Barium fluoride (BaF2) Double-concave Lens
Barium fluoride has high transmittance from 200nm-11um region. Although this property is similar to that of calcium fluoride, barium fluoride has better transmission beyond 10.0um and is more resistant to higher energy radiation. Barium fluoride is commonly used for applications requiring transmission in the ultraviolet region.
Barium fluoride biconcave lens is similar to a plano-concave lens in that the focal length is negative, but the light incident in parallel diverges outward, and is often used in optical instruments,laser optical systems,infrared systems, such as Laser, LiDAR, infrared spectrometer, infrared camera, ultraviolet spectrometer, ultraviolet detector, etc.
The important parameters of a double-concave lens are: size, focal length, design wavelength, finish, face accuracy, eccentricity, substrate material and other attributes. Suitable parameters of double-convex lenses can be selected according to specific applications.
Our Company can provide Barium Fluoride Double-Concave Lenses with diameters from 2-300mm and thicknesses from 0.12-60mm (accuracy up to 20-10, 1/10L@633nm),coating AR, BBAR, AF or upon request.
Technical parameters of BaF2 Double-Concave Lens
Diameter | 2-300mm |
Focal length | 15-5000mm |
Thicknesses | 0.12-60mm |
Dimension tolerance | +0/-0.1mm |
Thickness tolerance | ±0.1mm |
Surface quality (scratch & dig) | 60-40, 40-20, or better |
Surface accuracy | λ/2, λ/4 or better |
Parallelism | 3' ,30'' |
Bevel | 0.1~0.3mm x 45 degree |
Clear aperture | >85%,>90% |
Coating | AR coating or cutom |
Material properties of BaF2
Optical Properties | |
Transmission Range | 0.15-14um |
Transmittance | >94%@0.35nm-10.8μm |
Refroetive Index | 1.462@2.58μnm |
Reflection Loss | 6.8%@2.58μm(bath sufaces) |
Absorption Coefficienet | 3.2×10-⁴@6μm |
Structure | Cubic Crystal System |
Cleavage Planes | <111> |
Physical Properties | |
Density|g/cm³ | 4.89 |
Melting Point 【C】 | 1386 |
ThermalConductivity 【w/(m*k)】 | 11.72 @286K |
Themal Expansion 【to-8/x】 | 18.1 @273K |
Knoop Hardness 【kg/mm2】 | 82 |
specific Heat Capacity【J/(kg×k)】 | 410 |
Dielectric Constant | 733 @1MHz |
Young's Modulus(E)[GPa] | 53.07 |
Shear Modulus(c)[GPo] | 25.4 |
Bulk modulus(k)[GPa | 56.4 |
Poissan Coefficient | 0.343 |
Chemical Propertie | |
Solubility/g/L | 1.7g @ 20℃ |
Molecular Weight /g/mo | 175.3238 |
Transmission curve
Barium fluoride (BaF2) has an optical transmittance of nearly 90% in the 200-9500nm.Moreover, barium fluoride can resist stronger high-energy radiation. However, the disadvantage of barium fluoride is its poor resistance to water. When exposed to water, significant degradation of performance occurs at 500°C, but it can be used in dry environments for applications up to 800°C.when handling optical components made of barium fluoride, gloves must always be worn and hands thoroughly washed after handling.
