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MgF2 (Magnesium Fluoride) Windows
MgF2 is positive uni-axial crystal with
very high optical transmittance from the vacuum UV to IR. It also
has a large resistance to mechanical and thermal shock, to optical
radiation, and is chemically stable, making it a very useful materials
for UV and IR optics.
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Shapes and Geometries
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Round Parallel Windows |
Square Parallel Windows |
* Other shapes and
geometries are routinely fabricated by Newlight Photonics.
Please contact us for your
specific needs.
Basic Properties of MgF2 Crystals
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Transparency Range: 130 - 9000 nm |
Transmission Curve |
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Crystal Symmetry: Tetragonal |
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Lattice Constants: a= b=4.621Å; c=3.053Å |
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Density: 3.18 g/cm3 |
Thermo-Optic Coefficients (@20 deg, 632nm)
dno/dT= 1.1 x 10-6 /oC
dne/dT= 0.58 x 10-6/oC
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Optical Homogeneity: Δn < 10-6/cm
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Mohs Hardness: 6 |
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Thermal Conductivity: 11.6 W/m/K |
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Thermal Expansion Coefficients: |
αa = 13.8 x 10-6/K
αc = 8.5 x 10-6/K
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Sellmeier equations (λ in µm):
no2=1+0.48755λ2/(λ2-0.00188) +
0.39875λ2/(λ2-
0.00895)+2.31204λ2/(λ2-
566.136)
ne2=1+0.41344λ2/(λ2-0.00136) +
0.50498λ2/(λ2-
0.00824)+2.49045λ2/(λ2-
565.108) |
| Wavelength(nm) |
no |
ne |
Birefringence
(Δn=ne-no) |
Walk-off Angle
at 45° |
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5000 |
1.3340 |
1.3428 |
0.023 |
-0.37 |
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2500 |
1.3642 |
1.3752 |
0.030 |
-0.45 |
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1064 |
1.3731 |
1.3847 |
0.032 |
-0.48 |
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800 |
1.3750 |
1.3867 |
0.032 |
-0.48 |
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532 |
1.3789 |
1.3907 |
0.032 |
-0.49 |
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355 |
1.3869 |
1.3991 |
0.034 |
-0.50 |
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266 |
1.3989 |
1.4116 |
0.035 |
-0.52 |
Specifications of MgF2
Components
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Orientation |
<001>,<110>,<100> with 5o |
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Dimension tolerance |
±0.05 mm |
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Wedge Angle tolerance |
0.1° |
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Surface Quality
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20/10 Scratch and Dig
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Optical Axis
Orientation |
+/-0.5° |
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Parallelism |
<15 arc sec |
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Perpendicularity |
<10 arc min |
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Flatness
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λ/4 @ 632.8 nm |
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Transmission
Wavefront Distortion |
<λ/4 @632.8 nm |
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AR-coating
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N/A |
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