Barium Fluoride as a Crystal for Optics
Barium fluoride as optical material for VIS/IR
Hellma Materials BaF2 offers exceptionally high transmission in the visible wavelength range as well as in the extended IR range up to 12 µm. This means that BaF2 can be used as a broadband optical material in VIS/IR dual channel systems for visible light and thermal radiation. This means that BaF2 can be used as a broadband optical material in VIS/IR double channel systems for visible light and thermal radiation. Another advantage of BaF2 is its lower refractive index compared to other optical materials. This reduces transmission losses due to Fresnel reflection.
The most important facts about BaF2 as an optical crystal
Refractive index nd =
1.47447
low refractive index
enables an almost unchanged beam path
Abbe number 𝜈d =
81.61
Low spectral dispersion
minimises chromatic aberration
Thermal conductivity λ=
11.72
@ 13 °C [W/(m*K)]
Compensates for high CTE
Hellma Materials BaF2 crystals as solutions for your optical challenges
Barium fluoride (BaF2) from Hellma Materials is a proven optical material with outstanding properties:
- Broad transmission spectrum: Excellent transmission in the VIS and IR range.
- Low dispersion: Minimises chromatic aberrations.
- High resistance to ionising radiation: can be used in space.
- Large diameters: Up to 360 mm possible for demanding applications as lenses and windows.
Thanks to these properties, our BaF2 crystals are the first choice for:
- Astronomy: Optics for astronomical instruments
- Security technology: thermal imaging and night vision devices with VIS channel
- Security industry: IR laser optics
- Environmental analysis: IR spectroscopy
Advantages of our barium fluoride
| Feature | Value | Advantage |
|---|---|---|
| Thermal conductivity | λ = 11.72 @ 13 °C [W/(m*K)] | Compensates for high CTE |
| Low spectral dispersion | 𝜈d = 81.61 | Minimises chromatic aberrations |
| High, broadband transmission from the VIS to the IR range | 200 nm to 12 µm | Excellent transmittance in the VIS and IR range |
| Available size of semi-finished products | up to 360 mm | for demanding applications |
Features of the BaF2 at a glance
| Optical, mechanical, thermal properties | |
|---|---|
| Refractive index @ emission wavelength | 1.54 @ 220 nm 1.50 @ 310 nm |
| Density [g/cm³] | 4,89 |
| Thermal conductivity [W m-1 K-1] | 11.72 |
| Linbear expansion coefficient [10-6 K-1] | 18.1 |
| Crystal structure | cubic |
| Hygroscopic | no |
| Forms of delivery | |
|---|---|
| Diameter max. [mm] | 360 |
| Thickness max. [mm] | 150 |
| Surface quality | finely ground/polished |
Your advantages with semi-finished products from Hellma Materials:
Flexibility in material size: Customised solutions for your specific requirements.
Optimised performance: Achieve maximum optical precision and efficiency.
Reliability: Trust in a proven material with a long service life.
Quality control: All measurement technology including laser laboratory in-house.
