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YAG (Yttrium Aluminum Garnet, Y3Al5O12
) Windows
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YAG is the single
crystal
Y3Al5O12 and one of the hardest
and most durable materials. Undoped YAG crystal has a good transmission
from UV to IR and has high chemical resistance and
thermal conductivity.
The mechanical and chemical stability of YAG is
comparable to sapphire crystal, but YAG is unique with no birefringence
and available with higher optical homogeneity and surface quality.
Various high quality HR, AR, and partial reflective coatings are
available on YAG faces
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Shapes and Geometries
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Round Parallel Windows
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Square Parallel Windows
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* Other shapes and
geometries are routinely fabricated by Newlight Photonics.
Please contact us for your
specific needs.
Basic Properties of YAG Crystals
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Transparency Range: 250 - 4500 nm |
Transmission Curve |
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Density: 4.5 g/cm3 |
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Crystal Symmetry:
Cubic |
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Lattice Constants: a=b=c=12.01 Å |
Therm-Optic Coefficients:
dn/dT= 7.3 x 10-6 /oC
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Optical Homogeneity:
Δn < 10-6/cm
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Mohs Hardness: 8.5 |
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Thermal Conductivity: 14 W/m/K |
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Thermal Expansion Coefficients: |
α = 7.8 x 10-6/K
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Sellmeier equations
(λ
in mm )
:
n2=1+2.2820λ2/(λ2-0.01185)+3.27644
λ2/(λ2
-282.734) |
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Wavelength(nm) |
n |
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1400 |
1.8121 |
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1000 |
1.8197 |
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800 |
1.8245 |
Specifications of Sapphire Windows
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Orientation |
[111] within 5° |
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Dimension tolerance |
±0.1mm |
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Clear Aperture |
> 85% |
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Surface Quality |
10/5 Scratch and Dig
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Perpendicularity |
<10" |
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Parallelism |
<3" |
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Flatness
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λ/8 @ 632.8 nm
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Transmission
Wavefront Distortion |
<λ/8
/ inch @632.8 nm
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Bevel |
<0.25mm X 45° |
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