IR Windows Calcium fluoride (CaF2) Windows
Calcium fluoride (CaF2) is an insoluble ionic compound of calcium and fluorine. It is commonly used as a window material for both infrared and ultraviolet wavelengths, since it is transparent in these regions (about 0.15 μm to 9 μm) and exhibits extremely weak birefringence. Furthermore the material is fairly inert chemically so that these windows are not attacked. Nevertheless, at wavelengths as low as 157 nm, which are interesting to semiconductor manufacturers, the birefringence of calcium fluoride exceeds tolerable limits. This problem with birefringence can be mitigated through optimised growth process. It is particularly important as an ultraviolet optical material for integrated circuit lithography.
CaF2 material advantage
1. Low absorption coefficient
2. High damage threshold,
3. Low Dispersion (with an Abbe Number of 95)
4. Low fluorescence
5. Excellent water, chemical, and heat resistance
We provide artificially-crystallized calcium fluoride components available in IR grade and UV Grade. The cost of UV grade is much expensive than IR grade.
WTS make customized CaF2 window, CaF2 Lens.
Note:Fluorides are toxic to humans, however CaF2 is considered relatively harmless due to its extreme insolubility
CaF2 Windows SPECIFICATION:
|
Material:
|
CaF2
|
|
Dimension Tolerance:
|
+0.0, -0.1mm
|
|
Thickness Tolerance:
|
± 0.1mm
|
|
Surface quality:
|
80/50
|
|
Clear Aperture:
|
>85%
|
|
Flatness:
|
λ per 25mm
|
|
Parallelism:
|
3'
|
|
Bevel:
|
<0.25mm X 45°
|
|
Coating:
|
Upon requirement
|
|
|
CaF2 Main Properties and Performance
|
|
|
Transmission range (μm)
|
0.13~9.0
|
|
Transmittance
|
＞90% (0.3~7μm, 3mm)
|
|
Refractivity(5μm)
|
1.39908
|
|
Expansion Coefficient (℃-1)
|
18.85×10-6
|
|
Knoop hardness (kg/mm2)
|
158.3（100）
|
|
Elastic Coefficients
|
C11=164; C12=53; C44=33.7
|
|
Young’s modulus (GPa)
|
75.79
|
|
Poisson’s ratio
|
0.28
|
|
Solubility (g/100gH2O·20℃)
|
0.0017
|
|
Cleavage plane
|
-111
|
|
Density(g/cm3)
|
3.18
|
|
Melting Point(℃)
|
1360
|
|
Typical Sizes:
|
|
|
Round Shape
|
Φ5.0; Φ10.0 ; Φ12.7; Φ15.0; Φ20.0;
|
|
Diameter(mm):
|
Φ25.4; Φ30.0; Φ38.1; Φ50.8; Φ76.2
|
|
Square Shape:
|
5.0x5.0 ; 10.0x10.0 ; 15.0x15.0 ;
|
|
WxH(mm)
|
20.0x20.0; 25.0x25.0; 50.0x50.0
|
|
Thickness(mm):
|
0.5; 1.0; 1.5; 2.0; 3.0;
|
|
|
4.0; 5.0; 6.0; 8.0; 10.0
|
