Zink Selenide (ZnSe)

 znse-materials.jpgZnSe is a preferred material for lenses, windows, output couplers and beam expanders for its low absorptivity at infrared wavelengths and its visible transmission. For high-power applications, it's critical that the material bulk absorption and internal defect structure be carefully controlled, that minimum-damage polishing technology be employed, and the highest quality optical thin-film coatings are used. The material absorption is verified by CO2 laser vacuum calorimetry. Our quality assurance department provides testing and specific optics certification on request. ZnSe optics are routinely polished from 5 to 300 mm in diameter. Sizes in 300 mm diameter and 25 mm thick are manufactured to customer requirements. ZnSe is non-hygroscopic and chemically stable, unless treated with strong acids. It's safe to use in most industrial, field, and laboratory environments.



znse_transmission.jpg

ZnSe Transmission Charts Thermo-Optic Coefficient @ Various Wavelengths dn/dT (10-5°C-1)

Material Properties

Optical Properties  
Bulk Absorption Coefficient @ 10.6µm <= 0.0005 cm-1
Temperature Change of Refractive Index @ 10.6µm 61 x 10-6/°C
Refractive Index Inhomogeneity @ 632.8 nm < 3 x 10-6
   
Thermal Properties  
Thermal Conductivity @ 20° C 0.18 W/cm/°C
Specific Heat 0.356 J/g/°C
Linear Expansion Coefficient @ 20° C 7.57 x 10-6/°C
   
Mechanical Properties  
Young’s Modulus 67.2 GPa (9.75 x 106 psi)
Rupture Modulus 55.1 MPa (8,000 psi)
Knoop Hardness 105-120 kg/mm2
Density 5.27 g/cm3
Poisson’s Ratio 0.28
   
Wavelength
(µm)
Index Wavelength
(µm)
Index Wavelength
(µm)
Index Wavelength
(µm)
Index
0.54 2.6754 1.8 2.4496 7.4 2.4201 13.0 2.3850
0.58 2.6312 2.2 2.4437 7.8 2.4183 13.4 2.3816
0.62 2.5994 2.6 2.4401 8.2 2.4163 13.8 2.3781
0.66 2.5755 3.0 2.4376 8.6 2.4143 14.2 2.3744
0.70 2.5568 3.4 2.4356 9.0 2.4122 14.6 2.3705
0.74 2.5418 3.8 2.4339 9.4 2.4100 15.0 2.3665
0.78 2.5295 4.2 2.4324 9.8 2.4077 15.4 2.3623
0.82 2.5193 4.6 2.4309 10.2 2.4053 15.8 2.3579
0.86 2.5107 5.0 2.4295 10.6 2.4028 16.2 2.3534
0.90 2.5034 5.4 2.4281 11.0 2.4001 16.6 2.3487
0.94 2.4971 5.8 2.4266 11.4 2.3974 17.0 2.3448
0.98 2.4916 6.2 2.4251 11.8 2.3945 17.4 2.3387
1.0 2.4892 6.6 2.4235 12.2 2.3915 17.8 2.3333
1.4 2.4609 7.0 2.4218 12.6 2.3883 18.2 2.3278


Wavelength
Temp °C 0.632µm 1.5µm 3.39µm 10.6µm
-180 7.6 5.4 5.0 4.9
-160 8.2 5.7 5.2 5.1
-140 8.7 6.0 5.4 5.4
-120 9.1 6.3 5.6 5.5
-100 9.4 6.5 5.8 5.7
-80 9.7 6.6 5.9 5.8
-60 10.0 6.7 6.0 5.9
-40 10.2 6.8 6.1 6.0
-20 10.3 6.9 6.1 6.0
0 10.5 7.0 6.2 6.1
20 10.6 7.0 6.2 6.1
40 10.7 7.0 6.2 6.1
60 10.8 7.1 6.3 6.1
80 10.9 7.1 6.3 6.2
100 11.0 7.2 6.3 6.2
120 11.1 7.2 6.4 6.3
140 11.3 7.3 6.4 6.3
160 11.5 7.4 6.5 6.4
180 11.8 7.6 6.6 6.6
200 12.1 7.8 6.7 6.7
oa 0.1 0.1 0.1 0.1
a Standard deviation from a third degree polynomial fit
A.Feldman et al, “Optical Materials Characterization Final Technical Report Feb. 1, 1978 - Sept. 30, 1978,” National Bureau of Standards Technical Note 933, Pages 53 and 54.

Prism-Grade Zinc Selenide

znse_prism.jpgZinc Selenide (ZnSe) Prism Grade

II-VI Infrared has the capability to grow prism grade ZnSe up to 2.50” thick. Prism grade ZnSe exhibits minimal refractive index variations within the material on planes perpendicular to the growth direction as well as in other directions. Index variations will test to less than 3 ppm at 0.6328 microns regardless of orientation. Prism grade ZnSe is commonly used in thermal imaging systems. Call our technical sales staff to discuss your specific requirements for material greater than 2.50” thick.


  • Refractive index variation less than 3 ppm @0.6328µm in all directions
  • Consistent optical performance independent of orientation
  • Thickness to 2.50"