021 51012729
info@bbotech.com
Related link: ZnSe Windows and Lenses 
ZnSe Characteristics & Transmission Curve
Zinc Selenide is used for infrared windows, lenses, and prisms where transmission in the range 0.63µm to 18µm is desired. Zinc Selenide has a very low absorption co-efficient and is used extensively for high power infrared laser optics. It is non-hygroscopic.
Zinc Selenide is a relatively soft material and scratches rather easily. The low absorption of the material avoids the thermal runaway problems of Germanium. Zinc Selenide requires an anti-reflection coating due to its high refractive index if high transmission is required. ZnSe has a fairly low dispersion across its useful transmission range.
Zinc Selenide, a chemically vapor deposited material, is the material of choice for optics used in high power CO2 laser systems due to its low absorption at 10.6µm. However it is also a popular choice in systems operating at various bands within its wide transmission range. ZnSe has a high resistance to thermal shock making it the prime material for high power CO2 laser systems. ZnSe however is only 2/3 the hardness of ZnS multi-spectral grade but the harder anti-reflectance coatings do serve to protect ZnSe. Zinc Selenide’s cost is about the same as ZnS multi-spectral grade and is generally more expensive than Germanium.
|
Property |
Specification |
|
Transmission Range |
0.6µm to 16µm |
|
Density |
5.27 g/cm3 |
|
Thermal Expansion |
7.1 x 10-6 /K @ 273K, 7.8 x 10-6 /K @ 373K, 8.3 x 10-6 /K @ 473K |
|
Surface Finish |
Typical specifications for surface quality in the infrared are 40-20 or 60-40 scratch-dig in the 0.8 to 7µm spectral region & 60-40, 80-50 or 120-80 scratch-dig for the 7 to 16µm area, depending upon system performance requirements. Diamond Turned surface finishes of 150 Å rms or better are typical. |
|
Surface Figure |
In the infrared, typical required surface figures range from 1/2 wave to 2 waves @ 0.6328 µm depending on the system performance requirements. |
|
AR Coating Options |
Typical available coatings for ZnSe include BBAR for 0.8 to 2.5µm, 3 to 5µm, 1 to 5µm, 8 to 12µm, & the 3 to 12µm spectral regions & single wavelength coating AR at 10.6µm. Many other specialized wavelength bands are possible within the 0.6 to 16µm range. |
|
Typical Applications |
CO2 laser systems, Thermal imaging, FLIR, Astronomical, Medical |
|
Products Manufactured |
Lenses, Aspheric Lenses, Binary (diffractive) Lenses, Windows, Optical Beamsplitters, Optical Filters, Prism. |
|
Wavelength (µm) |
Index of Refraction (n) |
|
1.0 |
2.4890 |
|
3.0 |
2.4380 |
|
4.0 |
2.4330 |
|
5.0 |
2.4300 |
|
7.0 |
2.4220 |
|
9.0 |
2.4120 |
|
10.6 |
2.4028 |
|
11.0 |
2.4000 |
|
13.0 |
2.3850 |
|
15.0 |
2.3670 |
|
17.0 |
2.3440 |
