ZnS Windows An Optical Window is an optically flat. These regular windows are applied to isolate different physical environments while allowing light pass. When selecting windows,please consider materials, transmission, scattering, parallelism and resistance to certain environment. It can be widely used on laser technology, IR detector and imaging technology etc.   Worldhawk offers standard and high precision optical glass windows in round ,rectangular, wedge windows and custom shape and size with different optical glasses,Fused Silica, Sapphire, ZnSe, Zns and IR crystal. The high precision parallelism of 10 arc seconds, surface quality of 10/5 and flatness of λ/20. Single layer or multi-layer anti-reflection coatings are available. Windows General Specifications Diameter  0.2-300mm Diameter tolerance  +/-0.1mm or +/-0.02mm Thickness  0.10-100mm Thickness tolerance  ± 0.1mm or +/-0.02mm Surface quality (scratch & dig)  60/40, 40/20 or better Surface accuracy  λ/10, λ/2, λ Clear Aperture  >85%, >90% Parallelism  +/-3' ,+/-30'' Bevel  0.1~0.3mm×45 degree coating  AR, BBAR or upon customer request( UV, VIS, IR) Materials Characteristic   B270 CaF2 Ge MgF2 N-BK7 Sapphire Si UV Fused Silica ZnSe  ZnS Refractive index (nd) 1.523 1.434 4.003 1.413 1.517 1.768 3.422 1.458 2.403 2.631 Coefficient of dispersion (Vd) 58.5 95.1 N/A 106.2 64.2 72.2 N/A 67.7 N/A N/A Density(g/cm3) 2.55 3.18 5.33 3.18 2.46 3.97 2.33 2.20 5.27 5.27 TCE(μm/m℃) 8.2 18.85 6.1 13.7 7.1 5.3 2.55 0.55 7.1 7.6 Soften Temperature(℃) 533 800 936 1255 557 2000 1500 1000 250 1525 Knoop hardness (kg/mm2) 542 158.3 780 415 610 2200 1150 500 120 120