Crystals Materials
Zinc Sulfide (ZnS) for thermal imaging applications
  • Surface Quality: 10/5 Scratch/Dig MIL-O-1380A
  • Parallelism: < 10″
  • Perpendicularity: < 5'
  • Clear Aperture: > 90%
  • Surface Flatness: < λ/10 @ 632.8 nm
  • Coating: AR/HR/PR coating upon customer's request
  • Quality Warranty Period: One year
  • Zinc Sulfide (ZnS) Multispectral Windows are manufactured from a water-free, multi-spectral grade of zinc sulfide that has low absorption and scatter properties over its broad transmission range of 0.4 - 12μm. Zinc Sulfide Multispectral is a chemical vapor deposited material which is commonly used in thermal imaging. With its excellent transmission properties in the visible and infrared, Zinc Sulfide Multispectral is the material of choice for systems that have both visible and mid-wave or long-wave infrared sensors.

    Specifications of KYW Crystal
    Material Zinc Sulfide (ZnS)
    Diameter 3mm ~ 300mm
    Thickness >0.1mm
    Dimension Tolerance +0/-0.02mm
    Angle Tolerance ±15 arcsec
    Surface Accuracy λ/10 @ 633nm
    Surface Quality S/D 10–5
    Pyramid Tolerance <5 arcmin
    Bevel <0.25mm X 45°
    Coating Available upon request
    Physical and optical properties
    Crystal Structure Cubic
    Density 5.27 g/cm³
    Crystal Size <100 μm
    Impurities None > 0.05 mm
    Resistivity > 10^12 ohm-cm
    Dielectric Constant Consult Technical Personnel
    Absorption Coefficient @10.6μm <0.0005 cm^-1
    Thermal Optical Coefficient (dn/dT) @10.6μm 6.1 × 10^-5 ℃
    Refractive Index Uniformity @0.6328μm <3 × 10^-6
    Thermal Conductivity @20°C 0.18 W/cm/℃
    Specific Heat 0.356 J/g/℃
    Linear Expansion Coefficient @20°C 7.57 × 10^-6/℃
    Young's Modulus 67.2 GPa (9.75 × 10^6 psi)
    Fracture Modulus 55.1 MPa (8,000 psi)
    Knoop Hardness 105-120 kg/mm²
    Poisson's Ratio 0.28
    Fracture Toughness 0.5 × 10^6 N/m^3/2

    Stock specification list

    If need other specifications and quantities products, please contact us(
    Part Number Face size Thickness Surface Quality Coating
    WIN-080-020-ZnS Dia 8.00 mm 2.00 mm 40/20 UnCoated
    WIN-127-020-ZnS Dia 12.70 mm 2.00 mm 40/20 UnCoated


  • Anti-reflection coatings are available at your specified wavelength.
  • Be sure to wear laser safety goggles when checking optical path and adjusting optical axis.
  • To inquiry or order a finished KYW laser rod, please specify the specification listed above, for common application, we only need to know the main specification: Nd-dopant concentration, sizes, and coating. For special request, please specify specification in details for evaluation and fabrication.
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