UV–IR Optical Crystal
Barium Fluoride (BaF₂)
Optical crystal transmitting from deep-UV through long-wave infrared
Barium Fluoride is a broadband optical crystal with transmission extending from the deep ultraviolet through to the long-wave infrared. It is commonly specified in spectroscopy, FTIR, and radiation-exposed environments due to its low absorption and resistance to radiation darkening. While mechanically softer than many oxide crystals, BaF₂ is valued for applications requiring a single material solution across a very wide spectral range.
Is this material right for your application?
Use When:
Broad transmission from UV through long-wave IR is required
A single material must cover multiple spectral regions
FTIR or spectroscopy systems are used
Radiation resistance is important (space, nuclear environments)
Low absorption across a wide wavelength range is critical
Avoid When:
Mechanical strength and hardness are critical
Components will be exposed to moisture without protection
High abrasion or handling damage is likely
Cost-sensitive visible-only systems are being designed
High mechanical shock or vibration is expected
Consider Alternatives:
Calcium Fluoride (CaF₂) – improved mechanical strength and lower hygroscopicity
Magnesium Fluoride (MgF₂) – better durability for UV-focused applications
Zinc Selenide (ZnSe) – mid-IR performance with greater mechanical robustness
Explore Related Optical Materials
Calcium Fluoride (CaF₂)
Lithium Fluoride (LiF)
Zinc Sulphide (Multispectral)
Material specifications and frequently asked questions
FAQ
Q1. What wavelength range is BaF₂ used for?
BaF₂ has useful reference transmission from approximately 0.15 to 12.5 µm, with practical limits depending on thickness and surface condition.
Q2. Is BaF₂ hygroscopic?
It is slightly moisture-sensitive and should be handled and stored in controlled, dry conditions.
Q3. Is BaF₂ mechanically robust?
No. BaF₂ is relatively soft and brittle compared with oxide glasses and requires careful handling.
Q4. What are common alternatives to BaF₂?
CaF₂, LiF and ZnS may be considered depending on wavelength range, durability and environmental requirements.
BaF₂ is commonly used in FTIR spectroscopy and scintillation applications.
Anti-reflection coatings can be applied but must be compatible with fluoride substrates.
Not recommended for high-humidity or high-shock environments.