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Zinc Sulfide (ZnS) Windows

  • Maximum diameter 250mm
  • Grown by CVD method
  • Transmitting range 0.4μm to 14.0μm for multi-spectrum grade ZnS
  • Ideal for aircraft frames
Curves of ZnS Windows.pdf All Inquire Us  


Materials CVD ZnS crystals, IR grade or Cleartran grade Diameter Range ~ 250mm
Aperture >90% Dimension Tolerance +0.0/-0.2mm
Thickness Tolerance +/-0.1mm Surface Quality 60/40 S/D
Parallelism 1 arc minute Chamfer 0.3-0.5mmx45degree
Coating AR/AR coating@7-14μm


Physical and Optical Properties:

Transmission Range 0.37 to 13.5 μm Refractive Index 2.20084 at 10 μm
Reflection Loss 24.7% at 10 μm (2 surfaces) Absorption Coefficient 0.0006 cm-1 at 3.8 μm
Reststrahlen Peak 30.5 μm dn/dT +38.7 x 10-6  /°C at 3.39 μm
dn/dμ = 0 n/a Density 4.09 g/cc
Melting Point 1827°C (See notes below) Thermal Conductivity 27.2 W m-1 K-1 at 298K
Thermal Expansion 6.5 x 10-6 /°C at 273K Hardness Knoop 160 with 50g indenter
Specific Heat Capacity 515 J Kg-1 K-1 Dielectric Constant 88
Youngs Modulus (E) 74.5 GPa Shear Modulus (G) n/a
Bulk Modulus (K) n/a Elastic Coefficients Not Avalailable
Apparent Elastic Limit 68.9 MPa (10,000 psi) Poisson Ratio 0.28
Solubility 65 x 10-6 g/100g water Molecular Weight 97.43
Class/Structure HIP poly-crystalline cubic, ZnS, F42m

ZnS or Zinc Sulphide crystals grown by chemical vapor deposition (or CVD) exhibits exceptional fracture strength and hardness leading to its frequent choice for military applications or other harsh environments. This material is often used in the LWIR 7 to 14 microns region of thermal imaging. Its high resistance to rain erosion and high-speed dust and particulate abrasion makes it particularly suitable for exterior IR windows on aircraft frames.

Hangzhou Shalom EO provides the ZnS windows of IR grade and Cleartran or multi-spectrum grade materials, the AR/AR coating is made to increase the transmission of the windows.

1.Transmission curve of the ZnS windows with AR/AR Coating

2.Transmission at visible wavelength range