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Optical Material

Zinc Selenide (ZnSe)

Zinc Selenide (ZnSe) is a polycrystalline infrared material with excellent transmission from the visible through the far infrared. It is the standard material for CO₂ laser optics and is widely used in thermal imaging and IR spectroscopy systems.

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Key Optical Properties

Property Value
Transmission Range 0.6 μm – 18 μm
Refractive Index 2.4028 @ 10.6μm
Thermal Expansion 7.1 × 10⁻⁶ /K (20-300°C)
Density 5.27 g/cm³
Knoop Hardness 120 HK

Advantages

  • Excellent IR transmission (0.6μm to 18μm)
  • Good thermal conductivity for CO₂ lasers
  • Standard material for 10.6μm CO₂ optics
  • Visible and IR transmission — useful for alignment
  • Low absorption at CO₂ wavelength

Limitations

  • Soft material — easily scratched
  • Toxic material — special handling required
  • High refractive index requires AR coating
  • More expensive than Ge or Si
  • Yellow/orange color (visible light absorption)

Typical Applications

CO₂ laser windows and lenses

Thermal imaging systems

FTIR spectroscopy

Medical laser systems

IR optical sensors

Common Coating Options

Standard coating types available for this material. Custom coating designs available on request.

AR coatings for 10.6μm
Broadband IR AR (8-12μm)
Dual-band AR (visible + CO₂)
Diamond-Like Carbon (DLC)
Partial reflection for output couplers

Products Using ZnSe (Zinc Selenide)

Browse our catalog of precision optical components available in Zinc Selenide (ZnSe)

Windows

ZnSe Circular/Square Windows

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Filters

IR Transmission Visible Absorption Filters

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Polarizers

IR Polarizers

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