Zinc sulphide

Zinc sulfide (ZnS) is a significant optical material widely recognized for its versatile properties and extensive range of applications. Primarily transparent to a broad spectrum of wavelengths, especially within the visible and infrared regions.

In optics, ZnS finds application in various critical components and devices, including lenses, windows, prisms. Its significance is particularly pronounced in infrared optics, where it plays a pivotal role in thermal imaging systems, infrared cameras, night vision devices, and laser systems. The modified ZnS multispectral variant, renowned for its superior infrared transmission properties, is often preferred for these applications.

Manufacturing processes for ZnS encompass chemical vapor deposition (CVD) and physical vapor deposition (PVD), ensuring the production of uniform, high-quality ZnS films and coatings with precise control over thickness and composition.

However, it is worth noting that while ZnS offers remarkable optical properties, its relatively soft nature renders it susceptible to scratching and damage. Consequently, meticulous handling and protective measures are imperative to safeguard the integrity of ZnS optical components.

In summary, zinc sulphide (ZnS) is a versatile and indispensable optical material, revered for its transparency across various wavelengths and compatibility with an array of manufacturing techniques. Its widespread application in optics, especially in the infrared spectrum, underscores its paramount importance in modern optical systems and devices.

Optical Grade Zinc Sulfide (ZnS) is a widely used infrared material with the following technical properties:

Transmission Range: 0.37 to 13.5 μm

Refractive Index: 2.20084 at 10 μm

Reflection Loss: 24.7% at 10μm (2 surfaces)

Absorption Coefficient:

0.2 cm-1 @ 10.6 μm

0.006 cm-1 @ 9.27 μm

0.0006 cm-1 @ 3.8 μm

0.0001 cm-1 @ 2.7 μm

0.0006 cm-1 @ 1.3 μm

Reststrahlen Peak: 30.5 μm

dn/dT: +38.7 x 10-6 /°C at 3.39 μm

Density: 4.09 g/cc

Melting Point: 1827°C

Thermal Conductivity: 27.2 W m-1 K-1 @ 298 K

Thermal Expansion: 6.5 x 10-6/°C @ 273 K

Hardness Knoop: 240 with 50g indenter

Specific Heat Capacity: 515 J Kg-1 K-1

Dielectric Constant: 88

Young’s Modulus (E): 74.5 GPa

Elastic Coefficients: C11 = 89.2, C12 = 40.0, C44 = 25.4

Apparent Elastic Limit: 26.9 MPa (3900psi)

Poisson Ratio: 0.28

Solubility: 65 x 10-6 g/100g water

Molecular Weight: 97.43

Class/Structure: HIP polycrystalline cubic, ZnS, F42m

Please note that these values are typical and may vary based on the grade and manufacturing process of the material