Lithium Fluoride
- LIF
Lithium Fluoride (LiF) is a high-performance optical material known for its exceptional transmission from the deep ultraviolet through to the infrared, covering an impressive spectral range of approximately 0.12 µm to 6.5 µm. This wide coverage makes LiF ideal for UV laser systems, excimer optics, VUV spectroscopy, space-borne instruments, thermal imaging, and broadband analytical applications where both deep-UV and IR transparency are required.
LiF offers a low refractive index (~1.39 at 1 µm) and exhibits very low dispersion, enabling high optical clarity and stable imaging performance. As a non-hygroscopic material, it provides more robust handling compared with hygroscopic salts such as CaF₂ substitutes (e.g., NaCl, KBr), though it is softer and requires careful protection from mechanical wear. LiF also demonstrates excellent radiation resistance, making it suitable for space and high-energy optical environments.
At Global Optics UK, we manufacture and supply high-precision LiF windows, lenses, prisms, and laser-grade optical components, available uncoated or with specialised UV/IR anti-reflective coatings. Each optic is fabricated to strict tolerance and surface-quality standards, ensuring consistent performance for UV laser delivery, VUV research, thermal imaging, spectroscopy, and systems requiring broadband transmission, material stability, and optical purity.
Explore Related Optical Materials:
Magnesium Fluoride (MgF₂)
Calcium Fluoride (CaF₂)
Fused Silica (UV-grade)
FAQ
FAQ
Q: What is Lithium Fluoride (LiF) used for?
A: Lithium Fluoride is used in VUV and UV spectroscopy, excimer laser systems, aerospace and radiation-exposed optics, thermal imaging, and broadband UV–IR windows and lenses, thanks to its extremely wide 0.12–6.5 µm transmission range.
Q: Why choose LiF compared with other fluoride materials?
A: LiF offers exceptional deep-UV and VUV transparency, a low refractive index (~1.39), very low dispersion, strong radiation resistance, and non-hygroscopic stability, making it superior to hygroscopic salts such as NaCl and KBr.
Q: Is Lithium Fluoride hygroscopic?
A: No. LiF is non-hygroscopic and does not absorb moisture, giving it better durability and storage stability than common halide crystals.
Q: Is LiF suitable for high-power UV lasers?
A: Yes. LiF performs well in excimer and UV laser systems due to its good laser-damage threshold and deep-UV transmission, making it ideal for beam delivery and focusing optics.
Q: What optical components can be manufactured from LiF?
A: LiF can be fabricated into windows, lenses, prisms, wedges, and UV/IR optical elements, polished to high precision for scientific, defence, and industrial applications.
Q: Does LiF have good environmental and chemical stability?
A: Yes. LiF is chemically stable, non-reactive, and maintains its optical properties under typical laboratory and field conditions.
Its only limitation is mechanical softness, so care is required during handling.
Q: Can LiF be anti-reflective coated?
A: Yes. LiF optics can be supplied uncoated or with specialised UV/IR AR coatings, depending on the target wavelength range and application.
Q: Is LiF safe to handle?
A: LiF is non-toxic and safe to handle using standard optical-component precautions. Gloves are recommended to protect the soft surface from scratches or contamination.
Q: Where can I obtain technical data for LiF?
A: Full technical specifications, graphs, and datasheets for Lithium Fluoride are available here.