VUV / Deep-UV Fluoride Crystal
Lithium Fluoride (LiF)
Very short-wavelength transmission for VUV, deep-UV and specialised spectroscopy optics
Lithium Fluoride (LiF) is a synthetic fluoride crystal notable for an exceptionally short ultraviolet transmission edge, making it valuable for vacuum-UV and deep-UV optics. It also transmits into the mid-infrared. LiF is soft, cleaves readily and has slight water solubility, so optical surfaces require careful fabrication, dry handling and environmental protection.
Is this material right for your application?
Use When:
Deep-UV or vacuum-UV transmission is required
Spectroscopy systems operate below standard UV limits
Maximum short-wavelength transmission is critical
Applications are strictly laboratory-based
Handling and environment can be carefully controlled
Avoid When:
Moisture exposure cannot be controlled
Mechanical durability is required
Handling conditions are not strictly managed
Cost or ease of handling is a priority
Consider Alternatives:
Magnesium Fluoride (MgF₂) – improved durability with UV performance
Calcium Fluoride (CaF₂) – broader usable wavelength range
Fused Silica – easier handling and fabrication
Explore Related Optical Materials
Magnesium Fluoride (MgF₂)
Calcium Fluoride (CaF₂)
Barium Fluoride (BaF₂)
Material specifications and frequently asked questions
FAQ
Q1. What wavelength range is LiF used for?
A representative 2 mm LiF specimen transmits approximately from 0.116 to 7.4 µm.
Q2. Is LiF suitable for VUV and deep-UV optics?
Yes. Its short-wavelength transmission edge makes it useful where many other optical crystals do not transmit.
Q3. Is LiF moisture-sensitive?
LiF is slightly water soluble, so polished surfaces should be protected from prolonged moisture exposure.
Q4. What are common alternatives to LiF?
MgF₂ and CaF₂ may be considered where greater durability or a different UV/IR bandwidth is required.
Excellent VUV and deep-UV performance
Soft and brittle material
Best used in low-humidity environments