|
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
|
|
