CaF2 Windows
This kind of windows is made from Custom-made CaF2. 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 um to 9 um) 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.
| Specifications | Standard | High Precision |
|---|---|---|
| Material | CaF2 | |
| Dimension Tolerance | +0.0/-0.2mm | +0.0/-0.02mm |
| Thickness Tolerance | +0.0/-0.2mm | +0.0/-0.05mm |
| Flatness | λ/2@632.8nm | λ/10@632.8nm |
| Surface Quality | 60-40 | 40-20 |
| Clear Aperture | >85% | >90% |
| Parallelism | 1 arc min | 10 arc sec |
| Bevel | 0.25mm x 45° | |
| Coating | Uncoated, AR, HR, PR, etc. | |
| Standard CaF2 Window | |
|---|---|
| Round Shape: DiaxT(mm) | Φ10.0x3.0, Φ12.7x3.0, Φ15.0x3.0, Φ20.0x3.0, Φ25.0x3.0, Φ25.4x3.0, Φ30.0x3.0, Φ50.8x6.35 |
| Square Shape: WxHxT(mm) | 5.0x5.0x1.0, 10.0x10.0x1.0, 15.0x15.0x2.0, 20.0x20.0x2.0, 25.0x25.0x2.0, 50.0x50.0x6.0 |
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| High Precision CaF2 Window | |
|---|---|
| Round Shape: DiaxT(mm) | Φ10.0x6.0, Φ12.7x6.0, Φ15.0x6.0, Φ20.0x6.0, Φ25.0x6.0, Φ25.4x6.35, Φ30.0x.6.35, Φ50.8x10.0 |
Note: Other sizes, material and coating are available upon request.
