Oxygen-free optical glasses


Oxygen-free infrared optical glasses are intended for the manufacture of parts for devices operating in the wavelength range of 0.7–17 µm.

The shift of the edge of the fundamental absorption bands to the infrared spectral range is due to the replacement of oxygen in the glass composition by its analogs (sulfur, selenium, tellurium).

Oxygen-free infrared optical glass code IKS25

Application area

Oxygen-free infrared optical glass intended for the manufacture of optical elements (windows, prisms, lenses, filters) of optical infrared devices, thermal imagers for medical and technical purposes, biological and environmental monitoring systems operating in the wavelength range of 1.5 ÷ 17 microns.

Спектральные кривые коэффициента пропускания образцов стекла ИКС25 толщиной 2 и 10 мм. Пунктиром показана кривая собственного излучения стекла ИКС25 при температуре 160oС.

Spectral characteristics

Wavelength, micrometers Transmission, % (at samples thickness of 10 mm) Attenuation rate, cm-1
2,0 0,56 0,05
3,0 0,60 0,02
4,0–12,0 0,61 0,02
14,0 0,43 0,16
16,0 0,43


Characteristic Value
Transparency range 1.5÷17  μm
Refractive index for the wavelength of 2 μm 131
Refractive index for the wavelength of 10 μm 152
Density 4.72 g/cm3
Elastic modulus 19 GPa
Glass transition temperature, Tg 150 oC
Softening point 190 oC
Coefficient of linear thermal expansion ᾳ × 107 from -60 to +20 °C 197
Coefficient of linear thermal expansionᾳ × 107from +20 °C to Tg 220
Maximum operating temperature 100 оС
Blank size 25–300 mm a

a — the ratio of the diameter or diagonal of the glass blank to its thickness from 3: 1 to 10: 1 providing that the thickness is of at least 5 mm