Refractive index database

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Optical constants of BaF2 (Barium fluoride)
Zheng et al. 2023: n 0.22–1.7 µm; 21 °C

Wavelength: µm

Complex refractive index (n+ik)[ i ]

n   k   LogX   LogY   eV

Derived optical constants

Dispersion formula [ i ]


Conditions & Spec sheet

n_is_absolute: false
wavelength_is_vacuum: false
temperature: 21.1 °C


21.1 °C. The supplementary materials of the original publication contain coefficients of the Sellmeier formula for multiple temperatures in the range of 21 °C to 368 °C.


Q. Zheng, X. Wang, D. Thompson. Temperature-dependent optical properties of monocrystalline CaF2, BaF2, and MgF2, Opt. Mater. Express 13, 2380–2391 (2023) (See Supplementary materials)


[Expressions for n]   [CSV - comma separated]   [TXT - tab separated]   [Full database record]


Barium fluoride, BaF2

BaF2, or barium fluoride, is a crystal that offers a wide transmission range, spanning from the ultraviolet into the mid-infrared regions. This material is commonly used in specialized optical applications such as scintillators in high-energy physics experiments, and as windows and lenses in infrared spectroscopy systems. It possesses a relatively low refractive index and high resistance to radiation damage, which makes it especially useful in extreme conditions. Additionally, BaF2 has fast scintillation response times, making it advantageous in fast-timing applications. One drawback, however, is that the crystal is hygroscopic, making it sensitive to moisture and requiring proper storage and handling to maintain its optical properties. It also has a lower resistance to thermal and mechanical shock compared to other fluoride crystals, which can be a consideration depending on the intended application. Despite these limitations, BaF2 remains a highly valuable material for specialized optical and photonic applications, owing to its broad transmission range and resilience to high-energy radiation.

Other names

  • Barium difluoride
  • Barium(II) fluoride

External links