UV Material
 Visible Material
 IR Material
 Color Material
 Sperical Material

Zinc Selenide (ZnSe)

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 @ 273°K, 7.8 x 10-6 /°K @ 373°K, 8.3 x 10-6 /°K @ 473°K
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