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Nonlinear
Crystals
Introduce
Nonlinear
Crystals
Laser
Crystals
AO
& EO Crystals
Optical
Crystals
YAG
YVO4
¦Á-BBO
Quartz
Sapphire
(Al2O3)
Spinel
(MgAl2O4)
Calcite
(CaCO3)
Magnesium
Fluoride (MgF2)
Calcium
Fluoride (CaF2)
Lithium
Fluoride (LiF)
Barium
Fluoride (BaF2)
Zinc
Sulphide (ZnS)
Zinc
Selenide (ZnSe)
Gallium
Arsenide (GaAs)
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Magnesium
Fluoride (MgF2)
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Magnesium
Fluoride is used for optical elements in the infrared where
extreme ruggedness and durability is required. Its useful
transmission range is 0.11¦Ìm - 7.5¦Ìm. Irradiation does not
lead to color centers. Magnesium fluoride is a rugged, hard
material which is resistant to thermal and mechanical shock.
Considerable mechanical shock is needed to cause cleavage
which is near perfect when it occurs. The natural form of
MgF2 is known as Sellaite. Magnesium fluoride is a positive
birefringent crystal grown normally to 135mm diameter by vacuum
Stockbarger technique, seeding along the C-axis.
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| Specifications
of MgF2 |
| Transmission
Range |
0.11
to 7.5¦Ìm |
|
Refractive
Index |
no=1.3836,
n e=1.3957 @ 0.405¦Ìm |
|
Reflection
Loss |
11.2% at 0.12¦Ìm (2 surfaces) |
|
Restrahlen
Peak |
20¦Ìm |
|
dn/dT |
+2.3 and +1.7 x 10-6/ ¡ãC at 0.4¦Ìm |
|
Density
|
3.177 g/cm3 |
|
Melting
Point |
1255 ¡ãC |
|
Thermal
Conductivity |
0.3 W/(m K) at 27 ¡ãC |
|
Thermal Expansion |
13.7 and 8.48 x 10-6/ ¡ãC |
|
Specific Heat Capacity, cal/(g K) |
0.24
@ 298K; 0.362 @ 1700K |
|
Dielectric Constant |
4.87 parallel and 5.45 perpendicular |
| Young's
Modulus (E) |
138.5 GPa |
| Shear
Modulus (G) |
54.66
GPa |
| Bulk
Modulus (K) |
101.32
GPa |
|
Elastic Coefficients |
C11=140.2
C12=89.5 C44=56.8
C33=204.7 C13=62.9 C66=95.7
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| Apparent
Elastic Limit |
49.64 MPa |
| Poisson
Ratio |
0.276 |
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