LiF & CaF2 Optical Window | Deep UV Fluoride Windows - Felix Glass
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- Felix Glass Co., Limited
- Issue Time
- Oct 21,2026
Summary
LiF and CaF2 fluoride crystal windows for VUV & deep UV spectroscopy. Felix Glass supplies precision LiF / CaF2 optical windows with UV AR coatings.
LiF & CaF2 Optical Window
Lithium Fluoride (LiF) and Calcium Fluoride (CaF2) are premium fluoride crystal optical substrates famous for deep ultraviolet and vacuum UV transmission. LiF reaches the shortest VUV wavelength, while CaF2 balances broad UV-MWIR transmission and better chemical stability, widely made into optical windows, prisms and spectrometer substrates with UV anti-reflection coatings.
Key Optical & Physical Properties
| Material | Transmission Range | Core Feature & Notes |
|---|---|---|
| Lithium Fluoride (LiF) | 0.11 μm – 6.5 μm | Best VUV cutoff down to 110nm; sensitive to moisture & thermal shock |
| Calcium Fluoride (CaF2) | 0.15 μm – 9.0 μm | Broad UV to MWIR, low dispersion, better stability, excimer laser grade |
Common Optical Components We Fabricate
- LiF vacuum UV windows, LiF prisms for VUV spectroscopy and vacuum measurement systems
- CaF2 optical windows, CaF2 lenses and prisms for excimer laser, DUV lithography
- Custom round, square, rectangular fluoride crystal windows for spectrometer chambers
- Thin fluoride substrates for fluorescence analysis and vacuum chamber viewports
Available Coating Options
We provide specialized UV coatings designed for fluoride crystal optical windows:
- VUV / Deep UV AR coating for LiF windows for vacuum ultraviolet applications
- 193nm, 248nm, 355nm excimer laser AR coating for CaF2 optical elements
- Broadband UV-VIS-MWIR anti-reflection coating for CaF2 multi-band optics
- Protective dielectric coatings to improve moisture resistance of fluoride crystals
Typical Application Fields
- Vacuum ultraviolet (VUV) spectroscopy and plasma diagnostic instruments (LiF)
- Excimer laser systems, semiconductor DUV lithography optics (CaF2)
- Fourier-transform infrared spectroscopy, UV fluorescence detection
- Aerospace UV sensors and space-grade low-dispersion optical assemblies
- High-temperature furnace viewports and vacuum optical measurement cells
Machining Capacity & Quality Control
Felix Glass uses high-purity optical-grade LiF and CaF2 single crystals. Surface scratch-dig grade up to 20/10, surface flatness can reach λ/4 @632.8nm. Fluoride crystals are brittle and require delicate polishing. We support custom drawings, prototype sampling and batch production with professional UV coating service.
Datasheet & Custom Inquiry
Send your target wavelength, drawing and coating specification for custom quotation of LiF or CaF2 optical windows.
Request Datasheet & Custom Quote