
Thermal expansion	12.1x 10⁶/K
Specific Heat	0.33 J/gk
Thermal conductivity	0.24 W/mK
Transition temperature	368°C
Knoop hardness	1.41 GPa
Modulus of rupture	19 MPa
Young's modulus	21.5 GPa
Shear modulus	8.9 GPa
Dispersion	202 (4 µm) 108 (10.6 µm)
Thermo-optic coefficient dn/dT	71x10⁶/K(3,4 µm) 60x10⁶/K(10,6 µm)

Optir-3™ (Equivalent to AMTIR 3 and IG5)
Composition	Ge₂₈Sb₁₂Se
Density	4.66 g/cm³
Thermal expansion	14.0x 10⁶/K
Specific Heat	0.33 J/gk
Thermal conductivity	0.25 W/mK
Transition temperature	385°C
Knoop hardness	1.13 GPa
Modulus of rupture	18 MPa
Young's modulus	22.1 GPa
Shear modulus	8.5 GPa
Dispersion	180 (4 µm) 102 (10.6 µm)
Thermo-optic coefficient dn/dT	76x10⁶/K(3,4 µm) 91x10⁶/K(10,6 µm)