AMTIR-1

AMTIR-1 is a “glass like” amorphous material with a high homogeneity, that is able to transmit in the infrared. AMTIR-1 is used for infrared windows, lenses, and prisms, when transmission in the range of .75-14µm is desired. AMTIR-1 is not water soluble. The low thermal change in refractive index (72 x 10-6/°C) is an advantage in lens design to prevent defocusing. The upper use temperature is 300°C.


AMTIR-1’s composition of Ge33As12Se55 makes it somewhat similar to Germanium in its mechanical and optical properties. It is nearly as dense as Germanium but has a lower index of refraction, making it a good option for color correction with Germanium in an optical system. AMTIR-1 performs especially well in the 8-12µm spectral region where its absorption and dispersion are the lowest. AMTIR-1 optical grade material is generally more expensive than Germanium.

 

Property Specification
Transmission Range 0.75µm to 14.0µm
Density 4.4 g/cm3
Thermal Expansion 12 x 10-6 / °C
Surface Finish Typical specifications for surface quality in the infrared are 40-20 or 60-40 scratch-dig in the 1 to 7µm spectral region & 60-40, 80-50 or 120-80 scratch-dig for the 7-14µm area, depending upon system performance requirements. Diamond Turned surface finishes of 120 Å rms or better are typical.
Surface Figure In the infrared, typical required surface figure ranges from 1/2 wave to 2 waves @ 0.6328µm depending on the system performance requirements.
AR Coating Options Mostly BBAR coated for use in the 3-5µm or 8-12µm spectral regions. Many other specialized coating bands are possible between 1 & 14µm.
Typical Applications Thermal imaging, FLIR, YAG laser systems.
Products Manufactured Lenses, Aspheric Lenses, Binary (Diffractive) Lenses, Windows, Wedges, Prisms.

 

Wavelength (µm)
Index of Refraction (n)
1.0
2.606
2.00
2.531
3.00
2.519
4.00
2.514
7.00
2.506
10.00
2.498
14.00
2.483