Zinc Selenide (ZnSe) 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. 

ZnSe is a relatively soft material that scratches easily and it is not recommended in harsh environments because its Knoop Hardness is only 120.
ZnSe is non-hygroscopic and chemically stable, unless treated with strong acids. It’s safe to use in most industrial, field, and laboratory environments. Since it is a toxic material, processing and handling are subject to strict procedures.
Zinc Selenide(ZnSe)optics are ideal for a wide variety of infrared applications including thermal imaging, FLIR, and medical systems. This chemically vapor desposited material is widely used in high power CO2 laser systems because of its low absorption coefficient and high resistance to thermal shock. 
LASERTEC manufactures ZnSe products to exacting standards. By employing the minimum-damage polishing technology and the highest quality optical thin-film coatings, LASERTEC carefully control ZnSe bulk absorption and internal defect structure for high-power applications.  

Typical Specification 

Clear Aperture                                      90%
Dimensional Tolerance                     +0.0/-0.1mm
Thickness Tolerance                          ±0.1mm
Center Thickness Tol.                        ±0.2mm
Surface Quality                                    10/5
Centering                                             3-5 arcminutes
Surface Accuracy                                1/10λ@10.6μm
Parallelism                                           <1 acrminute