Fluorides are usually toxic to humans, however CaF2 is considered relatively harmless due to its extreme insolubility. The material 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. 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 Windows Specifications:
Dimension Tolerance:
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+0.0/-0.2mm
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Thickness Tolerance:
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±0.2mm（General),±0.05(High Precision)
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Surface Quality:
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80/50（General),40/20(High Precision)
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Clear Aperture:
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＞90%
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Flatness:
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λ/2@633nm（General),λ/10@633nm Precision)
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Parallelism:
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<3 arc min.(General). <3 arc sec.(High Precision)
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AR Coated:
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Uncoated, AR, HR, PR, etc.
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Typical Sizes:
Round Shape:Diameter(mm):
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Φ5.0；Φ10.0 ；Φ12.7；Φ15.0；Φ20.0；
Φ25.4；Φ30.0；Φ38.1；Φ50.8；Φ76.2
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Square Shape:WxH(mm):
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5.0x5.0；10.0x10.0 ；15.0x15.0；
20.0x20.0；25.0x25.0；50.0x50.0
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Thickness Tolerance:
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0.5；1.0；1.5；2.0；3.0；4.0；
5.0；6.0；8.0；10.0; 50.0
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