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Calcium Fluoride (CaF2) Windows

  • Maximum diameter 200mm
  • Transmitting range 0.18μm to 8.0μm
  • High transmission rate in the UV, VIS ,and IR region
  • High damage threshold and low chromatic aberration
  • Applications: Spectroscope, thermal imaging, fluorescence imaging, excimer laser, etc.
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Materials IR Grade Calcium Fluoride Crystals Aperture >90%
Dimension Tolerance +0.0/-0.2mm Thickness Tolerance +/-0.1mm
Surface Quality 60/40 S/D Parallelism 1 arc minute
Chamfer 0.3-0.5mmx45degree Coating Optional protective coating

Physical and Optical Properties:

Transmission Range 0.13 to 10 μm Refractive Index 1.39908 at 5 μm (1) (2)
Reflection Loss 5.4% at 5 μm Absorption Coefficient 7.8 x 10-4  cm-1 @ 2.7 μm
Reststrahlen Peak 35 μm dn/dT -10.6 x 10-6 /°C (3)
dn/dμ = 0 1.7 μm Density 3.18 g/cc
Melting Point 1360°C Thermal Conductivity 9.71 W m-1 K-1 (4)
Thermal Expansion 18.85 x 10-6 /°C (5)(6) Hardness Knoop 158.3 (100) with 500g indenter
Specific Heat Capacity 854 J Kg-1 K-1 Dielectric Constant 6.76 at 1MHz (7)
Youngs Modulus (E) 75.8 GPa (7) Shear Modulus (G) 33.77 GPa (7)
Bulk Modulus (K) 82.71 GPa (7) Elastic Coefficients C11 = 164 C12 = 53 C44 = 33.7 (7)
Apparent Elastic Limit 36.54 MPa Poisson Ratio 0.26
Solubility 0.0017g/100g water at 20°C Molecular Weight 78.08
Class/Structure Cubic (111) cleavage


Calcium Fluoride (CaF2 ) Windows, featuring high average transmission in the deep UV to near IR wavelength range (180 nm-8 µm), and low absorption coefficients, are competent for applications in the UV, Visual, and IR regions . CaF2 has a low chromatic aberration relative to other IR materials, therefore the material exhibits great imaging functionalities. Calcium Fluoride also has the advantages of high damage threshold, chemical resistance.Its Group Velocity Dispersion (GVD) is the lowest among the IR transmitters, therefore CaF2 is also recommendable for Femtosecond IR systems.

Hangzhou Shalom EO offers Calcium Fluoride Windows with protective coatings and assembled windows with metal holders. These products are requisite for spectroscopes or fluorescence imaging/ thermal imaging, the uncoated window substrates are excellent for excimer laser. 

Transmission curve of the CaF2 windows of different thickenss

IR Inspection Windows Assemblies

IR Inspection Windows Assemblies

  • Anodized Aluminium holder
  • Dust tight design IP67
  • Variety IR materials: Germanium, CaF2 and BaF2
  • Easy installation, no screw needed