Zinc Selenide
Zinc selenide (CVD zinc selenide®) is the preferred material for optical components in high energy density CO2 lasers due to its extremely low absorption at 10.6 µm. Its high refractive index homogeneity and excellent optical quality allow it to be used in high-resolution FLIR thermal imaging cameras as well as in laboratory applications such as thermography and spectroscopy.
Resistant materials for VIS and IR applications
Vickers Hardness
112
[kg mm-2]
to operate in harsh enviroments
Chemical purity
99.9996
%
more homogeneous crystal structure
Transmission
0.5 – 22
µm
multispectral in VIS and IR
Its homogeneity and uniformity of refractive index provide excellent optical properties for use as protective windows or optical elements in high-resolution, advanced (FLIR) thermal imaging devices. This material is also used for small windows and lenses in medical and industrial applications such as thermometry and spectroscopy. Zinc selenide (CVD zinc selenide®) is chemically inert, non-hygroscopic, highly pure, theoretically dense and easy to process. It has extremely low absorption and scattering losses, is resistant to high temperatures and is stable in almost all environments.
Special diameters, rectangles, CNC-profiled blanks, generated lens blanks, prisms and near-net-shape domes can be manufactured according to your specifications.
Properties of our zinc selenide (CVD Zinc Selenide®)
| Zinc selenide |
|---|
| Optical properties | |
|---|---|
| 10 % transmission limit (t = 6mm) | 0.5 µm – 22 µm |
| Refractive index inhomogeneity (∆n/n) | < 3 ppm @ 633 nm |
| Thermo-optical coefficient dn/dT (298-358 K) K-1 @ 0.6328 µm K-1 @ 1.15 µm K-1 @ 3.39 µm K-1 @ 10.6 µm | 1.7 x 10-4 7.0 x 10-5 6.2 x 10-5 6.1 x 10-5 |
| Absorption coefficient cm-1 @ 1 .3 µm cm-1 @ 2.7 µm cm-1 @ 3.8 µm cm-1 @ 9.27 µm cm-1 @ 10.6 µm | 5.0 x 10-3 7.0 x 10-4 4.0 x 10-4 4.0 x 10-4 5.0 x 10-4 |
| Thermal properties | |
|---|---|
| Coefficient of thermal expansion [K-1] @ 273 K [K-1] @ 373 K [K-1] @ 473 K | 7.1 x 10-6 7.8 x 10-6 8.3 x 10-6 |
| Thermal conductivity [JK-1m-1s-1] @ 298 K | 18.0 |
| Heat capacity [Jg-1K-1] @ 298K | 0.339 |
| Pulse laser damage | |
|---|---|
| @ 10.6 µm, pulse width 15 µs, 1 pulse |
| Angle of incidence | Fluence [Jcm-2] | Plasma on the surface | Surface damage |
| Normal | 20 | no | No damage |
| Normal | 25 | Yes | Failure |
| Brewster angle | 15 | no | No damage |
| Brewster angle | 20 | no | Damage to the rear |
| Mechanical properties | |
|---|---|
| Knoop hardness: 50 g load [kg mm-2] Vickers hardness: 1 kg load [kg mm-2] | 110 112 |
| Flexural strength (modulus of rupture) 4pt. Load [psi] 4pt. Load [MPa] | 8 x 103 55 |
| Fracture toughness (critical stress intensity factor, KIC-values) [MPa √m, Vickers, 100 g] | 0.5 |
| Modulus of elasticity [psi] [GPa] | 9.75 x 106 67.2 |
| Poisson’s ratio | 0.28 |
| Physical properties | |
|---|---|
| Crystal structure | cubic |
| Grain size [µm] | 50 – 70 |
| Density [g cm-3] @ 298 K | 5.27 |
| Specific resistance [Ω cm] | ~1012 |
| Chemical purity [%] | 99.9996 |
| Refractive indices [@ 20 ºC] | |
|---|---|
| Wavelength [µm] | n |
| 0.54 | 2.6754 |
| 0.62 | 2.5994 |
| 1.00 | 2.4892 |
| 3.00 | 2.24367 |
| 5.00 | 2.4295 |
| 7.00 | 2.4281 |
| 9.00 | 2.4122 |
| 11.00 | 2.4001 |
| 13.00 | 2.3850 |
| 15.00 | 2.3665 |
| 17.00 | 2.3438 |
