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ZnS Lenses

Features:

  • Good transmission from 0.4 to 14μm for multi-spectrum grade ZnS
  • Good choice for aircraft applications


Curves All Inquire Us  

pecifications:

Materials CVD or Cleartran grade ZnS crystals Diameter Range ~200mm
Diameter Tolerance +0.0/-0.2mm Thickness Tolerance +/-0.2mm
Surface Quality 60/40 S/D Frings (N) 3
Irregularity (delta N) 1 Centration 3'
Chamfer 0.1-0.3mmx45 degree Coatings AR/AR@7-14micro
 

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 polycrystalline cubic, ZnS, F42m

ZnS or Zinc Sulphide crystals grown by chemical vapor desposition (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 14μm region of thermal imaging, and the multi-spectrum grade ZnS has a good transmission in 0.4 to 14μm, which covers visible to LWIR wavelength range . 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 lenses of IR grade and Cleartran or multi-spectrum grade materials, the AR/AR coating is made to increase the transmission of the lenses.

Curves:

1.Transmission of AR coated CVD ZnS substrates at 7-14 micro

2.Transmission at visible wavelength range