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
