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  • ZnSe Focusing Lenses for CO2 Lasers (Custom)
  • ZnSe Focusing Lenses for CO2 Lasers (Custom)

ZnSe Focusing Lenses for CO2 Lasers (Custom)

  • Two types of lenses available: Plano-convex and Meniscus lenses
  • High-Quality CVD ZnSe grew in America, ensuring efficient power output and thermal resistance
  • AR coating with an excellent transmittance of T≥99.5%@10.6mm
  • Maximum diameter 200mm
  • Off-the-shelf stocked modules and custom design service available
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Materials CVD ZnSe crystals Size Tolerance +0.0/-0.1mm
Central Thickness Tolerance +/-0.1mm Surface Quality 40/20 S/D
Frings (N) <3 Irregularity(delta N) <1
Centration <3’ Tolerance of Focal Length +/-1%
Aperture >90% Chamfer 0.1-0.3mmx45degree
Coating AR/AR@10.6μm (T>99.5%@10.6μm)

Basic Properties:

Transmission Range 0.6 to 21.0μm Refractive Index 2.4028 at 10.6μm
Reflection Loss 29.1% at 10.6μm (2 surfaces) Absorption Coefficient 0.0005 cm-1 at 10.6μm
Reststrahlen Peak 45.7μm dn/dT +61 x 10-6 /°C at 10.6μm at 298K
dn/dμ = 0 5.5μm Density 5.27 g/cc
Melting Point 1525°C (see notes below) Thermal Conductivity 18 W m-1 K-1 at 298K
Thermal Expansion 7.1 x 10-6 /°C at 273K Hardness Knoop 120 with 50g indenter
Specific Heat Capacity 339 J Kg-1 K-1 Dielectric Constant n/a
Youngs Modulus (E) 67.2 GPa Shear Modulus (G) n/a
Bulk Modulus (K) 40 GPa Elastic Coefficients Not Available
Apparent Elastic Limit 55.1 MPa (8000 psi) Apparent Elastic Limit 55.1 MPa (8000 psi)
Poisson Ratio 0.28 Solubility 0.001g/100g water
Molecular Weight 144.33 Class/Structure HIP polycrystalline cubic, ZnS, F43m

The Focusing Lens is an indispensable part of CO2 laser systems for laser processing (cutting, punching, welding, graving, etc) and other kinds of applications. There are conventionally two types of laser focusing lenses, plano-convex and meniscus lenses, which are both available in Shalom EO. Generally, Plano-convex ZnSe Lenses are the more conventional option, but for applications involving greater beam sizes and power densities, Meniscus ZnSe Lenses are more ideal in terms of lower spherical aberrations. Zinc Selenide (ZnSe) is a popular material to be manufactured into focusing lenses for CO2 lasers. ZnSe is advantageous due to having the lowest absorption compared to other common CO2 laser transmitting materials, therefore particularly suitable for high-power applications. However, being relatively soft, ZnSe might be more sensitive to scratches, for applications in dirty or high-splatter environments, Shalom offers GaAs focusing lenses for CO2 lasers, GaAs has a relatively high hardness and a greater thermal conductivity which helps to repel debris particles and transmit heat away from embedded particles.

Hangzhou Shalom EO offers Plano-convex and Meniscus Zinc Selenide (ZnSe) Focusing Lens for CO2 laser systems and versatile applications. For off-the-shelf versions, the specifications are: Diameters 12.0-38.1mm, Central Thicknesses 2.6-7.87mm, Focal Length 38.1-190.5mm with 10.6μm AR Coatings. For custom versions, the maximum diameter is 200mm, suggesting the potentiality to handling higher power levels.

Shalom EO chooses CVD (chemically vapor deposited) ZnSe which features extremely low bulk losses due to absorption and scatter, high resistance to thermal shock, and stability in virtually all environments. Due to the relatively high refractive index of ZnSe, AR coating is critical to obtaining high transmission. Additionally, Shalom EO incorporates the minimum-damage polishing technology during the coating process, and our  AR coating ensures a high damaging threshold, high durability, and wiping resistance, with an excellent transmittance of T≥99.5%@10.6mm. Our experienced tech support is capable and willing to provide consultancy to deliver you the appropriate lens modules, which guarantee optimized interest for your laser systems, and economized costs. If you have any other specific requirements, we are also able to offer design services for custom focusing lenses.

Application Notes:

While selecting the right focusing lens for your laser systems, you need to take several important considerations:

  • How precisely do you need the graphics to be
  • How much is the output of your laser device (laser beam wattage).
  • Which materials are to be processed and what processing purpose (cutting or engraving).
  • The thickness of the material (the penetration depth of the materials)