A ZnSe lens is a precision optic commonly used in thermal imaging, high power CO2 laser systems and in the life sciences. At Shanghai Optics we custom manufacture high quality Zinc Selenide lenses to a variety of specifications and in a number of sizes.
Zinc Selenide ZnSe is a transparent, yellowish polycrystalline substance which transmits in the range range 0.5-21µm. It is ideal for mid-infrared applications, but can also transmit some visible light. This means optics incorporating ZnSe lenses lend themselves to visual inspection when IR light is turned off.
The absorption coefficient of Zinc Selenide is 0.0005 cm-1 at 10.6 μm. When used at infrared wavelengths, Shanghai Optics ZnSe lenses have less than 0.3 percent total absorption, as measured using CO2 laser calorimetry. This ultra-low absorption means ZnSe lenses can reduce energy loss and increase accuracy in sensitive instrumentation: a crucial advantage for applications in laser optics where energy is focused on a very small point.
Zinc Selenide has a melting point of 1525°C and a thermal conductivity is 18 W m-1 K-1 at 298K. The thermal expansion coefficient is 7.1 x 10-6 /°C at 273K. Zinc Selenide lenses exhibit a high resistance to thermal shock and can be used in thermally demanding applications.
The reflectivity of Zinc Selenide is typically 29.1% at 10.6 μm (2 surfaces), and our ZnSe lenses can be AR coated for minimal energy loss. Since this is a soft material and can be easily scratched, we recommend you use especial care when handling your ZnSe lenses.
The highest quality ZnSe blanks are those which have been chemically vapor deposited in production, and these are the blanks we use at Shanghai Optics to craft our precision lenses. After a blank has been roughly cut to the desired size and shape, diamond turning is used to match the exact curve, roughness, and dimension specified in the design. The surface of the lens is polished to high standards. For high performance in CO2 laser focusing applications, the lenses are supplied with no coating. However, anti-reflection or other optical coatings can be applied as desired.
Lenses produced at Shanghai Optics factory are rigorously tested to ensure it fully meets your specifications as well as all applicable standards. State of the art metrology equipment is used to test for accuracy and performance.
Spherical, cylindrical, and meniscus lenses are available in several diameters, thicknesses, focal length and configurations. Aspherical, plano-concave, concave-convex , and plano convex lenses are other options. If you aren’t sure which type of ZnSe lens would work best for your application, we can also provide custom ZnSe lens design consulting. Our 55 years of experience ensures that we have both the know how and technical capability to produce the highest quality ZnSe lenses available anywhere, at a competitive price.
Lenses are carefully tested before leaving our factory to ensure it meets all specifications. Please contact us to discuss a custom order, to inquire about our manufacturing limit or custom specifications.