Zinc Selenide (ZnSe) is a type of IR (Infrared) material that is a light yellow compound of zinc and selenium. The most popular usage is to make ZnSe lenses, along with Zinc Selenide windows and beam splitters, ZnSe lenses are some of the most used optical components in infrared applications today.
At Shanghai Optics, we design and manufacture standard and custom ZnSe lenses for companies and institutions around the world. Here’s everything you need to know about our ZnSe lenses and their strengths.
What Makes ZnSe Lenses Important?
As an optical material, ZnSe has a number of properties that make it ideal for mid-infrared applications. Perhaps its greatest draw is its ability to transmit both infrared and visible light wavelengths, which no other common IR transmitter shares, which enables inspection and testing after completion of the production compared to other IR materials that block visible lights which makes optical inspection harder than usual.
Other benefits of ZnSe as a lens material include:
- Low absorption at infrared wavelengths: High quality ZnSe material absorbs minimal light when it’s used for infrared wavelengths. This quality helps reduce energy loss and increase accuracy in sensitive instrumentation. Because infrared lenses are most commonly used to focus energy to a small point in laser applications, ZnSe’s low absorption is a great advantage. ZnSe lenses from Shanghai Optics have less than 0.3 percent total absorption when measured using CO2 laser calorimetry.
- Resistance to thermal shock: ZnSe lenses also resist thermal shock better than most IR materials, which prevents damage and keeps the lens functioning properly when it’s used in high-energy laser applications.
- Cost-effective: As ZnSe has become the substrate of choice for infrared optics, buying ZnSe lenses has grown more affordable. Coupled with the material’s significant performance advantages, this factor makes ZnSe the most cost-effective option in many Infrared application cases.
ZnSe lenses come in multiple designs, making them ideal for almost any application that requires transmitting high-power infrared wavelengths. Common ZnSe lens uses include thermal imaging, CO2 laser systems and applications in life sciences.
How ZnSe Lenses Are Produced
ZnSe (Zinc Selenide material) rarely occurs in nature, so for someone to produce ZnSe lenses, it must be man made. Once a ZnSe blank has been made, however, the manufacturing process follows as you might expect for any type of high-performance optical lens. S.O. uses the following steps to produce ZnSe lenses:
- Lens design: Before we can begin manufacturing your lens, we need a design to work from. The type of ZnSe lens design we use will depend on your specifications and the lens’ intended custom IR application.
- Lens formation: Like other types of optical lenses, ZnSe lenses are either molded or cut from a substrate material. Once we’ve formed the rough shape of the lens, we use diamond turning to match to its exact dimensions, curve and roughness specified in the original lens design.
- Lens coating: To ensure minimal absorption in mid-infrared applications, a ZnSe lens must be free of internal and external defects that could disrupt light. Even a thin lens coating has the potential to affect performance. We provide ZnSe (Zinc Selenide) lenses without exterior coatings to promote high performance in CO2 laser focusing applications. However, we can apply anti-reflection and other optical coatings as desired.
- Final testing: Before any Shanghai Optics lens is complete, it undergoes rigorous testing to ensure it matches your specifications. Our staff members use a range of cutting-edge metrology equipment to test lenses for accuracy and performance.
We design and manufacture spherical, cylindrical and meniscus ZnSe lenses in multiple diameters, thicknesses and configurations. 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.
Contact us for manufacturing limit or custom specifications.
- Substrate Material: ZnSe
- Shape: Spherical Plano-Concave, P-Convex, Concave-Convex or Aspheric
- Surface Figure: λ/20 before coating at 10.6μm
- Surface Quality: 40-20 per MIL-PRF-13830B
- Dimensional Tolerance: + 0.00mm, – 0.25mm
- Thickness Tolerance: +/- 0.25mm
- Chamfer: 0.35mm at 45° typical
- Concentricity: < 0.05mm
- Focal Length Tolerance: +/- 2%
- Antireflection Coating: Ravg < 0.6% per surface at 3-5μm
Ravg < 0.75% per surface at 8-12μm
Ravg < 0.5% per surface at 10.6μm
- Clear Aperture: Exceeds central 85% of dimension
- Absorption: <0.3% total absorption as measured by CO2 laser calorimetry
- Design Wavelength: 10.6μm
Custom ZnSe Lenses From S.O.
With more than 55 years of experience, Shanghai Optics has the expertise and technical capability to produce high-quality customized ZnSe lenses at a competitive price. Request a quote online today to find out how working with S.O. can benefit your business.