CaF2 氟化钙晶体窗片

Calcium fluoride is a superb optical material. It is often chosen by laser optics manufacturers for its wide transmission range, low absorption and low refraction. Compared to other fluorides, CaF2is much more resistant to moisture and to thermal shock. CaF2 optics are commonly used in imaging, thermal imaging, astronomy, microlithography and high-power lasers.

Basic properties

Syngony

Cubic

Symmetry class

M3m

Lattice constants

A=5.462 c=a

Cleavability

(111)

Refractive index at Nd

1.4349

Refractive index at Nf -Nc

0.0043

Refractive index at N10.6

1.2996

Reflection loss

5.5 %

Transmission range

0.15-9 μm

Density

3.18 g/ cm3

Melting point

1360 ° С

Thermal conductivity index

9.71 Вт/(м K)

Thermal expansion index

18.5 x 10-6/К

Knoop hardness

158.3 kg/mm2 (100)

Specific heat

854 J/(kg K)

Dielectric constant (f=1 MHz)

6.76

Young’s Modulus, E

75.8 GPa

Shear modulus, G

33.77 GPa

Modulus of volume elasticity, K

82.71 GPa

Elastic strength

36.54 MPa

Poissont ratio

0.26

Solubility

0.0017 g / 100 g of water at T= 20 °C

Molecular weight

78.08

CaF2 Transmission

λ, μm

Refractive index

0.19

1.51

0.21

1.49

0.25

1.47

0.33

1.45

0.41

1.44

0.88

1.43

2.65

1.42

3.90

1.41

5.00

1.40

6.20

1.38

7.00

1.36

8.22

1.34

Products

Diameter/Width

12.7-101.6 +/-0.2 mm

Thickness/length

2-12 +/-0.2 mm

Surface quality

As-cut, 80/50, 60/40 per MIL-0-13830

Wedge

< 5’

Clear aperture

90%

Length/Width

7-25.4 +/-0.1 mm

Thickness/length

7-25.4 +/-0.1 mm

Surface quality

80/50, 60/40 per MIL-0-13830

Corner tolerance

+/-10’’

Total surface error

λ / 2

Diameter/Width

12.7-101.6 +/-0.2 mm

Thickness/length

2-10 +/-0.1 mm

Surface quality

80/50, 60/40 per MIL-0-13830

Wedge tolerance

+/- 3’

Total surface error

λ / 2

Clear aperture

90%