Europe, UK, Asia & RoW: [email protected] +44 (0)1622 859444 | USA & Canada: [email protected] +1 401-583-7846

Knight Optical Custom Optical Components - Page Header - Optics Laboratory

Custom Zinc Selenide

Zinc Selenide Lenses

Stock Available

Bespoke Ordering Available

Contact us now

Find out more about our custom zinc selenide

Call +44 (0)1622 859444 Call +1 401 583 7846
Global leaders in custom optical solutions
Internationally recognised
All optical components 100% QA checked
ISO14001 & ISO9001 certified

Knight Optical is your go-to supplier for top-notch zinc selenide components, tailored to meet your unique specifications. Our product range includes not only ZnSe windows but also ZnSe lenses and prisms.

Whether you’re in need of uncoated or coated optics, we’ve got you covered. Our coatings include broadband antireflective (BBAR) coatings, which significantly enhance the zinc selenide transmission qualities of your custom optical components.

Zinc Selenide Lenses

Speak to our experts about your Custom Zinc Selenide needs today

Call +44 (0)1622 859444 Call +1 401 583 7846

Make a quick enquiry about Custom Zinc Selenide Now

Dive into the forefront of optical solutions. Got questions about an optical product? Reach out now and let our expertise guide you.

    Optical Properties of Zinc Selenide

    Zinc Selenide (ZnSe) is a noteworthy polycrystalline semiconductor that stands out for its excellent transmission properties. Specifically, it offers about 70% transmission between the wavelengths of 1-15µm and readily transmits from 600nm to 21µm.

    Manufactured through chemical vapour deposition (CVD), ZnSe optics come with a range of impressive characteristics:

    • High purity: Ensures minimal impurities in the ZnSe lenses.
    • High refractive index homogeneity: Contributes to the high-quality performance of ZnSe lenses.
    • Chemically inert: This makes ZnSe particularly stable in various environments.
    • High damage threshold: Enables ZnSe optics to withstand intense light or thermal conditions.
    • Insoluble in water: Enhances the material’s resilience in humid or wet conditions.
    • Highly resistant to thermal shock: Further adds to the durability of zinc selenide lens products.
    • Non-hygroscopic: Ensures that ZnSe lenses don’t absorb moisture, thus maintaining their integrity.
    • Low bulk loss: Characterised by a low zinc selenide absorption coefficient and zinc selenide absorption spectrum, resulting in minimal loss from absorption and scattering.

    All these attributes make zinc selenide glass and optics highly sought-after in various applications.

    While we do have a set of typical manufacturing specifications, it’s worth noting that we are continually expanding our capabilities in the realm of ZnSe optics. So, if you don’t see your specific requirements listed, don’t hesitate to get in touch. Our technical sales team is always on hand to guide you through your enquiry and find the perfect zinc selenide lens or other component that meets your needs.

    Transmission range0.6 to 21µm
    Refractive Index2.4028 @ 10.6µm
    Density5.27 g/cm3
    Melting Point1525°C
    HardnessKnoop 120 with 50g indenter
    Operating Temperature< 250°C
    Diameter< 5mm to 100mm +
    Form error (@633nm)< 1 wave
    Centration /parallelism< 3 arc minute
    Scratch/dig< 60/40
    Typical coatingsSingle sided BBAR @ 2-14µm
    Graph to depict the optical properties of Zinc Selenide, uncoated - 1mm thick

    Uncoated, 1mm thick

    Frequently Asked Questions

    Zinc selenide is a crystalline material which exhibits high transmission and low absorbance which makes it a popular choice in laser applications such as high-powered CO2 lasers.  

    ZnSe lenses are optical lenses manufactured from zinc selenide, a polycrystalline material with a transmission waveband that extends from visible through to infrared. This transmission itself secures zinc selenide’s place as an optimal material for CO2 lasers with transmission at both 10.6µm for the CO2 laser, but also at 632.8nm for the accompanying HeNe alignment laser. 

    ZnSe optics are manufactured from zinc selenide, a crystalline material, and are well suited for applications in the infrared region, but unlike some other infrared crystalline materials, such as germanium and silicon, its wavelength range extends into the visible spectrum. The optical material chosen is dependent on the requirements of the specific application they are being used for, all have their own advantages. 

    Yes, zinc selenide glass is different from regular glass in areas such as its optical properties, composition, and the applications in which it is used.  Unlike regular glass, which is typically amorphous and made from varying materials to achieve specific properties, zinc selenide is made by a crystal growth process. 

    The purity of the material can affect zinc selenide’s transmission, and impurities or defects can reduce the transmission as they may absorb or scatter the light. Factors such as temperature and surface quality can also affect the transmission. However, applying a coating can enhance the transmission, especially an anti-reflective (AR) coating. 


    Is your question not here?

    We are ready and waiting to answer any queries you may have about zinc selenide.

    Additional Information

    Hazardous material

    It’s crucial to note that zinc selenide is a hazardous material, and proper safety measures should be in place when handling any ZnSe lenses or other ZnSe components. For detailed information on the safety protocols, you can consult our Zinc Selenide SDS (Safety Data Sheet), which outlines all necessary precautions.

    Typical Applications

    Infrared Lenses for Low Powered CO2 Lasers

    CO2 Lasers

    In the realm of laser applications, laser-grade ZnSe infrared lenses play a pivotal role, particularly as CO2 laser focal lenses. These lenses excel in transmission at the 10.6µm wavelength, while maintaining minimal zinc selenide absorption coefficient. Uniquely, ZnSe is the only infrared material that also transmits at 632.8nm, making it ideal for CO2/HeNe laser pairings.

    For systems where a CO2 and HeNe laser are used together, zinc selenide beam combiners are often the component of choice. Positioned at a 45° angle to the CO2 laser, these beam combiners transmit the CO2 beam at 10.6µm while reflecting the HeNe beam at 632.8nm. This 45° reflection integrates the HeNe beam into the path of the CO2 laser beam, effectively combining the two.

    Additionally, zinc selenide resonator windows are frequently used to separate the gas medium from the resonator optics, thereby ensuring the integrity and performance of the laser system.

    Infrared Lenses for FLIR Thermal Imaging

    FLIR and Thermal imaging

    Zinc selenide optical windows are commonly employed as protective elements in both Forward Looking Infrared (FLIR) and thermal imaging systems. These ZnSe windows are often outfitted with Broadband Antireflective (BBAR) coatings. 

    The purpose of these coatings is to minimise reflection back into the system, thereby maximising the zinc selenide transmission capabilities of the optical component. The BBAR coatings significantly improve the performance by reducing any potential zinc selenide absorption spectrum and ZnSe absorption coefficient issues, ensuring optimal functionality in these critical applications.

    Germanium for Fourier Transform Infrared Spectroscopy (FTIR)

    Fourier Transform Infrared Spectroscopy (FTIR)

    Owing to its broad transmission band, zinc selenide serves as an ideal substrate for Attenuated Total Reflection (ATR) crystals in FTIR spectroscopy. Its extensive transmission capabilities mean that ZnSe is highly effective for this analytical technique, minimising any ZnSe absorption spectrum or zinc selenide absorption coefficient issues that could compromise the quality of spectral data. Thus, when it comes to FTIR spectroscopy, zinc selenide optics, particularly ATR crystals, are often the substrate of choice for professionals in the field.

    Get in touch with us:

    With our in-house state-of-the-art metrology laboratory you can be confident that your optical components will meet your requirements. You can find out more about our testing facilities here.









      Main Form CTA Image

      Operating for over 30 years

      Knight Optical has been operating for over 30 years, with our managing director Colin Overton at the helm. Over this time, we have become a global leader in the production and distribution of scientific optical components and bringing quality into focus for all of our products and services that we provide.

      Our 2022/2023 Catalogue

      Inside Knight Optical’s catalogue you’ll find details of the industries we serve as well as the many other services we can offer. It also showcases hundreds of our most popular products, supported by useful technical information, to help you choose the right part for your application.
      Click below to view our digital catalogue now.

      view our catalogue